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Will You Tune In to Greatest American Dog Tonight?

PetSugar — Thu, 10 Jul 2008 14:45:50 -0700

I've made no secret of my love for Groomer Has It so I'm happy North and I will soon have another furry series to get into! The Greatest American Dog premieres tonight – I'm definitely tuning in, are you?

Meet the Contestants of Greatest American Dog

PetSugar — Wed, 09 Jul 2008 16:10:22 -0700

I'm super psyched for the Greatest American Dog for several reasons – there's quite the cast of characters to watch! Bringing 12 teams of pooches and owners, I can't wait to see how the pageant dogs measure up against the home-trained pups, the purebreds to the mixed, and what goes down when all 24 move in together! Each week a pair will be eliminated 'til one wins the crown . . . and a $250,000 prize! Check out the contestants here and tune in Thurs., July 10 at 8 p.m. for the fur-flyin' premiere!

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Another Sneak Peek at the Greatest American Dog!

PetSugar — Fri, 06 Jun 2008 15:10:20 -0700

Remember when I hinted about that show Greatest American Dog? Well, I've got some more info courtesy of my pal, BuzzSugar. This new reality/ competition series pits 12 teams of pups and owners – with varying levels of training – against each other in games that test the training abilities and train-ability of the duos. Oh, yeah and they get to live together, too. Awesome. To top it all off, the winning team will walk away with a $250,000 cash prize – that's lots of doggie treats! Jarod Miller, who you may recognize from Petfinder, will host this show premiering July 10 (8:00-9:00 p.m., EDT/PDT) on CBS. Get a sneak peek in the promo video below.

Do You Have America's Greatest Dog?

PetSugar — Thu, 29 May 2008 00:30:16 -0700

If you've always wanted to be on TV, and you have a pup with some serious talent, then have I got a contest for you! I just stumbled across CBS's casting call for their new reality show tentatively called America's Greatest Dog, that puts dogs' (and owners') talents in the spotlight as they try to nab the title of Top Dog. That means, if I know anything about reality television, there will be drama, a few brawls (more likely between humans than canine), and a really swank house. I can't wait!

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Lyme disease and related tick-borne infections

FitSugar — Wed, 08 Oct 2008 17:35:15 -0700

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

Lyme Disease Rates Double in Past 15 Years

The annual number of people newly infected with Lyme disease has doubled from around 10,000 cases per year in the early 1990s to about 20,000 cases per year now. Improved diagnosis and reporting probably contribute to this increase. In the United States, Massachusetts, New Jersey, and Pennsylvania have reported the highest number of Lyme disease cases in recent years. People ages of 5 - 14 years and 45- 54 years are at highest risk for contracting Lyme disease.

New Guidelines for Treatment of Neurological Lyme Disease

Most cases of Lyme disease can be prevented or cured with prompt antibiotic treatment following a deer tick bite. However, neurological complications can later develop in some patients. In 2007, the American Academy of Neurology released new guidelines for the treatment of nervous system Lyme disease. The guidelines recommend that patients with severe disease receive a 2 - 4 week course of intravenous antibiotics (penicillin, ceftriaxone, or cefotaxime). Patients with milder neurological cases may do well with a 2 - 4 week course of oral doxycycline. No guidelines currently recommend long-term antibiotic treatment for any stage or complication of Lyme disease.

Introduction

Lyme disease is the most commonly reported vector-borne disease in the United States. Vector-borne infections are transmitted by insects.

The Lyme disease infection in the U.S. is caused by a spirochete called Borrelia (B.) burgdorferi. A spirochete is a bacteria-like organism with a cylinder-like shape surrounded by an outer membrane.

Lyme researchers have the completion of DNA encoding of B. burgdorferi. Researchers learned that certain proteins coat its outer surface. These proteins, collectively called Osp, are responsible for attaching the spirochete to cells in humans and other mammals.

The vector that carries B. burgdorferi in the U.S. Northeast and North Central states is the Ixodes scapularis tick. The Ixodes scapularis tick goes through three stages over the course of about two years:

It is born from eggs as a larva.
It develops into the nymph stage.
It develops into the adult stage.

Cycle of Infection in the Northeast and North Central U.S. For Lyme disease to exist in these regions, three factors must come into close contact:

The Borrelia (B.) burgdorferi spirochete
The spirochete's host, the Ixodes scapularis tick
The mammal for the tick to bite

The following describes the most common cycle in the Northeast and North Central U.S. by which the Lyme disease infection eventually reaches a person:

The cycle of infection is related to the tick's life cycle, which requires 2 years to complete. The tick typically first picks up the spirochete during its larva stage, when it needs a blood meal to mature further.
The tick's initial meal is typically blood from the white-footed mouse, which is commonly infected with Borrelia burgdorferi. After it dines on the infected blood, the tick then becomes a carrier of this spirochete.
Borrelia burgdorferi lodges in the tick throughout one of both of its following life stages, nymph and adult. It is during these stages that the infection is passed on to other animals, including humans. Nymph ticks emerge around mid-June and can be about the size of poppy seeds. They are very difficult to spot and are estimated to be responsible for 90% of all Lyme disease cases. Adult ticks can be as large as a raisin after feeding, and easy to spot, but they usually prefer their dinner on the white-tailed deer.
The infected nymph or adult tick crawls (it does not fly or jump) onto another animal, which can be mice or larger animals, such as deer, birds, or humans. If the tick bites these animals, it may then infect them with the B. Burgdorferi spirochete. (It should be noted that infected humans cannot pass the spirochete on to other humans by any means, including infected blood or urine or sexual contact.)
A tick can feed for several days while being imbedded in the skin, after which it falls off. The tick's bite is painless, however, so only about half of people with Lyme disease recall being bitten.

Cycle of Infection in the Northwest. In the Northwest, the infecting insect is the Western blacklegged tick, Ixodes Pacificus. Here, the frequency of Lyme disease is much lower than in the other two regions because the animal carrier of the infection is the dusky-footed wood rat. This animal is bitten and infected by the Ixodes neotomae tick, which does not bite humans. The actual tick that spreads B. burgdorferi to people is Ixodes pacificus, which must feed first on an already infected wood rat.

The two other important infections carried by the Ixodes scapularis tick are human granulocytic anaplasmosis (HGA) and babesiosis. Although they are both borne by the same tick as Lyme disease, all three of these infections are entirely different diseases.

Risk for Coinfection. Because Lyme disease, HGA, and babesiosis can all be carried by the same tick, there is some risk for co-infection with two or more of these organisms. The risk, however, is not wholly known. Studies have reported that 2 - 25% of ticks in several high-tick locations carry both HGA and Lyme. In one study of patients located in high-risk areas in New England, 39% had more than one of these infections transmitted by the Ixodes tick. There is no evidence that co-infection with one or more of these infections causes a more severe condition than either infection separately.

Symptoms

Symptoms of Lyme disease are diverse and often occur in early and late phases. They vary widely from person to person. Any one symptom may fail to appear, and symptoms may overlap in various combinations. Death from Lyme disease is very rare and occurs only in a few cases in which the heart is severely affected.

Stage 1. In the majority of cases, the first sign of early Lyme disease is the appearance of a bull's-eye skin rash. It usually develops about 1 - 2 weeks after the bite, although it may appear as soon as 3 days, and as late as 1 month. In some cases, it is never detected. Flu-like symptoms (joint aches, fever, and general fatigue) commonly develop.
Stage 2. Untreated, the infection spreads through the bloodstream and lymph nodes within days to weeks, involving the joints, nervous system, and possibly the heart. Multiple rashes may erupt in other places. If the infection affects the nervous system in stage 2, it most often causes weakness or paralysis in the nerves of the face (Bell's palsy) or in nerves of the spine.
Stage 3. If the disease remains untreated, a persistent infection can occur after a few weeks or months, leading to prolonged bouts of arthritis and neurologic problems, such as concentration problems or personality changes. Fatigue is a prominent feature of both early and late stages.

Evidence suggests that up to 90% of patients with Lyme disease exhibit a rash a few days to a month after a tick bite. The rash, known as erythema migrans, usually first appears on the thigh, buttock, or trunk in older children and adults, and on the head or neck in young children.

The bull's eye rash, which is commonly believed to be the classic sign of Lyme disease, may take the following course:

It can first appear as a pimple-like spot, which expands over the next few days into a purplish circle. The circle may reach up to 6 inches in diameter with a deeper red rim. In some cases the ring is incomplete, forming an arc rather than a full circle.
The center of the rash often clears or may turn bluish. Or secondary concentric rings may develop within the original ring, creating the bull's-eye pattern. Over the next several weeks, the circular rash may grow to as large as 20 inches across.
Patients often describe the sensation of the rash as burning rather than itching.

It is important to note that in one study, only 9% of patients diagnosed with Lyme disease exhibited this classic pattern. Nearly 60% had a rash that was more general in appearance and 32% had a circular dense red rash.

In most patients, any rash fades completely after 3 - 4 weeks, although secondary rashes may appear during the later stages of disease.

A flu-like condition is the most common sign of Lyme infection, and it can occur with or without a rash. Symptoms can last from 5 - 21 days and may include:

Fatigue
Chills and fever (100 - 103° F)
Headache (usually most prominent at the back of the head)
Joint aches (usually in the large joints)
Stiff neck
Backache
Swollen glands (in the area around the tick bite or elsewhere)
Less often, nausea, vomiting, and sore throat occur

Some experts recommend that children in high-risk areas be tested for Lyme in the summer months if they have the most common Lyme symptoms (fever, headache, joint aches) -- even if they have no tell-tale rash. Severe and sustained flu symptoms without the rash in such patients may indicate the presence of human granulocytic anaplasmosis (HGA) or babesiosis -- the other infections carried by the Ixodes tick.

Joint pain can arise at any time after the appearance of a skin rash. In the absence of a rash, arthritic symptoms may be the first indication of Lyme disease. Or, as suggested by some studies, it can develop months after the disease has been diagnosed. Arthritic symptoms may occur as follows:

Aches, stiffness, and swelling, sometimes massive, of large joints, such as the knee, elbow, or shoulder. One or both knees are affected most often. The ankle, wrist, jaw, and finger joints are involved less often.
Typically, no more than three joints are affected during the course of the disease. If several joints are involved, they tend to be asymmetrically distributed.
Joint pain flare-ups are often accompanied by muscle pain.
Arthritis symptoms usually last for a few days or weeks and are interspersed with longer periods during which the joints feel fine.
The severity and frequency of attacks peak within 1 - 2 years then decrease and usually resolve, even without treatment.

About 15% of untreated patients develop neurologic symptoms. They can occur in all stages of the disease and can affect any part of the nervous system.

Common Early Neurologic Symptoms. Most often, neurologic symptoms first appear while the initial skin rash is still present or within 6 weeks after its disappearance. Sometimes they are the first symptoms that the patient experiences. The most common neurologic symptoms may be headaches, sleep problems, and mood disturbance. Memory problems can also occur. Neurologic symptoms typically improve or resolve within a few weeks or months, even in untreated patients.

Bell's Palsy. In 5 - 10% of untreated Lyme patients, the facial nerve is affected, which results in Bell's palsy. This is a sudden weakness and drooping of the facial muscles and eyelid on one side of the face. Nerves around the facial area may also cause numbness, dizziness, double vision, and hearing changes. Another common neurologic problem is pain in the lower spine. It resembles low back pain from arthritis (although in the case of Lyme disease the skin near the spine may have abnormal sensations). Of note, Lyme disease has been observed in more than half the children who develop Bell's palsy.

Symptoms of Meningitis. In about 10 - 15% of patients, the infection takes place in the membranes that surround the brain and spinal cord (called meningitis). This can cause:

Episodes of headache not relieved by over-the-counter medication
Mild stiff neck
Sensitivity to light

Symptoms of Lyme Encephalopathy. In some cases of untreated disease, the infection causes a condition called Lyme encephalopathy or neuroborreliosis. This causes the following symptoms:

Unexplained mood changes
Depression
Trouble concentration and remembering
Irritability
Feelings of "pins and needles" or numbness in the arms or legs

Other Neurologic Symptoms.

If the infection affects the white brain matter, symptoms resemble multiple sclerosis.
If the infection occurs in the nerves affecting the skin, some patients experience pricking, tingling, or creeping feelings.
Children have a higher risk than adults for neurologic effects on the eye. (This is still rare, however.)

The infection may affect electrical conduction to the heart and cause symptoms suggesting heart rhythm disturbances:

Palpitations
Shortness of breath
Chest pain
Dizziness
Fainting can occur if the infection affects the heart

These symptoms almost never produce serious problems in people without other types of heart disease.

Symptoms in the eyes have been reported at every stage. Conjunctivitis ("pink eye") may be a symptom in the early stages. In late, untreated Lyme disease, neurologic problems can affect the eye, causing pain and sensitivity to light.

Risk Factors

Since 1991, when Lyme disease became a reportable disease, annual cases have doubled. (This increase is probably both due to increased infection rates as well as better diagnosis.) In general, about 21,000 cases of Lyme disease are now reported in the U.S. each year.

Anyone exposed to ticks is at risk for Lyme disease and other tick-borne diseases. Pets are also at risk. Naturally, anyone who is regularly outside in areas where tick rates are high has a greater than average risk for becoming infected.

Age. The highest reported incidence of Lyme disease occurs among children 5 - 14 years old and adults 45 - 54 years old.

Sex. Men and women are equally at risk.

In general, the risk for developing Lyme disease after a tick bite is only between 1 - 3%. The risk varies depending on different factors:

The longer the tick has fed, the greater the risk. In fact, in one study, no individuals developed Lyme disease after being bitten by a nymph tick for fewer than 72 hours. The risk was 25% in people on whom the tick had been feeding for longer than 72 hours.
Nymph ticks carry a greater risk than adult ticks, probably because they are often too small to be detected (about the size of a pinhead). In addition, only nymph ticks that are at least partially swollen when removed pose any significant risk. (This suggests that they have feeding for a prolonged period.)

Locations in the U.S. Lyme disease has been reported in nearly all U.S. states. However, most Lyme disease cases are concentrated in the northeastern, mid-Atlantic, and north central states. Although Lyme disease was named for a town in Connecticut where the first American cases of the disease were described, in recent years Massachusetts, New Jersey, and Pennsylvania have reported the greatest number of cases.

Worldwide Locations. Pockets of Lyme disease exist around the world. The disease is common in Europe, particularly in forested areas of middle Europe and Scandinavia. The Borrelia family is also responsible for tick infections in Europe, but different subspecies (B. garinii and B. afzelii) may be more common there and cause slightly different symptoms. The infection has also been reported in Russia, China, and Japan.

Deer ticks thrive in grassy areas that have low sunlight and high humidity. Woodlands and fields are prime habitats, but these ticks can also be found in the long grasses adjacent to beaches. The ticks are not confined to rural settings. In suburban areas, they can live in overgrown lawns, groundcover plants, and leaf litter.

The exact time of year for risk depends on a geographic region’s seasons and how they affect the tick’s breeding cycle. In general, the highest risk for Lyme disease onset is from June through August, and the lowest risk is from December through March.

Complications

Prompt treatment with antibiotics is very effective in curing Lyme disease in nearly all infected people, including children. One study showed that the long-term outcome of patients with Lyme disease who are treated with antibiotic therapy is excellent. However, even if Lyme disease has been successfully treated, it may be possible to become reinfected with Lyme disease again at a later date. The risk appears to occur only in patients who had been treated for the rash. In those who also developed arthritic symptoms, the antibody response appears to persist and prevent reinfection.

People at highest risk for persistent symptoms are those who go the longest before treatment. Fortunately, public vigilance has significantly reduced the rates of late-stage Lyme disease. Antibiotics given at late stages will relieve symptoms in most people, although about 5% may continue to have problems. Also at risk for persistent symptoms are those who show evidence of having severe infections. Retreatment at later stages has been shown to be effective in about three quarters of these patients.

Left untreated, Lyme disease can spread (disseminate). The infection may affect almost any part of the body and cause the following complications:

Severe arthritis
Persistent fatigue
Mood disturbances and loss of concentration
Neuropathy (numbness, tingling, or other odds sensations in the hands, arms, feet or legs)
Life-threatening disorders affecting the heart, lungs, or nervous system can occur, but are very rare.

Arthritis. Without treatment, 60% of patients develop intermittent joint inflammation, especially in the knees. Lyme arthritis usually responds to a 28-day course of oral antibiotics (doxycycline, amoxicillin, or cefuroxime). A small number of patients may require intravenous antibiotics.

If the arthritis persists or joint swelling recurs after several months, patients may be treated by another 4-week course of oral antibiotics or 2 - 4 weeks of intravenous antibiotics (ceftriaxone). If symptoms still persist, nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroid injections, or disease-modifying antirheumatic drugs may be recommended by a rheumatologist. In severe cases, patients may require surgery (synovectomy) to reduce joint inflammation.

Persistent Neurological Disorders. In general neurological problems persist in 5% of patients, although some studies have reported much higher rates of up to 50%. Persistent symptoms usually include headache, attention and memory problems, and depression. Patients may also experience neurologic pain, numbness, or abnormalities in the face. Neurologic symptoms generally resolve and improve within a year.

Heart Problems. About 5% of untreated patients experience acute heart events from electrical conduction problems caused by the infection. Heart symptoms can appear within a few days to several months after the onset of disease. They include:

Arrhythmias (irregular heartbeats)
Pericarditis (inflammation of the lining of the heart), which occurs in about 5% of patients

Lyme-related heart problems almost always resolve without serious consequences within a week. About 30% of patients may need a temporary pacemaker, however. In very rare cases, these heart rhythm abnormalities have been fatal. There is some debate about whether there are any long-term consequences to the heart, such as the development of heart failure in some patients. One study of patients who had Lyme-related heart effects reported no greater long-term risk for heart problems than in people without a history of Lyme disease.

Miscellaneous Complications. Other complications reported include:

Problems in the eye, including swelling that can cause pain and sensitivity to light
Hepatitis (inflammation in the liver)
Respiratory difficulties

Infections in the Pregnant Patient. The occurrence of any infection during pregnancy is of special concern. While the current research indicates that complications during pregnancy due to Lyme disease are very rare, pregnant women should still adhere scrupulously to preventive measures.

Some studies indicate that Borrelia burgdorferi may be transmitted to the fetus during pregnancy, with the risk highest during the first trimester. If this occurs, however, it is likely to be very rare and not an issue of great concern. There is no evidence of any severe effects in the offspring of infected pregnant women.
There are no reports of human infant Lyme disease infection from breast-feeding. Studies on animals, however, have reported transmission of the organism to infant mice through breast milk, but these findings do not appear to be applicable to people.

Lyme disease is a curable condition. Nearly all patients (95%) improve after a short course of antibiotics. In very rare cases, patients continue to complain of persistent non-specific symptoms, such as fatigue, muscle aches, cognitive problems, and headache lasting years after completing antibiotic treatment for the initial infection.

This syndrome, which resembles chronic fatigue syndrome (CFS) or fibromyalgia, is referred to as post-Lyme disease syndrome. In the past, it has been called “chronic Lyme disease.” However, based on many reviews of scientific literature, experts strongly believe that Lyme disease does not have a chronic state. According to the 2006 guidelines from the Infectious Diseases Association of America, post-Lyme disease syndrome is the preferred name for this condition.

Patients are considered to have this syndrome if they still have symptoms 6 months after treatment. Most importantly, there must be definitive evidence that the patient was originally infected by the B. burgdorferi spirochete. If there is no documented evidence of infection, it could be that the patient never had Lyme disease, or may be experiencing a new or different type of illness. If the patient did have Lyme disease, symptoms should eventually resolve without additional antibiotic treatments.

Experts strongly advise against prolonged antibiotic treatment. There is no evidence that long-term antibiotics help treat post-Lyme disease syndrome symptoms. In addition, long-term antibiotic treatment carries its own serious risks, such as the development of antibiotic-resistant superbugs.

Diseases with Similar Symptoms

Many other illnesses can mimick various features of Lyme disease. Depending on the symptoms, a doctor may be able to perform the evaluations necessary to rule out other conditions.

Other infections can produce fever, headache, muscle aches, fatigue, and some of the neurologic or cardiac features of early Lyme disease. Some are transmitted by the same tick as Lyme disease.

Co-Infections Transmitted by the Ixodes Tick. Babesiosis and human granulocytic anaplasmosis (HGA) are transmitted by the same tick that carries Lyme disease. People may be co-infected with one or more of these infections, all of which can cause flu-like symptoms. If these symptoms persist and there is no rash, it is less likely that Lyme disease is present. Still, diagnosing a co-infection is difficult.

Other Spirochete Infections. Leptospirosis is a spirochete infection spread through animals or contaminated water that most often affects young people during the summer or fall.

Other Tick-Borne Infections. A number of other tick-borne diseases may resemble Lyme disease, although they are more common in parts of the U.S. where Lyme disease is less prevalent.

Tick-borne relapsing fever (TBRF), a flu-like illness that occurs in mountainous areas of the West during the summer, may be misdiagnosed as Lyme disease. The antibiotic doxycycline may be prescribed to patients who have been bitten by ticks suspected of carrying TBRF, to help prevent development of the disease.
Rocky Mountain spotted fever, which is also transmitted by ticks, is most prevalent in the south central and southeastern parts of the United States, but occurs throughout North and South America. The most characteristic symptom is a spotty rash that appears 5 - 10 days after infection. The disease is caused by ticks that carry the bacterial organism Rickettsia rickettsii, and is considered the most severe tick-borne illness in the United States. Unlike Lyme disease, which is rarely fatal, Rocky Mountain spotted fever causes death in 10% of all cases. Recent outbreaks of Rocky Mountain spotted fever have been linked to increases in wild dog populations.
A tick-borne infection called by human monocyte ehrlichiosis (HME), carried by the Lone Star tick, strongly resembles Lyme disease, including a similar rash. It is not caused by the Lyme spirochete, however, and has been identified in patients who live in the southern United States.

Researchers speculate that ticks may be responsible for other diseases not previously thought to be carried by these vectors. For example, the Bartonella family of bacteria causes cat-scratch fever (which is transmitted from cat to cat by fleas) and trench fever (historically transmitted by lice).

Allergic Reaction to the Tick. If a rash, even ring-shaped, appears hours rather than days after a tick bite, it is most likely an allergic reaction to the tick, not a symptom of Lyme disease.

Other Insect Bites. Not every rash seen in regions where Lyme disease is common is caused by a tick. The bites of many insects and spiders can cause a skin reaction.

A number of autoimmune diseases have chronic and low-level symptoms that may be confused with Lyme disease.

Systemic lupus erythematosus (SLE) produces a rash (usually on the face), flu-like symptoms, and arthritis, but they usually develop very slowly over time.
Rheumatoid arthritis or Reiter syndrome causes pain, swelling, or stiffness of the joints that may be confused with post-Lyme disease syndrome.
Scleroderma has a limited form of the disease called morphea, which produces hard patches of skin. Some studies have even reported an association between B. burgdorferi and some cases of morphea. However, the evidence is weak and if it exists it is possibly limited to a specific variant in Europe and Asia. There is no association between severe scleroderma and Lyme disease.
In children, juvenile rheumatoid arthritis or rheumatic fever, which follows strep throat, should be considered.

A number of conditions cause chronic fatigue and joint and muscle aches that resemble descriptions of post-Lyme disease syndrome:

Mononucleosis -- this viral infection is common in adolescents
Chronic fatigue syndrome (CFS)
Fibromyalgia
Depression (may include persistent fatigue and vague aches and pains)

The early neurologic symptoms of Lyme disease (headache, stiff neck, and fatigue) can easily be mistaken for viral meningitis. Children with viral meningitis are more likely to have a higher fever. Patients with Lyme disease often have other symptoms, such as the bull's-eye rash.

Diagnosis

Proper diagnosis of Lyme disease is important. A diagnosis of Lyme disease is straightforward if the patient meets the following criteria:

Lives in an area of tick-infestation
Has the tell-tale bulls-eye rash
Has other symptoms (headache, joint aches, malaise, flu-like symptoms)

If the patient meets all the criteria, except the rash, the doctor may undertake the enzyme-linked immunosorbent assay (ELISA) or the Western Blot test.

In some cases, if the patient seeks a diagnosis within the first 2 - 3 weeks, the doctor may take a sample of the skin or of the blood. If Lyme spirochete is present, it may be identified in the laboratory in a culture medium (a substance in which the organism can thrive and reproduce). This is necessary only if a doctor suspects Lyme but the diagnosis is not clear.

If the infection is not obvious from the patient's history and physical symptoms, but Lyme disease is suspected, the doctor may run tests for evidence of specific factors that suggest infection with B. burgdorferi. Such factors include:

Proteins referred to as Osps. These proteins (referred to as Osp A through F) coat the outer surface of the B. burgdorferi spirochete and then attach to human cells after infection.
Antibodies that attack these Osps. Antibodies are the weapons of the immune system that are launched when foreign invaders (called antigens) are detected. In the case of Lyme disease, these antigens are the Osps.

Specific Tests.

The U.S. Centers for Disease Control (CDC) recommends a two-step process for Lyme disease blood tests:

ELISA and Other Initial Tests. The first tests used are either enzyme-linked immunosorbent assay (ELISA) or an indirect fluorescent antibody (IFA) test. ELISA is the immune test used most often for Lyme disease. (The IFA test is less accurate but may be used when ELISA isn't available.) ELISA measures antibodies that are directed against the B. burgdorferi spirochete. A newer variant is a rapid test (PreVue) that can provide results within an hour. Positive results from any of these tests still require confirmation with a Western blot test. Negative results do not require further testing.
Western Blot. If any of these tests is positive or uncertain, they are followed by the Western immunoblot (WB). This test is more accurate and is very helpful in confirming the diagnosis. The Western blot creates a visual graph showing bands of different colors or shading that experts use to interpret the immune response.

The CDC recommends only these tests. In 2005, the CDC warned against tests -- such as urine antigen, immunofluroescent staining, and lymphocyte transformation -- that do not have enough scientific evidence to support their use.

Accuracy of the Tests. These tests are very expensive, and none are completely accurate in either identifying Lyme or ruling it out. They should never be used to make a primary diagnosis of Lyme disease in patients who do not have obvious symptoms of the disease.

Both false positive and false negative results are common with these tests.

False positive results occur when the test suggests the presence of the disease, but the person does not actually have an active infection. This may occur in different ways:

The antibodies to the infectious organism triggering the antibodies are not the Lyme spirochetes. Other organisms that can trigger such antibodies include syphilis and relapsing fever. Dental infections may trigger a false positive response.
The patient may have been infected with Lyme disease previously and harbor antibodies to the disease.

False negative results miss the actual presence of the disease. These results are also common. (If the results are negative but Lyme disease is highly suspected, the doctor will probably prescribe antibiotics anyway.) False negative results occur for a number of reasons:

The test is taken too early in the course of Lyme disease. In such cases, the antibodies that fight the spirochete might not have reached a level that is high enough to be detected. (Only about 20 - 30% of patients can be identified using immune system tests in the first 2 - 4 weeks. By the fourth week, up to 80% of patients will have detectable antibodies.)
The patient has taken certain medications, such as steroids or certain anti-cancer drugs, which reduce the immune system's ability to produce antibodies, including those in response to Lyme disease.
There are too many infection-fighting antibodies attached to the bacteria. In this case, there are not enough loose antibodies in the blood sample to trigger a response.
The laboratory itself has set its sensitivity point too high. Some laboratories establish a standard of very high antibody levels before the test results will trigger a finding of Lyme disease. (They do this to avoid too many false-positive responses.) In so doing, however, their tests may miss the disease in patients with lower antibody levels. A related diagnostic problem concerns the possibility of missing persistent Lyme disease after antibiotic treatments, when antibody levels would be low.

All of this means that a negative blood test does not rule out a diagnosis of Lyme disease, particularly if symptoms strongly suggest its presence. Conversely, a weakly positive blood test does not prove that Lyme disease is causing the symptoms. A second blood test, taken several weeks later, may help.

The polymerase chain reaction (PCR) test detects the DNA of the bacteria that causes Lyme disease. However, it requires technical expertise and expensive equipment, and can be performed only in a few laboratories in the country. The test also has a high risk of false-positive results. Research indicates that blood or urine samples do not provide accurate results, but skin biopsies may be useful in some cases. At this point, the PCR test is reserved for certain patients with specific diagnostic problems. For most patients, standard antibody tests are preferred.

Analysis of Spinal Fluid. In patients who have neurologic symptoms, a lumbar puncture (a spinal tap) may be used to test for the bacteria in spinal fluid and may be useful for an early diagnosis of Lyme disease.

Treatment

Antibiotics are the drugs of choice for all phases of Lyme disease. In nearly all cases they can cure Lyme, even in later stages.

According to the 2006 guidelines from the Infectious Diseases Society of America (IDSA), people bitten by deer ticks should not routinely receive antibiotics to prevent the disease.

A single dose of the antibiotic doxycycline may be given in situations that meet all of the following conditions:

The tick is still attached to the patient and is positively identified as an adult or nymphal I. scapularis (the tick that carries the Lyme disease B. burgdorferi spirochete).
Doxycycline treatment can be started within 72 hours of the tick bite.
There is proof that at least 20% of ticks in that geographic area are infected with B. burgdorferi.
It is safe for the patient to receive doxycycline (this drug should not be given to pregnant women or children younger than 8 years of age).

In general, the risk of developing Lyme disease after being bitten by a tick is only 1 - 3%. However, patients who have removed attached ticks from themselves should inform their doctors. Patients who have been bitten by a tick should be monitored for up to 30 days to make sure they do not develop symptoms of Lyme disease, especially the tell-tale bull’s-eye rash. If you do develop a skin lesion or flu-like illness during this time, be sure to tell your doctor.

The early stages of Lyme disease usually involve classic bull’s-eye rash (erythema migrans) and flu-like symptoms of chills and fever, fatigue, muscle pain, and headache. In rare cases, patients develop an abnormal heartbeat (Lyme carditis).

All of these conditions are treated with 10 - 28 days of antibiotics. The exact number of days depends on the drug used, and the patient’s response to it. Antibiotics for treating Lyme disease generally include:

Doxycycline. This antibiotic is effective against both Lyme disease and human granulocytic anaplasmosis (HGA) and so is the standard antibiotic for any patient over 8 years old (except pregnant women). Doxycycline cannot be used routinely in children under 8 years old. It is a form of tetracycline and as such discolors teeth and inhibits bone growth. It can also cause birth defects, so it should not be used during pregnancy.
Either amoxicillin (one of the penicillins) or cefuroxime (Ceftin) -- a drug known as a cephalosporin -- are the alternative treatments for young children and some adults. Amoxicillin is the first choice and also probably the best antibiotic for pregnant women. Unfortunately, many people are allergic to penicillin. In addition, strains of bacteria are emerging that are resistant to penicillins.
Intravenous ceftriaxone -- another cephalosporin -- may be warranted if there are signs of infection in the central nervous system (the brain or spinal region) or heart problems.
Other types of antibiotics, such as macrolides, are not recommended for first-line therapy.

Side Effects of Antibiotics. The most common side effects of nearly all antibiotics are gastrointestinal problems, including cramps, nausea, vomiting, and diarrhea. Allergic reactions can also occur with all antibiotics, but are most common with medications derived from penicillin or sulfa. These reactions can range from mild skin rashes to rare but severe, even life-threatening, anaphylactic shock. Some drugs, including certain over-the-counter medications, interact with antibiotics. Patients should report to their doctors all medications they are taking.

Most cases of Lyme disease involve a rash and flu-like symptoms that resolve within 1 month of antibiotic treatment. However, some patients go on to develop late-stage Lyme disease, which includes Lyme arthritis and neurologic Lyme disease.

Slightly more than half of patients infected with B. burgdorferi develop Lyme arthritis. About 10 - 20 % of patients develop neurologic Lyme disease. A very small percentage of patients may develop acrodermatitis chronica atrophicans, a serious type of skin inflammation. These conditions are treated for up to 28 days with antibiotic therapy. If arthritis symptoms persist for several months, a second 2 - 4 week course of antibiotics may be recommended. Oral antibiotics (doxycycline, amoxicillin, or cefuroxime) are used for Lyme arthritis and acrodermatitis chronica atrophicans. (In rare cases, patients with arthritis may need intravenous antibiotics.)

A 2 - 4 week course of intravenous penicillin, ceftriaxone, or cefotaxime is used for treating severe cases of neurological Lyme disease. For milder cases, 2 - 4 weeks of oral doxycycline is an effective option.

In about 5% of cases, symptoms persist after treatment, a condition referred to as post-Lyme disease syndrome. The treatment of post-Lyme disease syndrome is a controversial issue. Most experts do not recommend continuing antibiotic therapy beyond 30 days. Scientific studies do not show any evidence that the benefits of long-term antibiotic treatment outweigh its risks. Long-term antibiotic treatment can lead to a serious and difficult-to-treat infection called Clostridiumdifficile, and can also cause the patient to become resistant to all types of antibiotics.

Experimental and alternative remedies are also not recommended. However, some patients may benefit from learning pain control and cognitive behavioral techniques to help them cope with and manage their symptoms.

Some people use vitamin B complex, omega-3 and omega-6 fatty acids (found in primrose oil and fish oils), and magnesium supplements (magnesium L-lactate dihydrate) to help relieve symptoms. No evidence suggests that they are beneficial. Any such therapies should be discussed with a doctor. Newsletters and Internet sites have cropped up in recent years advertising untested treatments to patients with symptoms of Lyme disease who are frustrated with traditional medical channels. Some remedies are dangerous, and most are ineffective.

In 2006, the Food and Drug Administration (FDA) warned people not to use an alternative medicine product called bismacine (also known as chromacine). This injectable product contains high amounts of bismuth, a heavy metal that can be poisonous. People who have taken bismacine have experienced heart and kidney failure, and one death has been reported. Although some people claim that bismacine can help treat Lyme disease, it is not approved for the treatment of any illness or condition.

Generally, manufacturers of herbal remedies and dietary supplements do not need FDA approval to sell their products. Just like a drug, herbs and supplements can affect the body's chemistry, and therefore have the potential to produce side effects that may be harmful. There have been a number of reported cases of serious and even lethal side effects from herbal products. Always check with your doctor before using any herbal remedies or dietary supplements.

Prevention

Everyone should avoid specific tick-infested areas, including tall grass, woods, and bushes where ticks tend to congregate. If this is not possible, people should take additional preventive measures. The U.S. Centers for Disease Control (CDC) also recommends:

Use of tick repellant.
Routine tick checks -- removal of infected ticks within 48 hours of attachment substantially reduces the likelihood of transmission.
Prompt antibiotic prevention for tick bites -- although this method is controversial, the CDC concludes that it is probably beneficial.
Removing brush and leaves -- such landscaping measures can reduce transmission rates by 50 - 90%.
Applying pesticides to yards once or twice per year, which can decrease the number of ticks by 68 - 100%

Mowing the grass regularly, clearing away leaves, and placing wood chips as a barrier around a lawn can help greatly reduce the tick population.

Permethrin for the Lawn. Insecticides can reduce tick infestation by 90%. Insecticides should be applied in late spring or early fall in a strip a few feet wide along the perimeter of the lawn where small animals are likely to enter or live.

The most commonly used insecticides are pyrethrins, which are compounds derived from the Chrysanthemum family. They are available as natural products or in synthetic forms (permethrin). They are poisons that affect the nerve system of insects. They are safe, particularly the natural products, for humans and pets. All pyrethrins are highly toxic for certain fish and slightly toxic for birds, such as mallard ducks. Some people do experience an allergic reaction to them. As with all insecticides, there is some concern about the possible consequences of long-term exposure, but to date there is no evidence of any harm.

Damminix, available in hardware stores, consists of cardboard tubes stuffed with permethrin-treated cotton. The tubes are placed where mice can find them (dense, dark brush) and collect the cotton for lining their nests. The pesticide on the cotton kills any immature ticks that are feeding on the mice. Best results are obtained with regular applications early in the spring and again in late summer. As many neighbors as possible should use it to be effective.

Other Pesticides. Other tick-killing spray pesticides that have been used include those containing diazinon, chlorpyrifos, and carbaryl. Animal studies have reported severe toxic effects associated with these chemicals. Some of these chemicals are being phased out for home use. Parents should balance the effects of a very negligible risk for a highly treatable infection versus excessive use of possibly harmful chemicals.

Fencing. Deer fencing, a wire fence about 3 - 4 yards high, or electrified fencing can be helpful, but it is costly to put up and maintain.

Ivermectin. Corn that is laced with the anti-parasite medication ivermectin (Ivomec and others) and then eaten by deer helps prevent ticks from feeding on them. Ivermectin is present in a number of products used by veterinarians to control parasites, such as heartworm. It has potential toxic effects in collie or collie mixed breeds, however.

Hiking and camping in the Northeastern woods carries a significant risk for tick bites and Lyme disease (3% in one study). Anyone out in the woods during tick season should wear protective clothing, including:

Light-colored clothing -- makes it easier to spot ticks
Long-sleeved shirts and long pants with cuffs tucked into shoes or socks
High boots, preferably rubber boots
Tick-collars for small dogs -- can be worn around a person's ankles over socks or pants

Simply washing clothes will not kill ticks. After venturing outdoors, people should run their clothes through a dryer at high temperature for a half hour. Spraying clothes with solutions containing permethrin (Permanone, Duranon, Permakill) affords additional protection. Keep in mind that these sprays should not be applied to the skin. Clothes should not be retreated with permethrin for 48 hours unless they are washed.

DEET. Most insect repellents contain the chemical DEET (N,N-diethyl-meta-toluamide), which remains the gold standard of currently available mosquito and tick repellents. DEET has been used for more than 40 years and is safe for most children when used as directed. Comparison studies suggest that DEET preparations are the most effective insect repellents now available.

Concentrations range from 4% to almost 100%. The concentration determines the duration of protection. Experts recommend that most adults and children over 12 years old use preparations containing a DEET concentration of 20 - 35% (such as Ultrathon), which provides complete protection for an average of 5 hours. (Higher DEET concentrations may be necessary for adults who are in high-risk regions for prolonged periods.)

DEET products should never be used on infants younger than 2 months. According to the Environmental Protection Agency, DEET products can safely be used on all children age 2 months and older. The EPA recommends that parents check insect repellant product labels for age restrictions.

If there is no age restriction listed, the product is safe for any age. The American Academy of Pediatrics recommends that children use concentrations of 10% or less; 30% DEET is the maximum concentration that should be used for children. In deciding what concentration is most appropriate, parents should consider the amount of time that children will be spending outside, and the risk of mosquito bites and mosquito-borne disease.

When applying DEET, take the following precautions:

Do not use on the face, and apply only enough to cover exposed skin on other areas.
Do not over apply and do not use under clothing.
Do not apply over any cuts, wounds, or irritated skin.
Parents or an adult should apply repellent to a child and not let the child apply it. They should first put DEET on their own hands and then apply it to the child. They should avoid putting DEET not only near the child's eyes and mouth but also on the hands (since children frequently touch their faces).
Wash any treated skin after going back inside.
If using a spray, apply DEET outdoors -- never indoors. Spray repellents should not be applied inside or directly on anyone's face.

Other Insect Repellent Products. In 2005, the CDC added two new mosquito repellents to its list of recommended products:

Picaridin. Picaridin, also known as KBR 3023 or Bayrepel, is an ingredient that has been used for many years in repellents sold in Europe, Latin America, and Asia. A product containing 7% picaridin is now available in the United States. Picaridin can safely be applied to young children and is also safe for women who are pregnant or breastfeeding. According to the CDC, insect repellents containing DEET or picaridin work better than other products.
Oil of lemon eucalyptus. In scientific tests, oil of lemon eucalyptus, also known as PMD, worked as well as low concentrations of DEET. However, oil of lemon eucalyptus is not recommended for children under the age of 3 years.

Self-Inspection. The tick is unlikely to transmit the infection within 3 days of the bite, but prompt removal is still important. The following tips are important for self-inspection:

Ticks responsible for Lyme disease are very small and may resemble freckles or scabs.
People spending time in tick-infested locations should inspect themselves several times a day, including at bedtime.
Check nonexposed areas, such as the back of the knee, as well as exposed areas. Someone else should check the scalp, back of the neck, and other difficult to reach areas.
Check clothing as well as skin. A tick on can be hidden in folds or creases.

Tick Removal. If an attached tick is discovered, there is no reason to panic. Do not put a hot match to the tick or try to smother it with petroleum jelly, nail polish, or other noxious substances. This only prolongs exposure time and may cause the tick to eject the Lyme organism into the body.

The safest and most effective way to remove an attached tick is:

Grasp the tick's mouth area with clean tweezers as close to the skin as possible. (Take care not to handle it with bare fingers as this can also spread infection.)
Next, pull upward with a steady even pressure. Do not twist, crush, or squeeze the body area of the tick, because this region contains the infectious organism. In fact, do not be alarmed if some of the mouth parts remain in the skin. They are not infectious.
Put the tick in a jar or container of alcohol, which will kill it. Some people lay a piece of adhesive tape to the top of the tick and fold it over, without touching the insect. Then they simply throw it away. Tape is also effective for trapping a tick that has not yet attached to the skin.
Once the tick is removed, wash the bite area with soap and water or with an antiseptic to destroy any contaminating microorganisms. Wash hands as well.

The LYMErix Vaccine. The LYMErix vaccine, previously approved, was taken off the market because of poor sales and because of problems encountered with its use. A primary limitation was that the vaccine was effective only in about 75% of cases, and the effects were not long lasting. There were also reports of arthritic and neurologic symptoms in a few vaccinated people. There is no definitive evidence, however, that the vaccine was responsible for these symptoms.

Other Vaccines. Deer ticks lay their eggs on mice and other small rodents. These eggs develop into larvae that feed on these small animals. When the larvae develop into nymphs, they seek a larger host like a deer or human. Scientists are exploring the idea of vaccinating mice and other rodents against B. burgdorferi. Inserting an oral vaccine into these animals’ food supply helps reduce the number of nymph ticks and may be a more effective preventive strategy than vaccinating humans. Recent studies suggest that vaccination of mice produces 89 - 100% protection from B. burgdorferi infection.

Since dogs, cats and even horses can get Lyme disease, inspect pets for ticks regularly. Symptoms in animals include lameness and lethargy. Dogs are much more likely to get Lyme disease than cats, but both are susceptible. In dogs, symptoms occur 2 - 5 months after a tick bite and include fever, lameness, and lack of appetite. In rare cases, Lyme disease can cause kidney damage in dogs if it is left untreated.

Preventive Products. Products containing permethrin (Bio Spot, EXspot), amitraz (Preventic), or fipronyl (Frontline) can be used safely on dogs. Not all of these products are safe in cats. Only permethrin is also effective against fleas. Some veterinarians suggest that the combination of BioSpot and Preventic is very effective. [Another product-- selamectin (Revolution) --is sold for flea and tick control, but it appears to have very limited effect against ticks.]

Pet Vaccines. Lyme disease vaccines are available for dogs, but they do not offer total protection. Veterinarians vary in their use of the vaccines.

Treatment. As with people, antibiotics almost always cure the infection in animals.

Human Granulocytic Anaplasmosis (HGA)

In addition to Lyme disease, I. scapularis deer ticks can carry other types of infections that cause disease in humans. Human granulocytic anaplasmosis (HGA) is another illness spread by the deer tick. (HGA was formerly called human granulocytic ehrlichiosis. Another type of ehrlichiosis, human monocytic ehrlichiosis, is carried by a different type of tick.)

Typical HGA symptoms appear very suddenly within 4 - 14 days of being bitten by an infected tick. Symptoms include headache, fever, chills, headache, and muscle pains. Vomiting, diarrhea, and loss of appetite are also common. Blood tests may indicate a low blood platelet count, low white blood cell count, and increased liver enzyme levels.

HGA is caused by a species of bacteria called Anaplasma phagocytophilum. A blood test can identify the presence of this bacterium.

All patients who show signs of symptoms should be treated with doxycycline to reduce the risk of complications. Another type of antibiotic, rifampin, is an alternative option for pregnant women, children younger than 8 years of age, or patients who are allergic to doxycycline. Treatment is not recommended for people who do not exhibit symptoms, even if they test positive for antibodies to A. phagocytophilum.

Babesiosis

The tick that carries Lyme disease and human granulocytic anaplasmosis (HGA) can also carry babesiosis. Babesiosis is caused by a parasite called protozoa. It has been detected in about 10% of Lyme disease patients, and has been reported in Massachusetts, New York, Connecticut, Rhode Island, New Jersey, Minnesota, Wisconsin, Georgia, California, and Washington.

When babesiosis is acquired from ticks, the infection occurs only in the summer. However, unlike in Lyme disease, blood transfusions have also been known to transmit babesiosis, so it can also occur other times of the year. The disease is still very rare, but people in tick-infested areas should be aware of it.

Symptoms of babesiosis occur 1 - 4 weeks after a tick bite and are similar to those of malaria. Most cases are very mild and nearly unrecognizable. More severe symptom may resemble those in malaria and include:

Headache
Fever and chills, with night sweats
Nausea and vomiting
Muscle aches
Anemia

In healthy people, babesiosis generally causes only mild and temporary problems, but research indicates that the infection might persist in some people and may be spreading faster than previously reported. In rare cases, it can be severe and even life-threatening, particularly in elderly people or those with chronic health problems or compromised immune systems. In such cases, the infection can cause altered mental states, anemia and other blood abnormalities, very low blood pressure, respiratory distress, and kidney insufficiency. Coinfection with Lyme disease may also increase its severity. Unfortunately, it is very difficult to diagnose.

Babesiosis is caused by a protozoon parasite, not a bacteria, so antibiotics alone won’t cure the disease. Treatment involves a two-drug combination of an anti-malaria medication and an antibiotic. The standard drug combinations are atovaquone (Mepron) plus azithromycin (Zithromax, Zmax) or clindamycin plus quinine. About 25% of patients cannot tolerate quinine. Adverse effects associated with quinine include hearing loss, tinnitus, stomach upset, diarrhea, and dizziness.

Resources

www3.niaid.nih.gov -- National Institute of Allergy and Infectious Disease
www.cdc.gov/ncidod/dvbid/lyme -- Centers for Disease Control
www.idsociety.org -- Infectious Diseases Society of America
www.aldf.com -- American Lyme Disease Foundation
www.rheumatology.org -- American College of Rheumatology
www.arthritis.org -- The Arthritis Foundation

References

Centers for Disease Control and Prevention. Lyme disease -- United States, 2003-2005. MMWR Morb Mortal Wkly Rep. 2007 Jun 15;56(23):573-6.

Feder HM Jr, Johnson BJ, O'Connell S, Shapiro ED, Steere AC, Wormser GP; Ad Hoc International Lyme Disease Group. A critical appraisal of "chronic Lyme disease." N Engl J Med. 2007 Oct 4;357(14):1422-30.

Halperin JJ, Shapiro ED, Logigian E, Belman AL, Dotevall L, Wormser GP, et al. Practice parameter: treatment of nervous system Lyme disease (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2007 Jul 3;69(1):91-102. Epub 2007 May 23.

Wormser GP, Dattwyler RJ, Shapiro ED, Halperin JJ, Steere AC, Klempner MS, et al. The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis. 2006 Nov 1;43(9):1089-134.

Review Date:
1/26/2008
Reviewed By:
Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

A.D.A.M. Copyright

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-2009 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

adam.com

Exercise

FitSugar — Wed, 08 Oct 2008 17:35:02 -0700

In This Report

Highlights
Introduction
Recommended Exercise Method...
Exercise's Effects on the H...
Exercise's Effects on Diabe...
Exercise's Effects on Bones...
Exercise's Effects on the L...
Exercise's Effects on Weigh...
Exercise's Effects on Other...
Complications
Motivation
Resources
References

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

Chronic Conditions and Exercise:

A new study found that aerobic and resistance training significantly reduced fatigue in men undergoing radiation treatments for prostate cancer. Fatigue is a common side effect of such treatments.
Doctors at the Mayo Clinic found that exercise improves the physical and emotional well-being of patients with Alzheimer's disease. The patients exercised for as little as 60 minutes each week. Doctors noted improvements in areas ranging from depression to wandering.

Exercise and Smoking:

A 2007 review of existing studies found that moderate exercise, for as little as 5 minutes, can help combat the nicotine withdrawal symptoms people experience when they try to stop smoking.

Exercise and Aging:

A 2006 report found that older and elderly adults who exercised twice a week for 4 months significantly increased their body strength, flexibility, balance, and agility. The average age of the study participants was 83.5.

Before and After Exercising:

You should do warm-up exercises for 5 - 10 minutes at the beginning of an exercise session. Low-level aerobic exercise is the best warm-up.
To cool down, you should walk slowly until your heart rate is 10 - 15 beats above your resting heart rate. Stopping too suddenly may sharply reduce blood pressure or cause muscle cramping.
You must be careful when stretching during your warm-up to avoid injuring cold muscles.

Definitions:

Aerobic exercise: Aerobic exercise forces the heart and lungs to work harder for longer periods. It builds endurance, improves blood flow throughout the body, and increases the levels of "good" cholesterol.
Resistance Training: Resistance training works muscles against a force (usually weights). It burns fat and builds muscle.

Introduction

Everyone's goal of living a long and healthy life should include a healthy diet, regular exercise, and maintaining normal weight. The combination of inactivity and eating the wrong foods is the second most common preventable cause of death in the United States (smoking is the first).

Most research on the benefits of exercise focuses on heart protection. Studies clearly show that exercise helps the heart. In addition, new studies are reporting that even people at higher risk for heart disease may lower their risk of dying from it if they exercise.

Evidence suggests that our genes evolved to favor exercise. In other words, during prehistoric times, if a person couldn't move quickly and wasn't strong, he or she died. Those who were fit survived to reproduce and pass on these "fitter" genes. Some researchers believe that with our current inactive lifestyle, these genes produce a number of bad effects, which can lead to many chronic illnesses.

The benefits of exercise include:

Improved oxygen delivery throughout the body
Improved metabolic processes - the way the body breaks down and builds necessary substances
Improved strength and endurance
Decreased body fat
Improved movement of joints and muscles
Improved sense of well-being

In addition, exercise can help change other dangerous lifestyle habits. A 2007 review of existing studies found that moderate exercise, for as little as 5 minutes at a time, can help combat the nicotine withdrawal symptoms people experience when they try to stop smoking.

No one is too young or too old to exercise. The United States Surgeon General recommends at least 30 minutes of moderate exercise, such as brisk walking, nearly every day. However, vigorous exercise carries risks that people should discuss with a doctor. You should always check with your doctor before starting a new exercise program, especially if you have any of the following risk factors:

History of smoking
Obesity
Family history of a long-term disease
A symptom you haven’t told your doctor about
Chest pain
Shortness of breath
Heart palpitations
Blood clots
Infections
Fever
Unexplained weight loss
Foot or ankle sores that won’t heal
Joint swelling
Pain or trouble walking after a fall
Eye injury or eye surgery
Hernia
Hip surgery

Fifty percent of all people who begin a vigorous training program drop out within a year. The key to reaching and maintaining physical fitness is to find activities that are exciting, challenging, and satisfying.

Recommended Exercise Methods

A few simple rules are helpful as you develop your own routine.

Don't eat for 2 hours before vigorous exercise.
Drink plenty of fluids before, during, and after a workout.
Adjust your activity level according to the weather, and reduce it when you are fatigued or ill.
When exercising, listen to the body's warning symptoms, and consult a doctor if exercise causes chest pain, irregular heartbeat, undue fatigue, nausea, unexpected breathlessness, or light-headedness.

Heart rate is the standard guide for determining aerobic exercise intensity. It can be determined by counting one's own pulse or with the use of a heart rate monitor. To feel your own pulse, press the first two fingers of one hand gently down on the inside of the wrist or under the jaw on the right or left side of the front of the neck. You should feel a faint pounding as blood passes through the artery. Each pounding is a beat.

Click the icon to see how to take a radial pulse

Click the icon to see how to take a carotid pulse.

There are different types of heart rates.

Resting heart rate. The average heart rate for a person at rest is 60 - 80 beats per minute. It is usually lower for people who are physically fit, and often rises as you get older. You can determine your resting heart rate by counting how many times your heart beats in one minute. The best time to do this is in the morning after a good night’s sleep before you get out of bed.

Maximum heart rate. To determine your own maximum heart rate per minute subtract your age from 220. For example, if you are 45, you would calculate your maximum heart rate as follows: 220 - 45= 175.

Target heart rate. Your target rate is 50 - 75% of your maximum heart rate. You should measure your pulse off and on while your exercise to make sure you stay within this range. After about 6 months of regular exercise, you may be able to increase your target heart rate to 85% (but only if you can comfortably do so).

Certain heart medications may lower your maximum and target heart rates. Always check with your doctor before starting an exercise program.

Note: Swimmers should use a heart rate target of 75% of the maximum and then subtract 12 beats per minute. The reason for this is that swimming will not raise the heart rate quite as much as other sports because of the so-called "diving reflex," which causes the heart to slow down automatically when the body is immersed in water.


Age	Low	High
	(50% max.)	(75% max.)
20	100	150
30	95	142
40	90	135
50	85	127
60	80	120
Source: American Heart Association

VO2 Max. Serious exercisers may use a VO2 max calculation, which measures the amount of oxygen consumed during intensive, all-out exercise. The most accurate testing method uses computers, but anyone can estimate V02 without instrumentation (with an accuracy of about 95%):

After running at top pace for 15 minutes, round off the distance run to the nearest 25 meters.
Divide that number by 15.
Subtract 133.
Multiply the total by 0.172, then add 33.3.

Olympic and professional athletes train for VO2 max levels above 80. But for the average person interested in fitness, a VO2 max equaling between 50 and 80 is considered an excellent score for overall fitness.

Click the icon to see an image on exercise and heart rate.

Warming up and cooling down are important parts of every exercise routine. They help the body make the transition from rest to activity and back again, and can help prevent soreness or injury, especially in older people.

Warm-up exercises should be practiced for 5 - 10 minutes at the beginning of an exercise session. Older people need a longer period to warm up their muscles. Low-level aerobic exercise such as brisk walking, swinging the arms, or jogging in place, is the best approach.
To cool down, you should walk slowly until the heart rate is 10 - 15 beats above your resting heart rate. Stopping too suddenly can sharply reduce blood pressure, and is dangerous for older people. It may also cause muscle cramping.
Stretching may be appropriate for the cooling down period, but it must be done carefully for warming up because it can injure cold muscles. (There is no clear evidence, however, that stretching reduces muscle injuries.)

Warming up before exercise and cooling down after is just as important as the exercise itself. By properly warming up the muscles and joints with low-level aerobic movement for 5 - 10 minutes, one may avoid injury and build endurance over time. Cooling down after exercise by walking slowly, then stretching muscles, may also prevent strains and blood pressure fluctuation.

For most people, exercise may be divided into three general categories:

Aerobic or endurance
Strength or resistance
Flexibility

A balanced program should include all three. Speed training is also a major category, but generally only competitive athletes practice it.

Benefits of Aerobic Exercise. Regular aerobic exercise provides the following benefits:

Builds endurance
Keeps the heart pumping at a steady and high rate for a long time
Boosts HDL ("good") cholesterol levels
Helps control blood pressure
Strengthens the bones in the spine
Helps maintain normal weight
Improves one's sense of well-being

Types of Aerobic Exercise. Aerobic exercise is usually categorized as high or low impact. Examples of each include the following:

Low- to moderate-impact exercises: Walking, swimming, stair climbing, step classes, rowing, and cross-country skiing. Nearly anyone in reasonable health can engage in some low- to moderate-impact exercise. Brisk walking burns as many calories as jogging for the same distance and poses less risk for injury to muscle and bone.
High-impact exercises: Running, dance exercise, tennis, racquetball, squash. High-impact exercises should be performed no more than every other day, and less often for those who are overweight, elderly, out of condition, or have an injury or other medical problem that would rule out high-impact.

Click the icon to see an image of aerobic exercise.

Aerobic Regimens. As little as one hour a week of aerobic exercises is helpful, but 3 - 4 hours per week are best. Some research indicates that simply walking briskly for 3 or more hours a week reduces the risk for coronary heart disease by 65%. In general, the following guidelines are useful for most individuals:

For most healthy young adults, the best approach is a mix of low- and higher-impact exercise. Two weekly workouts will maintain fitness, but three to five sessions a week are better.
People who are out of shape or elderly should start aerobic training gradually. For example, they may start with 5 - 10 minutes of low-impact aerobic activity every other day and build toward a goal of 30 minutes per day, three to seven times a week. (For heart protection, frequency of exercises may be more important than duration.)
Swimming is an ideal exercise for many elderly and certain people with physical limitations, including pregnant women, individuals with muscle, joint, or bone problems, and those who suffer from exercise-induced asthma.
People who seek to lose weight should aim for six to seven low-impact workouts a week.

One way of gauging the optimal intensity of exercise is to aim for a "talking pace," which is enough to work up a sweat and still be able to converse with a friend without gasping for breath. As fitness increases, the "talking pace" will become faster and faster.

Shoes. All that's really necessary for a workout is a good pair of shoes that are made well and fit well. They should be broken in, but not worn down. They should support the ankle and provide cushioning for impact sports such as running or aerobic dancing. Airing out the shoes and feet after exercising reduces chances for skin conditions such as athlete's foot.

Clothing. Comfort and safety are the key words for workout clothing. For outdoor nighttime exercise, a reflective vest and light-colored clothing must be worn. Bikers, roller bladers, and equestrians should always wear safety devices such as helmets, wrist guards, and knee and elbow pads. Goggles are mandatory for indoor racquet sports. For vigorous athletic activities, such as football, ankle braces may be more effective than tape in preventing ankle injuries.

Aerobic-Exercise Equipment. Home aerobic exercise machines can be adapted to any fitness level and used day or night. Before investing in any exercise machine, however, it is wise to first test it at a gym. In addition, initial supervised training when using these machines can reduce the risk of injury that might occur with self-instruction.

Very inexpensive exercise machines tend to be flimsy and hard to adjust, but many sturdy machines are available at moderate prices. The higher-end models may utilize computers to record calories burned, speed, and mileage. While their readouts may provide motivation and gauge the intensity of a workout, however, they are not always accurate.

The following are a few observations on specific equipment:

A good floor mat is important to provide cushioning for all home exercises.
A simple jump rope improves aerobic endurance for people who are able to perform high-impact exercise. Jumping rope should be done on a floor mat plus a surface that has some give to avoid joint injury.
For burning calories, the treadmill has been ranked best, followed by stair climbers, the rowing machine, cross-country ski machine, and stationary bicycle. (Elliptical trainers, however, may be even better than treadmills for increasing heart rate, calorie expenditure, and oxygen consumption.)
Stationary bikes condition leg muscles and are fairly economical and easy to use safely. The pedals should turn smoothly, the seat height should adjust easily, and the bike's computer should be able to adjust intensity.
Stair machines also condition leg muscles. They offer very intense, low-impact workouts and may be as effective as running with less chance of injury.
Rowing and cross-country ski machines exercise both the upper and lower body.


Aerobic dancing	Sufficient cushioning to absorb shock and pressure that are many times greater than ordinary walking. Arches that maintain side-to-side stability. Thick upper leather support. Toe-box. Orthotics may be required for people with ankles that over-turn inward or outward. Soles should allow for twisting and turning.
Cycling	Rigid support across the arch to prevent collapse during pedaling. Heel lift. Cross-training or combination hiking/cycling shoes may be sufficient for casual bikers. Toe clips or specially designed shoe cleats for serious cyclers. In some cases, orthotics may be needed to control arch and heel and balance forefoot.
Running	Sufficient cushioning to absorb shock and pressure. Fully bendable at the ball of the foot. Sufficient traction on sole to prevent slipping. Consider insoles or orthotics with arch support for problem feet.
Tennis	Allow side-to-side sliding. Low-traction soles. Snug fitting heels with cushioning. Padded toe box with adequate depth. Soft-support arch.
Walking	Lightweight. Breathable upper material (leather or mesh). Wide enough to accommodate ball of the foot. Firm padded heel counter that does not bite into heel or touch ankle bone. Low heel close to ground for stability. Good arch support. Front provides support and flexibility.

Benefits of Strength Exercise. While aerobic exercise increases endurance and helps the heart, it does not build upper body strength or tone muscles. Strength-training exercises provide the following benefits:

Build muscle strength while burning fat
Help maintain bone density
Improve digestion

It is also associated with a lower risk for heart disease, possibly because it lowers LDL (the so-called "bad") cholesterol levels.

Click the icon to see an image of cholesterol.

Strength exercise is beneficial for everyone, even people in their 90s. It is the only form of exercise that can slow and even reverse the decline in muscle mass, bone density, and strength that occurs with aging. Please note: People at risk for cardiovascular disease should not perform strength exercises without checking with a doctor.

Types of Muscle Contractions. There are three types of muscle contractions involved in strength training:

Isometric contractions do not change the length of the muscle. An example is pushing against a wall.
Concentric contractions shorten muscles. An example is the "up" phase of a bicep curl.
Eccentric contractions lengthen muscles. An example is the "down" phase as weights are lowered.

Click the icon to see an image of isometric exercise.

Strength-Training Regimens. Strength training involves intense and short-duration activities. For beginners, adding 10 - 20 minutes of modest strength training two to three times a week may be appropriate. The following are some guidelines for starting a strength regimen:

The sequence of a strength training session should begin with training large muscles and multiple joints at higher intensity and end with small muscle and single joint exercises at lower intensities.
Both shortening and lengthening muscle actions should be performed. Emphasizing the movements that lengthen muscles is of increasing interest. This approach involves slowing and increasing the duration of these "down" movements. It appears to significantly increase blood flow, and some evidence suggests it may achieve stronger muscles more quickly. It may also improve heart function compared to standard movements. Exercises that lengthen muscles may be particularly beneficial for older people and some people with chronic health problems. This type of training increases the risk for muscle soreness and injury, however, and this approach is still controversial.
Strength training involves moving specific muscles in the same pattern against a resisting force (such as a weight) for a preset number of times. This is called a repetition. Students should first choose a weight that is about half of what would require a maximum effort in one repetition. In other words, if it would take maximum effort to do a single repetition with a 10-pound dumbbell, the person would start with a five-pound dumbbell. In the beginning, most people can start with one set of 8 - 15 repetitions per muscle group with low weights. As individuals are able to perform one or two repetitions over their routine, weights can be increased by 2 - 10%.
Breathe slowly and rhythmically. Exhale as the movement begins. Inhale when returning to the starting point.
The first half of each repetition typically lasts 2 - 3 seconds. The return to the original position lasts 4 seconds.
An alternative technique called "super slow" training stretches out one repetition to a 14-second count. This method places far more stress on the muscle group, so fewer repetitions are needed. A full week of recovery is required before repeating this workout. The goal is to initiate changes in the muscles so that the body continues to burn calories after the exercise. Some people report dramatic results from this approach, but scientific proof of these claims is not available. It is a very tedious workout, and people have a hard time sticking with it. People with high blood pressure should not use this approach.
Joints should be moved rhythmically through their full range of motion during a repetition. Do not lock up the joint while exercising it.
For maximum benefit, one should allow 48 hours between workouts for full muscle recovery.

Click the icon to see the proper way to breathe during exercise.

Strength-Training Equipment. Unlike aerobic exercise, strength training almost always requires some equipment. Strength-training equipment does not, however, have to cost anything.

Any heavy object that can be held in the hand, such as a plastic bottle filled with sand or water, can serve as a weight.
Dumbbells (1 - 10 pounds) and resistance bands are inexpensive, portable, and effective.
Wearable weights help strengthen and tone the upper body.
Ankle weights strengthen and tone muscles in the lower body. Wearable ankle weights should not be worn during high-impact aerobics or jumping.
Hand grips strengthen arms and are good for relieving tension.
A pull-up bar can be mounted in a doorway for chin-ups and pull-ups.

More elaborate and expensive home equipment for working body muscles is also available, costing from $100 to over $1,000. No one should purchase or use strength-training equipment without instruction from a professional.

Benefits of Flexibility Training. Flexibility training uses stretching exercises. Many stretching exercises are particularly beneficial for the back. In general, flexibility training provides the following benefits:

Prevents cramps, stiffness, and injuries
Improves joint and muscle movement (improved range of motion)

Certain flexibility practices, such as yoga and tai chi, also involve meditation and breathing techniques that reduce stress. Such practices appear to have many health and mental benefits. They may be very suitable and highly beneficial for older people, and for patients with certain chronic diseases.

Click the icon to see an image of flexibility exercise.

Flexibility Training Regiments. Doctors recommend performing stretching exercises for 10 to 12 minutes at least three times a week. The following are some general guidelines:

When stretching, exhale and extend the muscles to the point of tension, not pain, and hold for 20 - 60 seconds. (Beginners may need to start with a 5- to 10-second stretch.)
Breathe evenly and constantly while holding the stretch.
Inhale when returning to a relaxed position. Holding your breath defeats the purpose; it causes muscle contraction and raises blood pressure.
When doing stretches that involve the back, relax the spine to keep the lower back flush with the mat, and to work only the muscles required for changing position (often these are only the abdominal muscles).

Studies continue to show that it is never too late to start exercising. A report published in the February 2006 Journal of Aging and Health found that elderly adults who exercised twice a week for four months significantly increased their body strength, flexibility, balance, and agility. The exercise program included walking and lifting weights. The average age of the study participants was 83.5. The study adds further evidence that even small improvements in physical fitness and activity can prolong life and independent living.

Still, about half of Americans over 60 describe themselves as sedentary (inactive). According to a 2004 report by the Centers for Disease Control and Prevention, approximately 12% of people aged 65 - 75 years and 10% of people aged 75 years or older meet current recommendations for strength training.

The following tips for exercising may be helpful:

Any older person should have a complete physical and medical examination, as well as professional instruction, before starting an exercise program.
Start low and go slow. For sedentary, older people, one or more of the following programs may be helpful and safe: Low-impact aerobics, gait (step) training, balance exercises, tai chi, self-paced walking, and lower legs resistance training, using elastic tubing or ankle weights. Even in the nursing home, programs aimed at improving strength, balance, gait, and flexibility have significant benefits.
Strength training assumes even more importance as one ages, because after age 30 everyone undergoes a slow process of muscular erosion. The effect can be reduced or even reversed by adding resistance training to an exercise program. As little as one day a week of resistance training improves overall strength and agility. Strength training also improves heart and blood vessel health.
Power training, which aims for the fastest rate at which a muscle or muscle group can perform work, may be particularly helpful for older women in strengthening muscles and preventing falls.
Flexibility exercises promote healthy muscle growth and help reduce the stiffness and loss of balance that accompanies aging.
Chair exercises may be performed by people who are unable to walk.
Older women are at risk for incontinence accidents during exercise. This can be reduced or prevented by performing Kegel exercises, limiting fluids (without risking dehydration), going to the bathroom frequently, and using leakage prevention pads or insertable devices.

Exercise's Effects on the Heart

Inactivity is one of the major risk factors for heart disease. However, exercise helps improve heart health, and can even reverse some heart disease risk factors.

Like all muscles, the heart becomes stronger as a result of exercise, so it can pump more blood through the body with every beat and continue working at maximum level, if need be, with less strain. The resting heart rate of those who exercise is also slower, because less effort is needed to pump blood.

A person who exercises often and vigorously has the lowest risk for heart disease, but any amount of exercise is beneficial. Studies consistently find that light-to-moderate exercise is even beneficial in people with existing heart disease. Note, however, that anyone with heart disease should seek medical advice before beginning a workout program.

The heart is a large muscular organ that pumps blood throughout the body. Valves inside the heart open and close. This controls how much blood enters or leaves the heart.

Exercise has a number of effects that benefit the heart and circulation (blood flow throughout the body). These benefits include improving cholesterol and fat levels, reducing inflammation in the arteries, assisting weight loss programs, and helping to keep blood vessels flexible and open. Studies continue to show that physical activity and avoiding high-fat foods are the two most successful means of reaching and maintaining heart-healthy levels of fitness and weight.

The American Heart Association recommends that individuals perform moderately-intense exercise for at least 30 minutes on most days of the week. This recommendation supports similar exercise guidelines issued by the Centers for Disease Control and Prevention, and the American College of Sports Medicine.

Coronary Artery Disease. People who maintain an active lifestyle have a 45% lower risk of developing heart disease than do sedentary people. Experts have been attempting to define how much exercise is needed to produce heart benefits. In 2002, a well-conducted study on overweight adults confirmed previous research that reported beneficial changes in cholesterol and lipid levels, including lower LDL levels (bad cholesterol), even when people performed low amounts of moderate- or high-intensity exercise such as walking or jogging 12 miles a week. However, more intense exercise is required to significantly change cholesterol levels, notably increasing HDL (good cholesterol). An example of this kind of program would be jogging about 20 miles a week. Such benefits in the study occurred even with very modest weight loss, suggesting that overweight people who have trouble losing pounds can still achieve considerable heart benefits by exercising.

Some studies suggest that for the greatest heart protection, it is not the duration of a single exercise session that counts but the total daily amount of energy expended. Therefore, the best way to exercise may be in multiple short bouts of intense exercise, which can be particularly helpful for older people.

Resistance (weight) training has also been associated with heart protection. It may offer a complementary benefit to aerobics by reducing LDL levels. Exercises that train and strengthen the chest muscles may prove to be very important for patients with angina.

Effects of Exercise on Blood Pressure. Regular exercise helps keep arteries elastic (flexible), even in older people. This, in turn, ensures good blood flow and normal blood pressure. Sedentary people have a 35% greater risk of developing high blood pressure than athletes do.

Click the icon to see the risks associated with untreated hypertension.

It should be noted that high-intensity exercise may not lower blood pressure as effectively as moderate-intensity exercise. In one study, moderate exercise (jogging 2 miles a day) controlled high blood pressure so well that more than half the patients who had been taking drugs for the condition were able to discontinue their medication. However, a small study published in 2005 suggests that moderate exercise does not have a significant impact on systolic blood pressure (the top number) in older adults. While those who exercised did have notable drops in both the top and lower (diastolic) blood pressure levels, the only statistically significant change was the decrease in the lower number.

Experts recommend at least 30 minutes of exercise on most -- if not all -- days. Studies show that yoga and tai chi, an ancient Chinese exercise involving slow, relaxing movements, may lower blood pressure almost as well as moderate-intensity aerobic exercises.

Click the icon to see an image of someone practicing yoga.

Anyone with existing high blood pressure should discuss an exercise program with their doctor. Before starting to exercise, people with moderate-to-severe high blood pressure should lower their pressure, and be able to control it with medications. Everyone, and especially people with high blood pressure, should breathe as normally as possible through each exercise. Holding the breath increases blood pressure.

Effects of Exercise on Heart Failure. Traditionally, heart failure patients have been discouraged from exercising. Now, exercise performed under medical supervision is proving to be helpful for select patients with stable heart failure.

Studies continue to report benefits from exercise training. In one study, heart failure patients as old as 91 years old increased their oxygen use significantly, after 6 months of supervised treadmill and stationary bicycle exercises.
Progressive resistance training may be particularly useful for heart failure patients, since it strengthens muscles, which commonly weaken in this disorder. Even simply performing daily handgrip exercises can improve blood flow through the arteries.

Experts warn, however, that exercise is not appropriate for all heart failure patients.

All stroke survivors should have a pre-exercise evaluation done by their doctor before starting an exercise program.

The effects of exercise on stroke are less established than those on heart disease, but most studies show benefits. The following are some examples:

According to one major analysis, men cut their risk for stroke in half if their exercise program was roughly equivalent to about an hour of brisk daily walking 5 days a week. In the same study, exercise that involved recreation was more protective against stroke than exercise routines consisting simply of walking or climbing.
A 2000 study of women also found substantial protection from stroke in brisk walking or striding (rather than casual walking).

Anyone with heart disease or risk factors for developing heart disease or stroke should seek medical advice before beginning a workout program. Patients with heart disease can nearly always exercise safely as long as they work out under medical supervision. Still, it is often difficult for a doctor to predict health problems that might arise as the result of an exercise program. At-risk individuals should be very aware of any symptoms warning of harmful complications while they exercise.

Some experts believe that anyone over 40 years old, whether or not they are at risk for heart disease, should have a complete physical examination before starting or intensifying an exercise program. Some doctors use a questionnaire for people over 40 to help determine whether they require such an examination. The questions they use are as follows:

Has any doctor previously recommended medically supervised activity because of a heart condition?
Is chest pain brought on by physical activity?
Has chest pain occurred during the previous month?
Does the person faint or fall over from dizziness?
Is bone or joint pain intensified by exercise?
Has medication been prescribed for hypertension (high blood pressure) or heart problems?
Is the person aware of or has a doctor suggested any physical reason for not exercising without medical supervision?

Those who answer "yes" to any of the above questions should have a complete medical examination before developing an exercise program.

Stress Test. A stress test helps determine the risk for a heart problem resulting from exercise. Anyone with a heart condition or history of heart disease should have a stress test before starting an exercise program. Experts currently also recommend this test before a vigorous exercise program for older persons who are sedentary, even in the absence of known or suspected heart disease. The test is expensive, however, and some experts believe that it may not be necessary for many older people with no evident health problems or risk factors.

A small percentage of heart attacks occur after heavy physical work.

High-Risk Individuals. In general, the following people should avoid intense exercise or start it only with careful monitoring:

People who have certain medical conditions: These conditions include uncontrolled diabetes, uncontrolled seizures, uncontrolled high blood pressure, a heart attack within the previous 6 months, heart failure, unstable angina, significant aortic valve disease, or aortic aneurysm.
People with moderate-to-severe hypertension: Experts generally recommend that moderate or severe high blood pressure (systolic blood pressure over 160 mm Hg or diastolic (bottom number) pressure over 100 mm Hg) should be brought to lower levels before a person starts a vigorous exercise program.
Sedentary people should be cautious. One major study found that sedentary people who throw themselves into a grueling workout significantly increase their risk of heart attack.
Episodes of exercise-related sudden death in young people are rare but of great concern. Some are preceded by fainting, which is due to a sudden and severe drop in blood pressure. It should be noted that fainting is relatively common in athletes, and is dangerous only in people with existing heart conditions. Young people with genetic or congenital (present at birth) heart disorders should avoid intensive competitive sports.
Anabolic steroids or products containing ephedra have been associated with cases of stroke, heart attack, and even death.

The risk for heart attack from exercise should be kept in perspective, however. Some form of exercise, carefully personalized, has benefits for most of the individuals mentioned above. In many cases, particularly when the only risk factors are a sedentary lifestyle and older age, exercise can often be increased over time until it is intense.

Hazardous Activities for High-Risk Individuals. The following activities may pose particular dangers for high-risk individuals:

Intense workouts (snow shoveling, slow jogging, speed walking, tennis, heavy lifting, heavy gardening) may be particularly hazardous for people with risk factors for heart disease, especially older people. They tend to stress the heart, raise blood pressure for a brief period, and may cause spasms in the arteries leading to the heart. (See image: Coronary Artery Spasm)
Some studies suggest that competitive sports, which couple intense activity with aggressive emotions, are more likely to trigger a heart attack than other forms of exercise.

Listening for Warning Signs. It should be noted that according to one study, at least 40% of young men who die suddenly during a workout have previously experienced, and ignored, warning signs of heart disease. In addition to avoiding risky activities, the best preventive tactic is simply to listen to the body and seek medical help at the first sign of symptoms during or following exercise. These symptoms include the following:

Irregular heartbeat
Shortness of breath
Chest pain

Click the icon to see an image of a coronary artery spasm.

Click the icon to see an image of stable angina.

Exercise's Effects on Diabetes

Moderate aerobic exercise can lower your risk for type 2 diabetes. An important study found that adults who worked out 2 and 1/2 hours a week cut their risk by 58%.

Exercise has positive benefits for those who have diabetes. It can lower blood sugar, improve insulin sensitivity, and strengthen the heart. Strength training, which increases muscle and reduces fat, may be particularly helpful for people with diabetes, but more evidence is needed to confirm this theory. One study reported that yoga helped patients with type 2 diabetes reduce their need for oral medications.

In 2005, researchers found that people with type 2 diabetes who walked a minimum of 3 miles every day were in better health, and had lower medical expenses, after 2 years of such exercise. Those who remained sedentary for that time period experienced a decline in their overall health and higher health care-related expenses. Study participants who worked out for an average of 38 minutes per day lowered their blood pressure, cholesterol ,and A1C levels (glucose concentration over time). These participants also had lower heart disease risk, even if they didn't lose weight. The increase in the study participants' activity equaled about 2,200 extra steps a day. The findings were reported in the journal Diabetes Care.

An earlier study found that healthy lifestyle changes may work better than the prescription medication metformin (Glucophage), when it comes to preventing metabolic syndrome. Metabolic syndrome is a combination of risk factors including abdominal obesity, insulin resistance, high triglycerides, and hypertension.

The following are precautions for all people with diabetes, whether type 1 or 2:

Because people with diabetes are at higher than average risk for heart disease, they should always check with their doctors before starting a demanding exercise program. For best and fastest results, frequent high-intensity (not high-impact) exercises are best for people who are cleared by their doctor. For people who have been sedentary, or have other medical problems, lower-intensity exercises are recommended, using programs the patients designed with their doctors.
Strenuous strength training or high-impact exercise is not recommended for people with uncontrolled diabetes. Such exercises can strain weakened blood vessels in the eyes of patients with retinopathy (a common diabetic complication). High-impact exercise may also injure blood vessels in the feet.

Patients who are taking medications that lower blood glucose, particularly insulin, should take special precautions before starting a workout program.

Glucose levels swing dramatically during exercise. People with diabetes should monitor their levels carefully before, during, and after workouts.
Patients should probably avoid exercise if glucose levels are above 300 mg/dL or under 100 mg/dL.
To avoid hypoglycemia (low blood sugar), people with diabetes should inject insulin in sites away from the muscles they use the most during exercise.
People with diabetes should drink plenty of fluids. Before exercising, they should avoid alcohol, which increases the risk of hypoglycemia.
Insulin-dependent athletes may need to decrease insulin doses, or take in more carbohydrates, prior to exercise. However, they may need to take an extra dose of insulin after exercise. Stress hormones released during exercise may increase blood glucose level (in people without diabetes, insulin is released to control this increase). People with diabetes must regularly test their blood sugar, and take any medications as instructed by their doctor.

A person with diabetes must regularly check their blood sugar (glucose) level.

Exercise's Effects on Bones and Muscles

Exercise is critical for strong muscles and bones. Muscle strength declines as people age, but studies report that when people exercise they are stronger and leaner than others in their age group.

Exercise helps kids lower their risk of chronic pain in the future. Research has shown that it helps them prevent back and neck pain. The more flexible men are as teenagers, the lower their risk of neck tension in the future, according to a study published in the February 2006 British Journal of Sports Medicine. The same report found that women who had the greatest endurance strength as teenagers had a lower risk of tension neck than those with lower teenager endurance strength. However, men with the greatest endurance strength had higher rates of knee injuries later on.

Joints are complex structures. They are designed to bear weight and move the body. Above the knee is the femur (thigh bone). Below the knee is the tibia (shin bone) and fibula. The kneecap is also called the patella. It rides on top of the lower portion of the femur and the top portion of the tibia. The muscles and ligaments connect these bones and the space between them is cushioned by fluid-filled capsules (synovia) and cartilage. When you exercise, the muscles pull on the bones, strengthening them. The range of motion of a joint represents how far it can be flexed (bent) and extended (stretched).

Joints require motion to stay healthy. Long periods of inactivity cause the arthritic joint to stiffen and the adjoining tissue to weaken. A moderate exercise program that includes low-impact aerobics, power, and strength training has benefits for osteoarthritic patients, even if exercise does not slow down the disease progression. Many patients who start an exercise program report less disability and pain. They are also better able to perform daily chores, and remain independent longer than their inactive peers. Older patients and those with medical problems should always check with their doctor before starting an exercise program.

Click the icon to see an image of osteoporosis.

The following are useful exercises for osteoarthritis patients:

Strengthening exercises builds muscle strength. Some experts encourage patients to emphasize strengthening leg muscles as a first treatment step, even before using pain relievers. They fear that patients who rely on painkilling drugs may overuse knees, which do not have strong enough muscle tissue to protect the joints from further damage. Strengthening the thigh muscles is certainly protective for those who have not developed osteoarthritis.
Range-of-motion exercises increase the amount of movement in a joint and muscle. The best examples are yoga and tai chi, which focus on flexibility, balance, and proper breathing. In one 2001 study, older adults who practiced the gentle movement, breathing, and meditation exercises of tai chi for 10 weeks reported less pain than their peers who did not learn the technique.
Low-impact aerobic workouts help stabilize and support the joints. Cycling and walking are beneficial, and swimming or exercising in water is highly recommended for people with arthritis. Patients with arthritis should avoid high-impact sports, such as jogging, tennis, and racquetball.
Some researchers are now focusing on "power" training, which involves improving the muscle's ability to move more rapidly against resisting forces, such as gravity. For example, such training helps people stand up or climb stairs more quickly. Muscle power declines more rapidly than muscle strength, and may be particularly important in older people.

Exercise is very important for slowing the progression of osteoporosis, and extremely important for reducing the risk of falling, which causes fractures. Falls are one of the leading causes of death in people over the age of 65. Exercise helps build balance and flexibility, which reduces the risk of falling.

Specific exercises may be especially helpful for reducing the risk of fractures:

Weight-bearing exercise is very beneficial for bones in people of all ages, even older people. This approach applies tension to muscle and bone, and the body responds to this stress by increasing bone density, in young adults by as much as 2 - 8% a year. Careful weight training can also be very beneficial for elderly people, particularly women. In addition to improving bone density, weight-bearing exercise reduces the risk of fractures by improving muscle strength and balance, thus helping to prevent falls.
Regular brisk long walks improve bone density and mobility. In one 2002 study, for example, older women reduced their risk of hip fracture by over 40% by working out just four hours a week.
Exercises specifically targeted to strengthen the back can be beneficial in improving posture, and may even reduce kyphosis (hunchback) in people with osteoporosis.
Low-impact exercises, particularly yoga and tai chi, which improve balance and strength, have been found to decrease the risk of falling. In one study, tai chi reduced this risk by almost half.

Click the icon to see an image of the bone-building exercise.

Note on Female Athlete Triad. Some young female athletes who exercise very intensely, and are subject to intense pressure to remain thin, are at risk for the female athlete triad. This syndrome is a combination of three disorders -- an eating disorder, loss of menstrual periods, and osteoporosis.

People who do not exercise regularly face an increased risk for low back pain, especially during times when they suddenly have to perform stressful, unfamiliar activities. These activities may include shoveling, digging, or moving heavy items. Although no definitive studies have been done to prove the relationship between lack of exercise and low back pain, sedentary living is probably a primary nonmedical cause contributing to this condition.

Lack of exercise leads to the following conditions that may threaten the back:

Muscle inflexibility can restrict the back's ability to move, rotate, and bend.
Weak stomach muscles can increase the strain on the back and can cause an abnormal tilt of the pelvis (hip bones).
Weak back muscles may increase the load on the spine and the risk of disk compression.
Obesity puts more weight on the spine and increases pressure on the vertebrae and disks. Studies report only a weak association between obesity and low back pain, however.

Benefits for Chronic Back Pain. People in with sudden and severe back pain should not exercise. Exercise plays a very beneficial role in relieving chronic back pain, however. In one study, patients with back pain lasting for an average of 18 months were assigned eight 1-hour exercise sessions over 4 weeks. They showed greater improvement in nearly every area, including reduced pain, compared to patients who did not exercise.

Exercise should be considered as part of a broader program to return to normal home, work, and social activities. In this way, the positive benefits of exercise not only affect strength and flexibility but they also alter and improve the patients' attitudes toward their disability and pain.

Repetition is the key to increasing flexibility, building endurance, and strengthening the specific muscles needed to support the spine. Some exercise programs used for prevention or treatment of chronic low back pain include the following:

Low-impact Aerobic Exercises: Low-impact aerobic exercises, such as swimming, bicycling, and walking, can strengthen muscles in the abdomen and back without over-straining the back. Programs that use strengthening exercises while swimming may be a particularly beneficial approach for many patients with back pain. In one study, for example, pregnant women who engaged in a water gymnastics program had less back pain, and were able to continue working longer.
Lumbar Extension Strength Training: Exercises called lumbar extension strength training are proving to be effective. Generally, these exercises attempt to strengthen the abdomen, and improve lower back mobility, strength, and endurance. They also enhance flexibility in the hip and hamstring muscles, and in the tendons at the back of the thigh.
Yoga, Tai Chi, and Chi Kung: These exercises combine low-impact physical movements and meditation. They are based on principles of disciplining the mind to achieve a physical and mental balance, and can be very helpful in preventing recurrences of low back pain. In one study of Pilates, an exercise practice that uses yoga principles, the exercises were helpful in a woman with progressive and disabling severe low back pain resulting from early scoliosis. This approach deserves further research.
Flexibility Exercises: Whether flexibility exercises alone offer any significant benefit for chronic back pain is uncertain. One study suggested that any benefits derived from flexibility exercises are lost unless the exercise programs are sustained.
Retraining Deep Muscles: Studies are finding a link between low back pain and poor motor control of deep muscles in the back and trunk. According to these studies, contraction exercises specifically designed to retrain these muscles may be effective for patients with both acute and chronic pain.

It is important for any person who has low back pain to have an exercise program guided by professionals who understand the limitations and special needs of back pain and who can address individual health conditions. One study indicated that patients who planned their own exercise did worse than those in physical therapy or doctor-directed programs.

Hazardous Effects on the Back. Improper or excessive exercise can also cause back pain.

Exercise's Effects on the Lungs

Patients with chronic lung problems have difficulty exercising. Shortness of breath is a major limitation in most patients, but in about a third, muscle fatigue is an even greater problem. Although exercise does not improve lung function, training helps many patients with chronic lung disease by strengthening their limb muscles, thus improving endurance and reducing breathlessness.

In people who already have colds, exercise has no effect on the illness' severity or duration. People should avoid strenuous physical activity when they have fevers, muscle aches, or other symptoms of a widespread viral illnesses.

Long-term exercise may help control asthma and reduce hospitalization. One 2000 study found that aerobic exercise improves breathing capacity and function in patients with mild asthma. People with asthma who enjoy running should probably choose an indoor track, to avoid pollutants. Swimming is particularly excellent for people with asthma. Yoga practice, which uses both stretching, breathing, chest expansion, and meditation techniques may have specific benefits that include stress reduction as well as airway opening. One study reported that two thirds of patients who practiced yoga regularly were able to reduce or eliminate their asthma medications.

Exercise-Induced Asthma. About 40 - 90% of asthma cases are exercise-induced asthma (EIA), in which exercise triggers coughing, wheezing, or shortness of breath. It occurs most often in children and young adults and during intense exercise in cold dry air. EIA is triggered only by exercise. Unlike allergic asthma, there is no long-term increase in airway activity. People who only have EIA do not require long-term maintenance therapy. The warm-up and cool-down periods, which are important for any exercise regimen, may help reduce EIA events. A study of military recruits found that exercise-induced asthma attacks did not hinder their ability to perform or train, suggesting that EIA is not a reason to exclude people from physically demanding occupations.

Exercise-induced asthma is distinct from allergic asthma in that it does not produce long-term increase in airway activity. People who only experience asthma when they exercise may be able to control their symptoms with preventive measures such as warm-up and cool-down exercises.

Walking is the best exercise for people with emphysema. Patients should try to walk three to four times daily for 5 - 15 minutes each time. Devices that assist ventilation may reduce breathlessness that occurs during exercise.

Inspiratory muscle training involves exercises and devices that make inhaling (breathing in) more difficult, in order to strengthen breathing muscles. In a 2001 study, patients who took part in an inspiratory muscle training group improved their breathing, walking capacity, and quality of life. Yoga or martial arts exercises, such as tai chi, which emphasize breathing techniques and balanced movements, may be particularly beneficial for patients with emphysema.

Exercise's Effects on Weight

Exercising helps people reduce their weight, maintain weight loss, and fight obesity. Research has shown that women who regularly exercise but do not change their diet can lose significantly more weight than less active women.

Thirty minutes of moderate-intensity exercise may be adequate to maintain cardiovascular health, but it might not prevent weight gain. Recommendations published in 2003 and 2004 suggest that 45 - 60 minutes of exercise per day is necessary to promote weight loss. Children may need more activity.

Losing significant weight requires both exercise and calorie restriction. In addition, if a person exercises without dieting, any actual weight loss may be minimal because dense and heavier muscle mass replaces fat. Nonetheless, regardless of weight loss, a fit body will look more toned and be healthier.

People who exercise are more apt to stay on a diet plan. Exercise improves psychological well-being and replaces sedentary habits that usually lead to snacking. Exercise may even act as a mild appetite suppressant.

Exercising without dieting still adds health benefits. One study found that overweight but fit people have half the death rate of overweight, unfit people. Research suggests that people who have trained for a long time develop more efficient mechanisms for burning fat and are able to stay leaner.

Lifting weights builds muscle, which burns calories more efficiently than other body tissues.

The following are some suggestions and observations on exercise and weight loss:

The treadmill burns the most calories of standard aerobic machines. It may be particularly effective when used in short multiple bouts during the day. Exercise sessions as short as 10 minutes, which are done frequently (about four times a day), may be the most successful program for obese people.
The more strenuous the exercise, the longer the body continues to burn calories before returning to its resting level. This state of fast calorie burning can last for as little as a few minutes after light exercise, to as long as several hours after prolonged or heavy exercise.
Resistance (strength) training is excellent for replacing fat with muscles. It should be performed two or three times a week.
Fidgeting may be very helpful in keeping pounds off. Regular exercise is certainly the best course, but for people who must sit for hours at work, frequently shifting positions while sitting may have some benefit.
It is important to realize that as people slim down, they burn fewer calories per mile of walking or jogging. The rate of weight loss slows down, sometimes discouragingly so, after an initial dramatic head start using diet and exercise combinations. People should be aware of this trend and keep adding to their daily exercise routine.
Changes in fat and muscle distribution may differ between men and women as they exercise. Men tend to lose abdominal fat (which lowers their risk for heart disease faster than reducing general body fat). Exercise, however, does not appear to have the same effect on weight distribution in women. A study of women who practiced aerobic and strength training showed the training resulted in fat loss in the women's arms and trunk. However, they did not gain muscle tissue in those areas.

Because obesity is one of the risk factors for heart disease, anyone who is overweight must discuss their exercise program with a physician before starting.

Exercise's Effects on Other Conditions

Physical activity makes you healthier. It lowers your risk for cardiovascular disease and reduces bone loss. Physical activity also helps the body use calories more efficiently, which helps you eliminate body fat and lose weight. It also helps you maintain weight loss by increasing your metabolism and reducing your appetite.

A number of studies have indicated that regular exercise may reduce the risk of breast, colon, and possibly prostate cancers.

Studies confirm that exercise significantly reduces the risk of both colon cancer (by up to 50%) and breast cancer (by up to 30%).

A 2006 study found that, though protection from breast cancer may vary among the types of tumor, exercise offered the most marked protection from the more aggressive tumors. A second study, also done in 2006, supported this finding. Several studies also suggested that more intense exercise is more protective against breast cancer. Exercising consistently throughout life gives the best protection. Exercise not only lowers a woman's chance of getting breast cancer, it can help those who have received chemotherapy for the disease fight off fatigue.

While endurance athletes may suffer from stomach problems, low intensity exercise has a marked protective effect against colon cancer, according to studies, including the Nurses Health Study and the American Cancer Society's Cancer Prevention Study II. Furthermore, a 2006 study found that people with colon cancer who exercise reduce their risk of a recurrence.

Exercise also has a beneficial effect on people receiving treatment for prostate cancer. A new study found that aerobic and resistance training significantly reduced fatigue in men undergoing radiation treatments for prostate cancer. Fatigue is a common side effect of such treatments. In this study, 122 patients received supervised aerobic training, resistance training, or neither. At the end of 24 weeks, participants in both exercise groups noted significant improvement in their fatigue symptoms, compared to the control group. Participants in the resistance training group also lost a significant percentage of their body fat.

Endurance athletes often report stomach problems, such as bloating, diarrhea, and gas, even at rest. Experts suggest that moderate regular exercise might reduce the risk for some intestinal disorders. These disorders include ulcers, irritable bowel syndrome, indigestion, and diverticulosis. Older people who exercise moderately may have a lower risk for severe gastrointestinal bleeding.

Patients with end-stage kidney disease who exercise four to five times per week have better survival rates than those who are less active, according to researchers involved in the Dialysis Morbidity and Mortality Wave 2 study. However, the majority of study participants said that severe physical limitations prevented them from exercising so often.

Studies have shown that regular exercise, particularly walking, helps reduce one's risk for memory loss. A 2005 study found that older men who walked less than a mile daily had a 71% higher risk of dementia than those who walked more than two miles a day. A 2006 study found that people older than 65 who exercise regularly had lower risk of developing dementia, particularly Alzheimer's disease. An earlier study found that walking regularly protects women from mental decline. To date, there are no clear explanations for this apparent benefit. A preliminary study in mice suggests that physical activity changes the way brain-damaging proteins are processed in the brain, thus slowing the development of Alzheimer's disease. Aerobic exercise has been linked with improved reaction time, perception, and math skills in people of all ages.

Doctors found that exercise improves the physical and emotional well-being of patients who already have Alzheimer's disease. The patients exercised moderately for as little as 60 minutes each week. Doctors noted patients who exercised were less depressed, wandered away less, suffered fewer falls, and were placed in nursing homes later, compared to patients who did not exercise.

People with existing neurological diseases, such as multiple sclerosis, Parkinson's disease, and Alzheimer's disease, should be encouraged to exercise. Specialized exercise programs that improve mobility are particularly valuable for patients with Parkinson's disease. Patients with neurological disorders who exercise experience less stiffness, as well as reduction in, and even reversal of, muscle wasting. In addition, the psychological benefits of exercise are extremely important in managing these disorders. Exercise machines, aquatic exercises, and walking are particularly useful.

Some research has suggested that exercise may have antidepressant effects. Although there is little strong evidence that exercise can help manage depression, a number of studies have suggested benefits. Research findings include:

Just 30 minutes of brisk exercise three times a week was as effective as medication in relieving symptoms, and reducing relapse, in many patients with mild-to-moderate depression.
Over half of older women with depression that did not respond to medication improved with 10 weeks of exercise. (About a third of women who did not exercise also improved during that time.)
Studies on elderly, depressed patients report modest benefits from exercise, even in those who do not response to antidepressants. Simply participating in a group activity may help improve mood.
Teenagers who are active in sports have a greater sense of well-being than their sedentary peers. The more vigorously they exercise, the better their emotional health.
Physical inactivity is strongly linked to depression in children 8 - 12 years of age.

Specific exercises may be particularly beneficial:

Aerobics. Either brief periods of intense training or prolonged aerobic workouts can raise levels of certain chemicals in the brain. These chemicals -- which include endorphins, adrenaline, serotonin, and dopamine -- produce the so-called runner's high. Weight loss and increased muscle tone can boost self-esteem.

Yoga. Yoga practice, which involves rhythmic stretching movements and breathing, has been found to positively affect mood. It may have clinical potential as a technique for improving and stabilizing mood. A study comparing yoga to aerobic exercise found that men have significantly lower levels of tension, fatigue, and anger after yoga, compared with levels after swimming. Yoga and swimming tended to produce equal benefits in women.

Click the icon to see an image of the benefits of yoga.

Moderate exercise in healthy pregnant women does not increase the risk for miscarriage, preterm labor, or rupture of the membrane. Not exercising increases the risk for complications, including low-birth weight babies. Exercising increases the fetal heart rate, which in turn protects the baby.

Healthy women with normal pregnancies should exercise at least three times a week, being careful to warm up, cool down, and drink plenty of liquids. Many prenatal calisthenics programs are available.

The following are specific exercises that may benefit the pregnant woman:

Swimming and water aerobics may be the best option for most pregnant women. Swimming has special benefits for those with fluid buildup. Water exercises involve no impact, overheating is unlikely, and swimming face down promotes optimum blood flow to the uterus.
Performing yoga exercises under the guidance of informed instructors can be very helpful.
Walking is also beneficial.

To strengthen pelvic muscles, women should perform Kegel exercises at least six times a day. This involves contracting the muscles around the vagina and urethra for three seconds 12 - 15 times in a row.

Experts generally recommend the following precautions for pregnant women who exercise:

Fit women who have exercised regularly before pregnancy may work out intensely as long as the doctor approves and no discomfort occurs.
As a rule for previously sedentary, low-risk expectant mothers, the pulse rate should not exceed 70 - 75% of the maximum heart rate, or more than 150 beats per minute. Any sedentary expectant mother should check with her doctor before starting an exercise program.
According to one study, vigorous exercise may improve the chances for a timely delivery. All pregnant women, however, should avoid high-impact, jerky, and jarring exercises, such as aerobic dancing, which can weaken the pelvic floor muscles that support the uterus.
During exercise, women should monitor their temperature to avoid overheating, a side effect that can damage the fetus. (Pregnant women should also not use hot tubs or steam baths, which can cause fetal damage and miscarriage.)

Note: Strenuous exercise may affect the flavor of breast milk for a short time afterward. Nursing mothers who engage in such activity might want to wait about an hour after exercising before they feed their infant.

Complications

Exercise may lead to injury if not done properly. Always exercise with care.

Competitive running or high-impact aerobics pose a high risk of a number of injuries to the bones and muscle. The effect of high-impact exercise on the back is not entirely clear. Some research suggests that over time, high-impact exercise may increase the risk for degenerative disk disease. A survey of people who played tennis, however, found no increased risk for low back pain or sciatica.

High-impact exercise can also cause dizziness, ringing in the ear, motion sickness, or loss of high-frequency hearing.

Some research further suggests that in people unused to exercise, intense activity increases production of harmful particles in the body called free radicals. These unstable oxygen particles injure muscle tissue. Muscle pain in this case does not occur until 24 - 48 hours after exercise.

Some people have a higher than average risk for injury:

About half of people at any age who participate in competitive running or high-impact aerobics experience minor injuries at least once a year. Young, intensely competitive athletes may be at risk for permanent injury. Studies are mixed over whether intensive high-impact sports in younger people cause long-term degenerative joint disease.
As the number of older people who start exercising increases, there has also been an increase in injuries for this age group. Between 1990 and 1996, injuries from active sports increased by 54% in people age 65 and older.
Women are far more likely than men to suffer knee injuries.
Urinary incontinence affects many female athletes who engage in high-impact exercise.
Tennis players are at high risk for injuries from repetitive force on the shoulder joint.

Preventing High-Impact Injuries. The following may be helpful for preventing injury:

Wear shock-absorbing footwear with weight-dampening inserts.
Combine weight lifting with jumping exercises. This may prevent injury by strengthening hamstrings and improving coordination.
Vary training and alternate easy and harder workouts.
Be careful to warm up, cool down, and stretch. Flexibility is the key to preventing many muscle strains.
Take days off now and then. The risk of injury increases when athletes train more than five times a week.

Because of the association between high-impact exercises and oxidation, some experts suggest eating foods rich in antioxidants, such as vitamins A, C, and E. Such foods, which may protect against damage from free radicals, include many fresh fruits and vegetables.

Treating Minor Injuries. Most mild or moderate injuries respond well to a simple, four-step treatment: rest, ice, compression, and elevation (RICE). This combination works well for both spot injuries and chronic problems. Ice packs, which reduce inflammation and pain, can help new injuries, and can be useful for the first few hours after a chronically injured area is exercised. How much or how long to compress the injury is unclear.

Evidence suggests that early movement is helpful, although taping or bracing in people with a recurrent ankle sprain is known to be protective. It may not be helpful in those without a previous ankle injury.

Minor injuries like sprains may be treated at home if broken bones are not suspected. The acronym RICE can help you remember how to treat minor injuries: "R" stands for rest, "I" is for ice, "C" is for compression, and "E" is for elevation. Pain and swelling should decrease within 48 hours. Gentle movement may help, but pressure should not be put on a sprained joint until pain is completely gone. This can take up to a few weeks.

Heat, ultrasound, whirlpool, and massage may speed healing if applied a day or two after the initial injury or for warm-up before another workout session.

Some young female athletes who exercise very intensely, and are subject to intense pressure to remain thin, are at risk for a syndrome known as the female athlete triad. This combination of symptoms includes loss of menstruation, eating disorders, and osteoporosis. Eating disorders among young female athletes are estimated at 15 - 62%. Women at higher risk include ballet dancers, gymnasts, and divers. Continued intense exercise causes a stress response in which estrogen (the primary female hormone) is lost. Estrogen loss can lead to infertility and osteoporosis. Iron loss and anemia may also be a problem in women who exercise frequently, even at moderate intensity. A doctor should be consulted for any of these concerns.

Incorrect movements can literally cause mechanical problems in the muscles. These problems are usually the result of improper exercise instruction, and lack of attention. A single jerky golf swing, or the incorrect use of exercise equipment (especially free weights, nautilus, and rowing machines), can cause serious back injuries.

Between 30 - 70% of cyclists experience low back pain. Pain may be improved by adjusting the angle of the bicycle seat.

Everyone should drink lots of fluid during intense exercise. Thirst is often a poor indicator of dehydration in people who exercise, particularly older people. During a tough workout in a hot environment, the body can lose two liters of fluid per hour through sweat.

Anyone who exercises intensely should take the following precautions:

Drink 6 - 8 ounces of fluid about 15 minutes before a workout, and then pause regularly during exercise to drink more.
Water is the best choice for replenishing body fluids. Glucose-sodium-potassium solutions, the so-called "sports drinks," which promise instant energy, appear to be no better than water at improving endurance during prolonged intense running.
Caffeinated beverages like coffee and soft drinks give short bursts of energy, but can actually cause fluid loss. Caffeine before a workout has been shown to temporarily raise blood pressure, and reduces blood flow to inactive limbs.

Contrary to popular belief, drinking fluids will not cause cramps. Drinking enough, in fact, helps prevent the painful involuntary muscle spasms that sometimes occur during exercise.

Overheating, or hyperthermia, can be a problem with hard exercise, or when working out in hot weather. Overheating can cause mild to life-threatening conditions. Heat exhaustion, a moderate form of hyperthermia, is characterized by the following symptoms:

Lightheadedness, nausea, headache, hyperventilation, fatigue, and loss of concentration
A high temperature (above 103° F), possibly accompanied by complaints of chills and clammy skin

Individuals should rest in a cool, dry place, drink plenty of fluids, and bring down their body temperature with ice packs pressed against the skin.

Heatstroke. Heatstroke is the most dangerous complication of hyperthermia. The victim may suddenly stop sweating, after which symptoms such as altered consciousness, seizures, and even coma may quickly follow. Heat stroke is a medical emergency and requires immediate cooling of the victim in an ice-water bath or with ice packs. One study suggests that risk for serious complications from exercising in high temperatures may persist as late as the following day, even if the weather has cooled down.

Click the icon to see an image of the dangers of heatstroke.

Precautions are also necessary in cold weather. When exercising in winter dress in layers, including gloves and socks, which create insulated air pockets that trap heat. In cold weather, wear shoes with less ventilation than those worn in the summer. Fingers, toes, ears, and nose are most susceptible to frostbite. Frostbite progresses from stinging or aching to numbness. Fingers and toes may become white. Soaking the hands and feet in warm water can help, but only once there is no risk of refreezing, since a second bout of frostbite after thawing can quicken tissue damage.

Hypothermia can be life-threatening and can occur even after long exposure to temperatures that are above freezing. The condition is characterized by extreme fatigue, mental confusion, apathy, and a lack of coordination. The victim should be warmed as soon as possible with blankets, body heat, and warm fluids.

Motivation

Motivation, or a lack thereof, is one reason many people stop exercising. Here are some tips for avoiding burnout:

Think of exercise as a menu rather than a diet. Choose a number of different physical activities that are personally enjoyable such as sports, dancing, or biking. Although experts say you should get 30 minutes of aerobic exercises at least five times a week, those times can be divided into shorter periods -- such as 10 minute sessions. In addition, people can achieve health benefits from other exercise programs, including weight training, yoga, or tai chi.
Stick to a prepared schedule and record progress.
Develop an interest or hobby that requires physical activity.
Adopt simple routines such as climbing the stairs instead of taking the elevator, walking instead of driving to the local newsstand, or canoeing instead of zooming along in a powerboat.
Try cross training (regularly switching from one type of exercise to another). Studies suggest it is more beneficial than focusing only on one form of exercise.
Exercise with friends.
Join a gym or take classes. Many affordable programs are available.
For those who can afford them, personal trainers can be very helpful and are available in many gyms and exercise clubs. Personal trainers without any connection to a well-reputed gym or fitness club should be certified by a major fitness organization, such as the Aerobics and Fitness Association of America (AFAA) or the American Council on Exercise.
Exercise videos may also be helpful, but people should be sure they are suited to their individual age and health needs, and bear the seal of the AFAA.
Consider getting a dog. A study in the February 2006 American Journal of Preventive Medicine found that dog owners in Canada walk almost twice as much as those who don’t own a dog. Regular walking is a good way to improve health.

Differences in Motivation Between Men and Women. Motivation factors may differ by gender, and women appear to have a harder time. In one study, weight loss was the greatest motivator to exercise for women, and muscle tone was the primary motivator for men. Unfortunately, effects on appearances may take a long time to show, discouraging people from continuing an exercise program even though their health is improving.

Overweight among children and adolescents has now become an epidemic in the United States. Experts say that children should be vigorously active for at least 20 - 60 minutes 3 - 5 days a week. Parents and schools must be imaginative and rigorous in encouraging children to exercise.

Role of Parents. Parents must make conscious efforts to limit sedentary activities, and to encourage physical ones for their children. This includes monitoring the time children spend on the computer, in front of the TV, or playing video games. Parents should suggest different forms of entertainment. Even children who aren't interested in joining a Little League team may enjoy a round of catch with their parents, walking in the park, or swimming in a local lake.

Role of Schools. Early school physical education programs can make a significant difference and the earlier these routines are learned, the more likely they will be carried forth into a healthy adulthood. Schools should emphasize team cooperation or individual improvement and self-mastery. Studies have shown that people tend to give up more quickly and feel less competent if their perceptions of success are based only on comparison to their peers.

People mature at different rates, and there seems to be a genetic component to coordination, strength, speed, and one's response to resistance exercise. Nonetheless, everyone should strive to be as fit as they possibly can, given their strengths and limitations.

The decision to adopt a healthier behavior -- whether it's more exercise, weight loss, or quitting smoking -- is not as simple as just deciding to do it. Behavior change expert James Prochaska and his colleagues outlined a theory, which has been supported by numerous studies, showing that people cycle through a variety of stages before a new behavior is successfully adopted over the long term. It may help you to understand how this works. As you read the description of each stage -- specifically as it relates to exercise -- you may find yourself nodding and saying to yourself, "Yes, that's me!"

Stage 1: Pre-Contemplation. People at this stage have no plans or desire to exercise. They aren't even considering exercising. They are generally unaware of the specific benefits that exercise can bring -- exercise may seem more like a hassle than something worth doing. Or, they may simply have "failed" in the past and have given up.

There's no point in talking about how to start an exercise program if you are at this stage. Instead, it is important to think about how exercise might be good for you personally -- by helping you to lose weight, feel better, have more confidence, live longer, sleep better, or reduce your stress levels. The benefits must be identified before a person will consider exercise.

If you are at this stage, a good activity is to ask four friends or family members why they exercise. Their answers may show you some real-life benefits, and inspire enough interest to compel you to take the next step.

Stage 2: Contemplation. A person at this stage is thinking, "I think I should probably exercise, but I need help getting started." People at this stage know that exercise is good for them, but it seems like a daunting task or they don't think they can pull it off. Some may have tried and "failed" in the past, but they are still receptive to another go-round.

It's important for people at this stage to consider some of the truths and falsehoods of exercise. For example, it is helpful to know that there are many forms of physical activity to select from, and that you can do your exercising in small chunks. It is not true that exercise has to be painful, or that you either succeed or fail. There is no such thing as "failure" -- people become more or less active at different stages of their lives, and it is never too late to get moving again. And people at this stage should find assurance that an exercise plan can be very simple.

If you are at this stage, a good activity is to write down all the things that you believe make exercise difficult -- and to learn strategies for overcoming or side-stepping those hurdles. People at this stage might benefit from making a pledge, contract, or other commitment that they are going to get more active in the near future. The goal is to get un-stuck by identifying the roadblocks and the ways to overcome these roadblocks. The final goal at this stage is to make a commitment.

Stage 3: Preparation. These folks are primed and motivated. They are ready to give exercise a try. The goal of this stage is to create a specific action plan that takes all factors into account, so that the "launch" is successful. People at this stage need to know how much they should be exercising, their target heart rate, and the types of exercises. They should explore the different kinds of exercises and decide which ones to try.

At this stage, people will evaluate exercise machines and health plans, if that interests them, pick the proper clothing or accessories, and consult a doctor if necessary. They also need to think about how they are going to fit their exercise plans into their daily and weekly schedule.

If you are at this stage, you should also consider some backup plans -- what to do if it rains, or if you don't feel like exercising. That way you are prepared to overcome that hurdle when you encounter it. You should be aware of what to expect realistically at the beginning -- for example, be aware that weight loss takes time, but health benefits begin immediately.

Stage 4: Action! People at this stage have just started exercising. This stage is where the biggest behavior change occurs -- these people have started to exercise but it is not yet a long-term, ingrained habit. This stage requires significant commitment and energy.

If you are at this stage, keep talking to friends and family for inspiration. Review your backup plans. Reward yourself for small achievements. Give yourself notes and reminders to exercise. Having a friend to exercise with can be very helpful as you get through this stage. You want to build and maintain momentum, because exercising gets easier once it is a habit!

Stage 5: Maintenance. The people at this stage have been exercising for at least 6 months. At this point, exercising has started to become a habit. The goal here is to prevent relapse. If you are at this stage, identify ways that you can fine-tune your program. Continue to identify roadblocks and improve your backup plans. Think about what you have found most enjoyable about exercising.

What benefits have you gained? Keep reminding yourself of these perks. If giving yourself a challenge was part of your initial motivation, set new goals and find new challenges. If you risk getting bored with your routine, find ways to vary it. Or maybe you have found a comfortable routine that you enjoy -- if it's working, great! There is no need to change it. You might want to read or learn more about your method of exercising, and develop a deeper level of understanding about it. Soon you'll be a pro!

One point about this theory is that people do not proceed from one stage to another in a simple, step-by-step fashion. They actually cycle or spiral back and forth, so that they may move from stage 1 to 2 to 3, and then back to 2 again. They may stay in maintenance mode for years and then fall back to stage 2. Remember that this is normal -- if you tried exercising in the past and didn't stick with it, don't consider yourself a failure. Just know that it's time to try again!

Resources

http://fitness.gov -- The President's Council on Physical Fitness and Sports
www.ncppa.org --National Coalition for Promoting Physical Activity
www.acefitness.org --American Council on Exercise
www.arthritis.org --The Arthritis Foundation offers tips on exercising with arthritis
www.justmove.org -- Just Move (American Heart Association)

References

Taylor, A.H., Ussher, M., & Faulkner, G. The acute effects of exercise on cigarette cravings, withdrawal symptoms, affect and smoking behaviour: a systematic review. Addiction. 2007;102:534-543.

Kruk J. Lifetime physical activity and the risk of breast cancer: a case-control study. Cancer Detect Prev. 2007;31(1):18- 28.

Tehard B, Friedenreich CM, Oppert JM, et al. Effect of physical activity on women at increased risk of breast cancer: results from the E3N cohort study. Cancer Epidemiol Biomarkers Prev. 2006 Jan;15(1):57-64.

Adams SA, Matthews CE, Hebert JR, et al. Association of physical activity with hormone receptor status: the Shanghai Breast Cancer Study. Cancer Epidemiol Biomarkers Prev. 2006 Jun;15(6):1170-8.

Larson EB, Wang L, Bowen JD et al. Exercise is associated with reduced risk for incident dementia among persons 65 years of age and older. Ann Intern Med. 2006 Jan 17;144(2):73-81.

Meyerhardt JA, Heseltine D, Niedzwiecki D, et al. Impact of physical activity on cancer recurrence and survival in patients with stage III colon cancer: findings from CALGB 89803. J Clin Oncol. 2006 Aug 1;24(22):3535-41.

Slattery ML. Physical activity and colorectal cancer. Sports Med. 2004;34(4):239-52.

Peters HP, De Vries WR, Vanberge-Henegouwen GP et al. Potential benefits and hazards of physical activity and exercise on the gastrointestinal tract. Gut. 2001 Mar;48(3):435-9.

Abbott, RD, White, LR, G. Ross, W, et al. Walking and Dementia in Physically Capable Elderly Men. JAMA. 2004;292:1447-1453

Calton BA, Lacey JV Jr, Schatzkin A, Schairer C, Colbert LH, Albanes D, Leitzmann MF. Physical activity and the risk of colon cancer among women: A prospective cohort study (United States). Int J Cancer. 2006 Feb 17; [Epub ahead of print]

Di Loreto C, Fanelli C, Lucidi P, et al. Make your diabetic patients walk: long-term impact of different amounts of physical activity on type 2 diabetes. Diabetes Care. 2005 Jun;28(6):1295-302.

Mikkelsson LO, Nupponen H, Kaprio J, Kautiainen H, Mikkelsson M, Kujala UM. Adolescent flexibility, endurance strength, and physical activity as predictors of adult tension neck, low back pain, and knee injury: A 25 year follow up study. Br J Sports Med. 2006 Feb;40(2):107-13.

Brown SG, Rhodes RE. Relationships among dog ownership and leisure-time walking in Western Canadian adults. Am J Prev Med. 2006 Feb;30(2):131-6.

Simons R, Andel R. The effects of resistance training and walking on functional fitness in advanced old age. J Aging Health. 2006 Feb;18(1):91-105.

Review Date:
4/30/2007
Reviewed By:
Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.

A.D.A.M. Copyright

adam.com

Greatest American Dog: How Did Bella Starlet Dog Get Named?

PetSugar — Wed, 27 Aug 2008 12:40:38 -0700

I recapped last Wednesday's episode of Greatest American Dog with some answers from my chat with Beth Joy, but here's the rest of the interview – you don't think I'd get off the phone without asking about her pooch's name, do you? Don't forget to tune in tonight at 8 p.m. to see which duo's going home this week!

PetSugar: How did you decide on her name?
Beth Joy: When I rescued her, her name was Maggie and I was like "eh, you're too beautiful – you're bella" so I named her that. She does movies so she has her middle name Starlet, all my dogs and cats have middle names it's not just Bella. Her nicknames are Cuddle Muffin, Puppy Monkey, Baby Girl, Smoopy, it's a wide range however I'm feeling.

PetSugar: What's it like seeing her on TV?
Beth Joy: She looks gorgeous! It's funny to see her and let all of America and the world see who she is. It's just an honor. I love watching her and every time it's on, she sits in her California bed that we got from the show and watches herself.

PetSugar: Is there anything you wished you'd see more of?
Beth Joy: This show should have been so much more about all the dogs having fun than all the drama. There are some funny things that happened in the pool and wild stuff around the house that they didn't show and it was sad because that was really what we all (as the cast members) thought that they would have shown because it's about dogs.

PetSugar: What was your experience being on the show?
Beth Joy: We learned amazing things on the show, dogs can learn tricks at any age, I want everybody to know that. I'm happy to be the one representing rescue dogs with Bella Starlet on the show, she's a pure mutt and she's quite an amazing dog as you can see on her website – we have fun.

Learn what's up next for Bella Starlet Dog when you read more.

PetSugar: Does she get recognized now in NYC?
Beth Joy: Totally! She got recognized yesterday, this little girl came up and asked if she could pet the dog and she was like "Mommy, it's Bella Starlet!" and her mom and all these other kids come running – it was so cute. Bella just wags her tail and greets them and it's so adorable. She knows who she is, she prances when she walks, she really is Bella Starlet Dog. It's her trademark.

PetSugar: How does Bella get along with your other pets?
Beth Joy: She's the diva, the actress dog of the group, she plays with them once in a while. She doesn't really think she's a dog. She does her own thing, like me, we go to the beat of our own drummer.

PetSugar: What's up next for you both?
Beth Joy: We have some surprises in the works but I don't really want to talk about it because I don't want anyone taking my ideas. Bella's always surprising and doing fun stuff. We have her Halloween float coming up for the Village parade and the theme is "Totally Pawsome '80s" and we're going to dress really funny '80s style and it will be cool.

Source

Asthma in children and adolescents

FitSugar — Wed, 08 Oct 2008 17:35:28 -0700

In This Report

Highlights
Introduction
Causes
Prognosis
Risk Factors
Symptoms
Diagnosis
Treatment
Quick-Relief Medications...
Long-Term Relief Medication...
Other Treatments
Managing Asthma
Resources
References

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

Drug Warning

In 2007, the FDA requested the manufacturers of omalizumab (Xolair) to include a “boxed warning” emphasizing that this drug may cause a severe and life-threatening allergic reaction (anaphylaxis). Health care providers need to carefully observe patients for 2 hours after they receive an omalizumab injection. However, because an allergic reaction can occur up to 24 hours after the injection, patients need to know the signs and symptoms of anaphylaxis and how to self-administer emergency treatment. Omalizumab is approved for patients ages 12 and older who have moderate-to-severe asthma related to allergies.

Drug Approval

In 2006, budesonide/formoterol (Symbicort) was approved for patients age 12 years and older. Symbicort combines a corticosteroid and a long-acting beta2-agonist into a single inhaler.

Inhaled Corticosteroids

Inhaled corticosteroids may help reduce wheezing in young children with breathing problems, but they do not help prevent the development of asthma, according to several 2006 studies in the New England Journal of Medicine.
Inhaled corticosteroids work better than a corticosteroid/long-acting beta2-agonist combination or a leukotrine receptor antagonist drug in treating children with mild-to-moderate asthma, suggests a 2007 study in the Journal of Allergy and Clinical Immunology.

Long-Acting Beta2-Agonists

Long-acting beta2-agonist drugs such as salmeterol (Serevent Diskus) and formoterol (Foradil Aerolizer) may worsen asthma symptom severity and increase the risk for asthma-related death, indicates a 2006 review in the Annals of Internal Medicine.
Products that contain salmeterol and formoterol now have strengthened warning labels detailing these risks.

Childhood Asthma Statistics

Asthma death rates among children have largely declined since 1999 while doctors’ office visits for asthma treatment have more than doubled, indicates a recent report from the U.S. Centers for Disease Control and Prevention.

Introduction

The word asthma originates from an ancient Greek word meaning panting. Essentially, asthma is an inability to breathe properly. When any person inhales, the air travels through the following structures:

Air passes into the lungs and flows through progressively smaller airways called bronchioles. The lungs contain millions of these airways.
All bronchioles lead to alveoli, which are microscopic sacs where oxygen and carbon dioxide are exchanged.

The major features of the lungs include the bronchi, the bronchioles, and the alveoli. The alveoli are the microscopic blood vessel-lined sacks in which oxygen and carbon dioxide gas are exchanged.

Asthma is a chronic condition in which these airways undergo changes when stimulated by allergens or other environmental triggers. Such changes appear to be two specific responses:

The hyperreactive response (also called hyperresponsiveness)
The inflammatory response

These actions in the airway cause patients to cough, wheeze, and experience shortness of breath (dyspnea), the classic symptoms of asthma.

In the hyperreactive response, smooth muscles in the airways constrict and narrow excessively in response to inhaled allergens or other irritants. Airways in everyone's lungs respond by constricting when exposed to allergens or irritants but there are major differences in the hyperreactive response that occurs in people with asthma:

When people without asthma breathe in and out deeply, the airways relax and open in order to rid the lungs of the irritant.
When people with asthma try to take those same deep breaths, their airways do not relax but instead narrow, causing the patients to pant for breath. Smooth muscles in the airways of people with asthma may have a defect, perhaps a deficiency in a critical chemical that prevents the muscles from relaxing.

The hyperreactive stage is followed by the inflammatory response, which generally contributes to asthma in the following way:

The immune system responds to allergens or other environmental triggers by delivering white blood cells and other immune factors to the airways.
These so-called inflammatory factors cause the airways to swell, fill with fluid, and produce a thick sticky mucus.

Click the icon to see an image of a normal versus asthmatic bronchiole.

This combination of events results in wheezing, breathlessness, inability to exhale properly, and a phlegm-producing cough.

Inflammation appears to be present in the lungs of all patients with asthma, even those with mild cases, and plays a key role in all forms of the disease.

Causes

Asthma occurs in about 5 million American children. Each year about 200,000 of them are hospitalized. It is the most common chronic childhood illness. About half of all cases of asthma develop before the age of 10, and about 80% of patients develop symptoms before they are 5 years old.

The mechanisms that cause asthma are complex and vary among population groups and even individuals. For example, asthma in children is highly associated with allergies. However, only a minority of children with allergies have asthma, and allergic response cannot explain all cases of asthma. Other factors, such as genetics or environmental conditions are probably involved in the development of asthma. Most likely, several genes combine to make a child susceptible to environmental triggers, not only allergens but also possibly infections, dietary patterns, or air pollution. Physical factors, particularly having smaller lungs, affect the chances for later asthma.

Asthma and allergies often coexist, and the allergic response plays a strong role in childhood asthma. About 70 - 85% of children with asthma also have allergies. Some studies suggest that children who have allergies are also at greater risk for developing asthma as adults. A 2006 study found that children who are allergic to dust mites are three times more likely to later develop asthma than children who were not allergic.

However, the evidence is clearly mixed. Several other 2006 studies suggested that avoiding dust mites does not help prevent asthma and, in fact, early exposure to dust mites may even protect children from developing asthma and allergic responses. Some experts think that giving immunotherapy (“allergy shots”) to children with allergies may help prevent asthma development.

An asthma attack can be induced or aggravated by direct irritants to the lungs. Studies indicate that the more indoor allergens a child is allergic to, the higher the risk for severe asthma. Important irritants or allergens include the following:

Dust mites, specifically mite feces, which are coated with enzymes that contain a powerful allergen. These are the primary allergens in the home.
Animal dander. Cats harbor significant allergens, which can even be carried on clothing; dogs usually present fewer problems.
Molds.
Cockroaches. Cockroaches are major asthma triggers and may reduce lung function even in people without a history of asthma.
Pollen. An asthma attack from an allergic response to pollen is more likely to occur during extreme air changes, such as thunderstorms. Major weather changes, such as El Nino, can affect the timing of allergy seasons because they cause seasonal changes (and pollen) to start earlier.
Food allergies. About 8 - 10% of children with asthma also have food allergies. These children also appear to have a high risk for very serious reactions to such foods. In infants and toddlers, allergy to eggs appears to be a predictor of asthma.
Fossil Fuels. Certain chemicals may trigger allergic rhinitis. Some experts believe that refined fossil fuels, such as diesel fuel and particularly kerosene, may be important triggers for allergic rhinitis. In people who already have allergies or asthma, exposure to such fossil fuels may worsen symptoms.

The Allergic Response. The allergic process, called atopy, and its connection to asthma are not completely understood. It involves various airborne allergens or other triggers that set off a cascade of events in the immune system leading to inflammation and hyperreactivity in the airways. One description is as follows:

The conductor in an orchestra of immune factors that contribute to allergies and asthma appears to be a category of white blood cells known as helper T cells, in particular a subgroup called Th2 cells.
Th2 cells overproduce interleukins (ILs), immune factors that are molecular members of a family called cytokines, which are involved in the inflammatory process.
Interleukins 4, 9, and 13, for example, may be responsible for a first-phase asthma attack. These interleukins stimulate the production and release of antibody groups known as immunoglobulin E (IgE). (People with both asthma and allergies appear to have a genetic predisposition for overproducing IgE.)
During an allergic attack, these IgE antibodies can bind to special cells in the immune system called mast cells, which are generally concentrated in the lungs, skin, and mucous membranes. This bond triggers the release of a number of active chemicals, importantly potent molecules known as leukotrienes. These chemicals cause airway spasms, overproduce mucus, and activate nerve endings in the airway lining.
Another cytokine, interleukin 5, appears to contribute to a late-phase inflammatory response. This interleukin attracts white blood cells known as eosinophils. These cells accumulate and remain in the airways after the first attack. They persist for weeks and mediate the release of other damaging particles that remain in the airways.

Researchers are investigating the role that T cells play in asthma. T cells are white blood cells that are involved in the immune response. Researchers had focused on the T cell called type 2 helper (ThH2) cells. However, a 2006 breakthrough study in the New England Journal of Medicine suggested that a different type of T cell may play a stronger role in asthma than previously thought.

Researchers discovered that these cells, called natural killer T cells, are far more common in the lungs of people with asthma than in the lungs of healthy people. Natural killer T cells are very rare, but researchers found them in 60% of people with moderate-to-severe persistent asthma. While this research is preliminary, it may explain why corticosteroid drugs do not work well for some patients with asthma: Steroid drugs target Th2 and other inflammatory cells, not natural killer T cells. Researchers think that further investigation of natural killer T cells may lead the way to new types of asthma drugs. If these cells prove to be involved in asthma, then drugs that eliminate them might become an important new treatment.

Over the course of years the repetition of the inflammatory events involved in asthma can cause irreversible structural and functional changes in the airways, a process called remodeling. The remodeled airways are persistently narrow and can cause chronic asthma. Researchers are trying to determine how this process occurs:

Interleukins. Some researchers are looking at potent immune factors, including interleukins 11 and 13. They have been linked to a number of processes possibly involved in remodeling, including scarring in the airways and overgrowth of cells in the smooth muscles that line the airways.

Growth Factors. Compounds known as vascular endothelial growth factor (VEGF) have been observed in the airways of patients with asthma. VEGF is a powerful promoter of cell growth in blood vessel linings and some researchers believe it may be major factor in remodeling.

About one-third of all persons with asthma share this condition with another member of their immediate family. Asthma may be more likely to be passed to children from the mother than from the father. Both allergies and asthma are strongly associated with hereditary factors, sharing certain genetic markers, but they are not always inherited together.

Research on the genetics of these conditions is confusing. Of some significant promise, researchers have identified a gene (ADAM33), which has been linked to asthma. The gene regulates one of the enzymes called metalloproteases, which are involved with the smooth muscle in the airway. A mutation of this gene could play a role in airway changes that occur after inflammation.

The role of early childhood respiratory and intestinal infections is very complex. Viral respiratory infections certainly worsen existing asthma, but the most common ones are unlikely to be causes of childhood asthma. In fact, early respiratory and intestinal infections may offer some protection against asthma.

Early Respiratory Infections as Causes of Asthma. Studies suggest that most respiratory infections are not important causes of asthma in children, except in certain cases. An important exception is the respiratory syncytial virus (RSV), which has been implicated in the development of asthma. RSV is the major viral cause of infant pneumonia. Studies also indicate that infants who have reduced lung function within a few days after birth are at increased risk of developing asthma by the time they are 10 years old.

Common Respiratory Infections Worsen Asthma. Common respiratory infections viruses that cause colds (such as the rhinovirus) may in some cases be associated with the development of asthma. A 2007 study suggested that children who have a wheezing rhinovirus during infancy are at increased risk for developing asthma by age 6. Even if these viruses do not directly cause asthma, they can worsen asthma in children who already have it. Rhinovirus has been reported to be the most common infection associated with asthma attacks. In one study, it was associated with 61% of asthma worsening in children. Some research suggests that colds promote inflammation in patients with existing asthma and increase the intensity of airway responsiveness for weeks.

The Hygiene Theory: Early Infections as Protection Against Asthma. Another blames the dramatic increase in asthma on the reductions in childhood infections that have occurred with modern hygiene and antibiotic use. The basic theory rests on the idea that infections stimulate production of specific immune factors called Th1 cells. As these cells build up, they replace other immune factors called Th2 cells, which react to allergens -- a less serious threat to the body. Without infections to stimulate the production of the Th1 infection fighters, the Th2 allergen fighters are not replaced, and they persist at high levels, making the growing child more susceptible to allergies and asthma.

A number of different studies support this theory:

Some studies suggest that being part of a large family or attending day care increases the risk for early respiratory infections but reduces the risk of childhood asthma. The occasional cold, then, may be protective.
In one study, researchers measured levels of bacterial byproducts called endotoxins in the mattress dust of 812 children. Those with the highest levels had 80% lower rates in allergies and asthma.
Another study further found a strong association between allergy development and the absence of certain beneficial bacteria (called probiotics) carried in the infant's intestines. Infants who were born in more hygienic environments tended to lack these bacteria. Antibiotic overuse and modern hygiene may be reducing these helpful organisms. (Probiotics can be obtained in active yogurt cultures and in supplements, which are being studied for protection.)

The standard vaccinations against serious childhood infections, according to several important studies, pose no risk for asthma. One of the studies even reported some lower risk for asthma and allergies in the second and third years after vaccinations. Infections killed thousands of children every year before immunization became widespread. Asthma, although serious, is rarely fatal in children. No one should stop giving their children vaccinations against childhood killers.

GERD. At least half of patients with asthma also have gastroesophageal reflux disease (GERD), the cause of heartburn. It is not entirely clear which condition causes the other or whether they are both due to common factors.

Heartburn is a condition where the acidic stomach contents back up into the esophagus causing pain in the chest area. This reflux usually occurs because the sphincter muscle between the esophagus and stomach is weakened. Standing or sitting after a meal can help reduce the reflux which causes heartburn. Continuous irritation of the esophagus lining as in gastroesophageal reflux disease is a risk factor for the development of adenocarcinoma.

Some theories for the causal connection between GERD and asthma are:

Acid leaking from the lower esophagus in GERD stimulates the vagus nerve, which runs through the gastrointestinal tract. This stimulated nerve, in turn, triggers the nearby airways in the lung to constrict, causing asthma symptoms.
Acid back-up that reaches the mouth may be inhaled into the airways (aspirated). Here, the acid triggers a reaction in the airways that cause asthma symptoms.

GERD is sometimes hard to detect and might be suspected as a contributor in the following patients:

Those who do not respond to asthma treatments.
Those whose asthma attacks follow episodes of heartburn.
Those whose attacks are worse after eating or exercise.
Those whose coughs follow episodes of acid reflux. (One study found that GERD was associated with about half of the episodes of coughs and wheezes in patients with asthma.)

Treating GERD symptoms with anti-acid drugs may resolve asthma in some (but not all) patients who share both conditions. A small 2005 observational study found that while GERD was common in patients with asthma, treatment of GERD had no effect on asthma symptoms. [See In-Depth Report #85: Heartburn and gastroesophageal reflux disease.]

Sinusitis. Almost half of children and adults with allergic asthma have sinus abnormalities, and in various studies, between 17 - 30% of patients with asthma develop true sinusitis. The presence of sinusitis, however, does not appear to increase the severity of asthma.

Click the icon to see an image of sinusitis.

Parental Migraines and Childhood Asthma. Some studies have reported a link between childhood asthma and parental migraines, with one small study suggesting that children are about five times more likely to develop asthma if their parents have a history of migraines.

Exercise-induced asthma (EIA) is a limited form of asthma in which exercise triggers coughing, wheezing, or shortness of breath.

About 10% of adults and some fewer children have aspirin-induced asthma (AIA). With this condition, asthma gets worse when patients take aspirin. Aspirin is one of the drugs known as nonsteroidal anti-inflammatory drugs (NSAIDs). Although aspirin is used to reduce inflammation in other disorders, it appears to have the opposite effect in many asthma cases. It is not wholly known why this occurs. AIA often develops after a viral infection. It is a particularly severe asthmatic condition and is associated with up to 25% of asthma-related hospitalizations. In about 5% of cases, aspirin is responsible for a syndrome that involves multiple attacks of asthma, sinusitis, and nasal congestion. Such patients also often have polyps (small benign growths) in the nasal passages.

Patients with aspirin-induced asthma (AIA) should avoid aspirin and most likely NSAIDs, including ibuprofen (Advil) and naproxen (Aleve).

Acetaminophen (Tylenol) has been the traditional alternative for relief of minor pain for patients who are aspirin-sensitive. Unfortunately, recent evidence has muddied these recommendations. Moreover, some asthmatic episodes have been linked to high consumption of acetaminophen among adults. And a study of children with asthma reported that those who took ibuprofen were less likely to be hospitalized for asthma than those taking acetaminophen. This is of particular concern, since acetaminophen is the pain reliever of choice in small children.

Asthma occurs primarily at night (nocturnal asthma) in as many as 75% of patients with the condition. Attacks often occur between 2 - 4 a.m. Factors that might play role in nocturnal asthma may include one or more of the following:

Chemical and temperature changes in the body during the night that increase inflammation and narrowing of the airways
Delayed allergic responses from exposure to allergens during the day
The wearing off of inhaled medications toward the early morning
An increase in acid reflux (back up of stomach acid) that causes airways to narrow
Postnasal drip that occurs during sleep
Conditions relating to sleep, such as sleep apnea or sleeping on one's back, which may worsen any asthma attack that occurs at night

Some experts believe that nocturnal asthma may actually be a unique form of asthma with its own specific biologic mechanisms that occur only at night and which reduce natural steroid hormones (which block inflammation).

Exercise-induced asthma (EIA) is a limited form of asthma in which exercise triggers coughing, wheezing, or shortness of breath. This condition generally occurs in children and young adults, most often during intense exercise in cold dry air. Symptoms are generally most intense about 10 minutes after exercising and then gradually resolve.

EIA is triggered only by exercise and is distinct from ordinary allergic asthma in that it does not produce a long duration of airway activity, as allergic asthma does. (However, some people have both forms of asthma.) People who have only EIA do not appear to require long-term maintenance therapy. A study of military recruits with EIA also reported that the condition does not hinder a person's overall physical performance.

Medications. Cromolyn, a mild anti-inflammatory drug, or short-acting beta2-agonists have been the treatments of choice for preventing EIA. Newer approaches for people who work out regularly include pretreatment with long-acting beta2-agonists, such as salmeterol (Serevent) or the regular use of inhaled corticosteroids.

Hints for Reducing EIA. EIA occurs only after exercise and is more likely to occur with regular paced activities in cold, dry air. The following are some suggestions for reducing its impact:

Warm-up and cool-down periods are important.
Patients with EIA might do better with activities that involve short bursts of exercise (tennis, football) than with exercises involving long-duration regular pacing (cycling, soccer, and distance running).
Breathing through a scarf or through the nose helps warm up the airways.
Restricting dietary salt might help reduce EIA.

Click the icon to see an image of exercise-induced asthma.

Prognosis

Asthma is the third major cause of hospitalization in children under age 15. The condition can be very serious in children, particularly those younger than age 5, because their airways are very narrow.

The severity of asthma is graded as mild intermittent and mild, moderate, and severe persistent. A patient in any of these categories, even mild intermittent, can still experience a severe and even life-threatening attack. According to one report, 30% of asthma deaths occur in patients with mild asthma.

Asthma is rarely fatal in children, with only 187 asthma deaths reported in 2002 in children under age 18. In fact, a 2006 study from the U.S. Centers for Disease Control and Prevention reported that asthma death rates for children have steadily declined since 1999. (During the same time, the number of doctor visits for asthma treatment more than doubled.) Even low mortality numbers are unacceptable, however, since asthma deaths are largely preventable.

Factors associated with an increased risk of death from asthma in children include:

Previous life-threatening episodes of asthma
Lack of adequate and ongoing health care. (Most likely the reason for the higher fatalities rates in minority children.)
Significant behavioral problems
Underestimating the severity of an acute attack poses the greatest threat. Unfortunately, one study of children found that nearly 40% of them were unaware of asthmatic symptoms when they occurred.

African American children have more than six times the death rate of Caucasians in the age groups of 4 years and younger and 15 - 24 years. Hispanic children also have a higher risk.

The following signs and symptoms may indicate a life-threatening situation:

As the chest labors to bring enough air into the lungs, breathing often becomes shallow.
Lacking sufficient oxygen, the skin becomes bluish.
The flesh around the ribs of the chest appears to be sucked in.
The patient may begin to lose consciousness.

Asthma often progresses very slowly to a serious condition or may develop to a fatal or near-fatal attack within a few minutes. It is very difficult to predict when an attack will become very serious. Early symptoms or lack thereof do not always reflect the ultimate severity of an attack. Some studies even suggest that people at high risk for fatal or near-fatal asthma attacks are those with poor awareness of their own reduced ability to breathe and who are slow in seeking help. Monitoring peak flow rates is, therefore, an important management component, since it provides a more accurate assessment of lung function than symptoms alone.

In a 2003 study, researchers followed people with asthma for longer than 30 years. About a third of children had outgrown their asthma in adulthood. In general, the more severe the childhood asthma, the greater the likelihood that it will persist. For example, only 23% of children who experienced wheezy bronchitis (wheezing during respiratory infections) suffered from frequent or persistent asthma in adulthood.

There is evidence that severe asthma can cause long-lasting damage and possibly permanent scarring in some patients. The risk for such injury is highest, however, when asthma strikes children in the first 3 - 5 years. There does not appear to be any significant risk for long-term lung damage for children who develop mild-to-moderate persistent asthma between ages 5 - 12. Children adapt well to living with asthma, and even with severe asthma they can function as well as healthy children in virtually all areas of life.

Studies are mixed over the effects of emotional disorders on the severity of asthma. One study indicated that parents of children with asthma may suffer greater psychological stress than their children. A 2000 study reported that mild-to-moderate asthma does not significantly affect the psychological well-being of most children ages 5 - 12. Teenagers and preteens may have particular difficulty coping with what they perceive as the social stigma of asthma. Parents and older children should not hesitate to seek help from support groups, doctors, friends, or family members. Support programs may help children to better manage their asthma and even reduce hospitalization.

Although there have been few studies on the effects of asthma on schooling, a 2000 study reported that nocturnal (nighttime) asthma affected school attendance and performance in children and work attendance in their parents.

Risk Factors

Asthma affects about 5 million American children between the ages of 5 - 14. Asthma has dramatically increased worldwide over the last few decades, in both developed and developing countries. From 1980 - 1994, asthma increased 160% in American children younger than 4 years and has also dramatically risen worldwide. Experts are puzzling over the cause of this phenomenon. Possible causes and risk factors that are suspects in the dramatic rise in asthma in children include:

Survival rates are now higher in low-birth-weight babies, who may be more susceptible to asthma.
Declining rates in nursing may be a contributor. Breast milk contains important anti-inflammatory substances, such as omega-3 fatty acids, which might protect against asthma.
Western dietary habits (which commonly include more fast foods and less fruits, vegetables, fiber, minerals, and other nutrients) may contribute to the development of childhood asthma.
Children are spending more time indoors watching television, playing video games, or using the computer and are, therefore, overexposed to indoor allergens.
The trend of making homes more energy-efficient may result in dust mites being trapped inside them.

Among younger children, asthma develops twice as frequently in boys as in girls, but after puberty it may be more common in girls.

Urban Life. Urban life is strongly associated with a higher risk. Although poverty plays a significant role, urban life has been associated with a higher risk for asthma in any income group and among both children and adults. In some urban areas, as many as 25% of children have asthma or show signs of wheezing. In fact, it may be greatly underdiagnosed in city children. A 1999 study reported that almost a third of children in inner-city kindergartens had asthma symptoms without a diagnosis of the disorder; 10% had actually been diagnosed with asthma, mainly because their symptoms were severe.

Ethnicity. Since 1980, asthma rates have risen the most dramatically among African American children, and they have significantly higher rates of asthma than Caucasian children. Hispanic children are also at higher risk. Both groups of minority children are more likely to have fatal asthma than Caucasian children.

Some studies indicate that the difference in risk exists simply because African Americans and other minority groups are more likely to live in urban areas. Poverty and lack of access to health care also play a role. However, Caucasian children who live in cities also face a high risk for asthma, and rural African American children do not.

Urban life and socioeconomic factors, however, may not fully explain the ethnic disparity.

Low Birth Weight. Infants of low birth weight are at higher risk for lung problems and asthma.

Winter Birth. Children born in the winter may have a greater risk for asthmatic allergies to cockroaches than children born at other times of the year.

Vitamin D. A 2006 study suggested a link between vitamin D intake during pregnancy and development of early childhood asthma. Pregnant women who had a higher intake of vitamin D were less likely to give birth to children who developed asthma.

Breast Feeding. Most studies on breastfeeding report some protection against wheezing and asthma in the first year of life. Breastfeeding has many other benefits for the child as well. The American Academy of Pediatrics recommends exclusively breastfeeding for the child's first 6 months of life.

Complications of Pregnancy. According to a 2000 study, complications of pregnancy, specifically those involving the mother's uterus (such as post-birth hemorrhage, pre-term contractions, insufficient placenta, and restricted growth of the uterus), are associated with an increased risk of childhood asthma. Another study reported that delivery procedures such as Cesarean section, the use of vacuum extraction or forceps also raised the risk of childhood asthma.

In both adults and children, the incidence of obesity and asthma has been increasing over recent years. Studies report a strong association between the two conditions. Some experts suggest that excess weight pressing on the lungs may trigger the hyperreactive response in the airways typical of asthma. Others believe that asthma leads to obesity by inhibiting physical activity, although several studies have found no difference in activity levels between people with or without asthma. Some studies suggest that many obese people may be misdiagnosed as having asthma when they are simply short of breath, possibly because of the increased effort required for breathing.

In any case, there is evidence that losing weight can relieve asthma symptoms. Some evidence also suggests that people who are overweight (body mass index greater than 25) have more difficulty getting their asthma under control. Weight loss in anyone who is obese and has asthma or shortness of breath reduces airway obstruction and improves lung function. [See In-Depth Report #53: Weight control and diet.].

Damp Homes. Studies suggest that children who live in damp homes have a much higher risk for asthma.

Mental Health. Research indicates that poor mental health of parents and children are significant predictors of more severe symptoms in childhood asthma. A 2000 study suggested that high stress levels can predict the onset and severity of asthma in children genetically at risk for the condition.

Symptoms

In children with asthmatic symptoms, it is important to first consider as a possible cause inhaled foreign objects such as peanuts; viral infections such as croup; and bacterial infections, which may be accompanied by high fever and progress rapidly. Any child who has frequent coughing or respiratory infections should be checked for asthma.

The classic symptoms of an asthma attack include:

Wheezing when breathing out is nearly always present during an attack. Usually the attack begins with wheezing and rapid breathing, and, as it becomes more severe, all breathing muscles become visibly active.
Shortness of breath (dyspnea). Shortness of breath is a major source of distress in patients with asthma, although severe dyspnea does not always reflect a serious attack or reduced lung function.
Coughing. In some people, the first symptom of asthma is a nonproductive cough.
Chest tightness or pain. Initial chest tightness without any other symptoms may be an early indicator of a serious attack.
Neck muscles may tighten, and talking may become difficult or impossible.
Rapid heart rate
Sweating
Chest pain occurs in about 75% of patients. It can be very severe, although its intensity is not necessarily related to the severity of the asthma attack itself.

The end of an attack is often marked by a cough that produces thick, stringy mucus. After an initial acute attack, inflammation persists for days to weeks, often without symptoms. (The inflammation itself must still be treated, however, because it usually causes relapse.)

Diagnosis

The doctor will consider a diagnosis of asthma if a child has a history of periodic attacks of shortness of breath, coughing, and wheezing, perhaps accompanied by tightness in the chest. The parent should describe the pattern of symptoms and possible precipitating factors, including:

Whether symptoms are more frequent during the spring or fall (allergy seasons)
Whether exercise, a respiratory infection, or exposure to cold air has ever triggered an attack
Any family history of asthma or allergic disorders such as eczema, hives, or hay fever

A number of disorders may cause some or all of the symptoms of asthma. Panic disorder can coincide with asthma or be confused with it. Other diseases that must be considered during diagnosis are pneumonia, bronchitis, severe allergic reactions, psychosomatic illnesses, and certain rare disorders (such as tapeworm and trichomoniasis).

If symptoms and a patient's history are indicative of asthma, the doctor will usually perform tests known as pulmonary function tests to confirm the diagnosis and determine the severity of the disease.

Using a spirometer, an instrument that measures the air taken into and exhaled from the lungs, the doctor will determine several values:

Vital capacity (VC), which is the maximum volume of air that can be inhaled or exhaled.
Peak expiratory flow rate (PEFR), commonly called the peak flow rate, which is the maximum flow rate that can be generated during a forced exhalation.
Forced expiratory volume (FEV1), the maximum volume of air expired in 1 second.

If the airways are obstructed, these measurements will fall. Depending on the results, the doctor will take the following steps:

If measurements fall, the doctor typically asks the patient to inhale a bronchodilator. This drug is used in asthma to open the air passages. The measurements are taken again. If the measurements are more normal, the drug has most likely cleared the airways, and a diagnosis of asthma is strongly suspected.
If measurement results fail to show airway obstruction, but asthma is still suspected, the doctor may perform a challenge test. It involves administering a specific drug (histamine or methacholine) that usually increases airway resistance only when asthma is present.

The patient may be given skin or blood allergy tests, particularly if a specific allergen is suspected and available for testing. Allergy skin tests may be the best predictive test for allergic asthma, although they are not recommended for people with year-round asthma.

One of the most common methods of allergy testing is the scratch test or skin prick test. The test involves placing a small amount of the suspected allergy-causing substance (allergen) on the skin (usually the forearm, upper arm, or the back), and then scratching or pricking the skin so that the allergen is introduced under the skin surface. The skin is observed closely for signs of a reaction, which usually includes swelling and redness of the site. With this test, several suspected allergens can be tested at the same time, and results are usually available within about 20 minutes.

Tests that either rule out other diseases or obtain more information about the causes of asthma include the following:

A complete blood count
Chest and sinus x-rays
Computed tomography (CT) scans. CT scans may be helpful in certain cases, such as for determining wall thickness in airways in patients who are difficult to treat, which could signify a higher risk for lung damage.
Examination of the patient's sputum for eosinophils (white blood cells that in high levels are associated with severe allergic asthma).
Researchers are investigating measurements of certain chemicals in sputum or exhaled air that indicate airway inflammation. Such chemical markers include nitric oxide and hydrogen peroxide. For example, high levels of nitric oxide may prove to be a simple and noninvasive way of diagnosing asthma.

Treatment

Treating an Acute Attack in the Hospital. An acute attack may require hospitalization. Laboratory tests, an electrocardiogram (ECG), and a chest x-ray are performed to determine lung function, oxygen levels, and other indications of severity or rule out other causes. Depending on the results, the following treatments may be given:

Beta2-agonists are the standard therapy. They are typically administered with a nebulizer (a device that administers the drug in a fine spray). Studies suggest, however, that even very small children may be able to use metered-dose inhalers (MDIs), which are just as effective and more convenient than nebulizers. (Intravenous delivery is not recommended in most cases.)
An anticholinergic drug (ipratropium) is sometimes added to improve symptoms.
A corticosteroid (commonly called a steroid) given within the first hour helps reduce the need for hospitalization. Steroids may be administered intravenously, as a shot, or orally. Children may respond well to oral steroids.
Oxygen is usually administered, and can be life saving in severe cases.
Infusions of magnesium sulfate open airways and are an important emergency treatment for adults. Its benefits for children need to be further demonstrated.
In life-threatening situations, the patient may require mechanical ventilation.

Antibiotics are not useful for asthma attacks if there is no strong evidence of the presence of a bacterial infection. Viral infections, most often colds and the flu, are more likely to trigger an asthma attack. In such cases, antibiotics are not helpful and may have adverse effects.

Discharge and Relapse After Hospitalization. It typically takes about 3 - 4 hours to determine if a patient can be safely sent home or if they need to stay. Patients are generally discharged when:

Symptoms are gone or minimal, and
The peak expiratory flow rate is 70% or more of the predicted rate

Despite reasonable precautions, between 12 - 16% of patients relapse within 2 weeks of leaving the hospital. Receiving a steroid shot at discharge or taking an oral corticosteroid for a few days can reduce this risk.

Avoiding allergens, following appropriate drug treatments, and home monitoring are key elements in preventing dangerous asthma attacks and hospitalization. In addition, good communication between the doctor and patient is a key factor in a successful management program.

Medications for asthma fall into two categories:

Rescue Medications. Medications that open the airways (bronchodilators, or inhalers) are used to quickly relieve any moderate or severe asthma attack. These drugs are usually short-acting beta-adrenergic agonists (beta2-agonists). Other drugs used in special cases include corticosteroids taken by mouth and anticholinergic drugs. None of these drugs have any effect on the disease process itself. They are only useful for treating symptoms.
Maintenance Medications. Simply coping with asthma symptoms without also controlling the damaging inflammatory response is a common and serious error. For adults and children over age 5 with moderate-to-severe persistent asthma, experts now recommend inhaled corticosteroids and long-acting beta2-agonists.

Parents can greatly reduce the frequency and severity of their children’s asthma attacks by understanding the difference between coping with asthma attacks and controlling the disease over time. Unfortunately, many patients do not understand the difference between medications that provide rapid, short-term relief and those that are used for long-term symptom control. Many patients with moderate or severe asthma overuse their short-term medications and underuse their corticosteroid medications. The overuse of bronchodilators can have serious consequences; not using steroids can lead to permanent lung damage.

Patients need to understand that asthma symptoms can change quickly over time and that treatment strategies may need to change in response. In 2005, the two leading U.S. allergy associations published joint guidelines on controlling asthma. The guidelines emphasize that asthma treatment decisions need to be made on an individual basis. It is important that patients have a close relationship with their doctor. The doctor needs to evaluate a patient’s asthma symptoms at each visit to determine any need for changes in medication. According to the guidelines, asthma management is classified as either “well-controlled” or “not well-controlled.” The doctor may need to change some medications, or increase or decrease the dosage, depending on whether a child’s asthma is well-controlled or not well-controlled.

These are the signs of well-controlled asthma:

Asthma symptoms occur twice a week or less
Rescue bronchodilator medication is used twice a week or less
Symptoms do not cause nighttime or early morning awakening
Symptoms do not limit work, school, or exercise activities
Peak flow meter readings are normal or the patient’s personal best
Both the doctor and the patient consider the asthma to be well controlled


Classification	Symptom Frequency	Children Age 5 Years and Younger: Recommended Treatment	Children Older Than 5 Years: Recommended Treatment
Mild intermittent	At least 2 days per week. At least 2 nights per month.	No daily medication.	No daily medication. If severe attacks occur, systemic corticosteroids recommended.
Mild Persistent	More than 2 days per week, but less than once per day. More than 2 nights per month.	Preferred treatment: Low-dose inhaled corticosteroids with nebulizer, or MDI with holding chamber with or without face mask. Alternative treatment: Cromolyn or leukotriene-antagonist.	Preferred treatment: Low-dose corticosteroids. Alternative treatment: Cromolyn, leukotriene modifier, nedocromil, OR sustained release theophylline.
Moderate Persistent	Daily daytime symptoms. More than 1 night per week.	Preferred treatment: Low-dose inhaled corticosteroids and long-acting beta2-agonists OR medium-dose inhaled corticosteroids. Alternative treatment: Low-dose inhaled corticosteroids and either leukotriene receptor antagonist or theophylline. If needed (especially if severe attacks occur): Medium-dose inhaled corticosteroids and long-acting beta2-agonists; medium-dose inhaled corticosteroids and either leukotriene receptor antagonist or theophylline.	Preferred treatment: Low-to-medium dose inhaled corticosteroids and long-acting beta2-agonists. Alternative treatment: Low-to-medium dose inhaled corticosteroids and either leukotriene receptor antagonist or theophylline, or increased medium dose inhaled corticosteroids. If needed (especially if severe attacks occur): Increase dosage of medium-dose inhaled corticosteroids with add-on long-acting beta2-agonists. Alternatively, increase dosage of medium-dose inhaled corticosteroids plus either leukotriene receptor antagonist or theophylline.
Severe Persistent	Continual daytime symptoms. Frequent nighttime symptoms.	Preferred treatment: High-dose inhaled corticosteroids and long-acting beta2-agonists plus (if needed) oral corticosteroids.	Preferred treatment: High-dose inhaled corticosteroids combined with long-acting inhaled beta2-agonists. Add, if needed: Oral corticosteroids. Repeat attempts should be made to reduce use of systemic corticosteroid and maintain control with inhaled corticosteroid.
Adapted from National Asthma Education and Prevention Program (NAEPP) Expert Panel Report: Guidelines for the Diagnosis and Management of Asthma – Update on Selected Topics 2002 (EPR-2 Update).

Most asthma drugs are inhaled using various forms of inhalers or nebulizers. Inhaled drugs must be used regularly as prescribed and the patient carefully trained in their use in order for them to be effective and safe. Studies suggest that many children fail to use the devices properly, although newer devices are easier to use than others. The basic devices are the metered-dose inhaler (MDI), breath-actuated inhalers, dry powder inhalers, and nebulizers.

MDIs have used chlorofluorocarbons (CFCs) as their propellants. CFCs are damaging to the environment and are now being replaced with other propellants (hydrofluoroalkane) that are more environmentally safe, and do not chill the device as CFCs do. Devices that don't use any propellants are also now available.

Metered-Dose Inhaler. The standard device for administering any asthma medication is the metered-dose inhaler (MDI). This device, particularly when used with a spacer, allows precise doses to be delivered directly to the lungs. (The spacer is a tube that is attached to the inhaler. It serves as a holding chamber for the medication that is sprayed by the inhaler.) MDI-delivered drugs must be used regularly as prescribed and the patient carefully trained in their use in order for them to be effective and safe. Some patients hold the MDI too close to their mouths, or even inside them. Others may exhale too forcefully before inhalation.

The spacer helps improve medication delivery by allowing the patient additional time to inhale. They vary, however, in their effectiveness. It should be noted that MDIs can continue to deliver propellant even after the drug has been used up. Patients should track their medicine and throw the device away when the last dose has been administered.

Nebulizers (not MDIs) are typically used in very small children, both at home and in the emergency room. However, recent studies suggest spacers may be better than nebulizers for children and shorten the time spent in emergency rooms. Studies also indicate that with the use of a face mask and a spacer, the MDI works well even for infants in the emergency room and may prove to be useable at home.

Click the icon to see an illustrated series detailing a metered dose inhaler.

Breath-Actuated Inhalers. Breath-actuated rotary inhalers (Easi-Breathe and Autohaler) deliver the drug directly to the back of the throat as the user inhales. Their primary advantage over the MDI is their ease of use. They also do not use CFCs as propellants. In comparison studies, patients have been very successful with the breath-actuated inhalers. They are not recommended for children under 8 years old.

Dry Powder Inhalers. Dry powder inhalers (DPIs) deliver a powdered form of beta2-agonists or corticosteroids directly into the lungs. Such devices include Rotahaler, Spinhaler, Turbohaler, Clickhaler, Easyhaler, Diskhaler, Discus, Twisthaler, Spiros, and others. DPIs are as effective as the older devices, and generally have a better taste and are easier to manage. They may differ among themselves, however, in their ability to deliver drugs into the airways. In one study, for example, the Turbohaler was easier to use than the Diskhaler and so achieved better delivery.

Humidity or extreme temperatures can affect DPIs' performance, so they should not be stored in humid places (bathroom cabinets) or locations subject to high temperatures (glove compartments during summer months).

Dry-powder may cause tooth erosion. Children are advised to rinse their mouths out right after using these inhalers and to brush twice a day with a fluoride toothpaste.

Other Hand-Held Inhalers. Respimat delivers a fine-mist spray that is created by forcing the liquid medication through nozzles. It does not use any propellant.

Nebulizers. A nebulizer is a machine that delivers a fine spray of medication-containing liquid. Nebulizers are often used for children younger than 3 years and sometimes for older children who have difficulty using the MDI. It takes 5 - 10 minutes to administer medication using a nebulizer. Because the spray is less targeted than with the inhaler, it must deliver large amounts of the drug. This increases the risk for toxicity and severe side effects. Nebulizers should not be used by children who can manage an inhaler. Their use has been associated with a higher rate of hospitalizations and longer duration of symptoms than inhalers. A 2007 study also suggested that the misuse of home nebulizers may be an important factor in asthma deaths in children and young adults. If children must use an albuterol nebulizer, parents should be sure that it does not contain the preservative benzalkonium, which actually narrows the airways.

Click the icon to see an illustrated series detailing the use of a nebulizer.

Asthma triggers a vicious emotional-physical cycle:

Breathlessness and wheezing incite a fear of suffocation and death, even in very small children.
This anxiety produces further constriction on the muscles surrounding the airways, which makes breathing even more difficult.

Caregivers must first focus on alleviating their own anxiety, which can heighten a child's own fears. The next step is to help the child relax. One method for this is as follows:

The child sits comfortably, bending slight forward with the eyes closed.
The hands are placed gently over the navel.
The child is then told to pretend the stomach is a balloon.
The "balloon" must be "blown up" by inhalation, not exhalation. The child can tell if this working because the hands will move slightly apart.
When the child breathes out, the "balloon" will be made flat.

This exercise both relaxes the child and discourages shallow, oxygen-poor breathing. Massaging the child in gentle circles on the chest is relaxing and may also loosen mucus.

Other recommendations include:

A child may also find relief by lying stomach-down on several pillows so that the head is slightly lower than the chest while the caregiver gently pats the back between the shoulder blades.
Warm liquids, such as soup or hot cider, are effective in loosening mucus and may also relax bronchial muscles. Cold fluids, like cold air, should be avoided.
Overhydration (too much liquid) can be harmful, however, so these drinks should not be forced on the child.
Warm, moist air from vaporizers can greatly ease and moderate asthma attacks.
Daily massages and breathing and relaxation techniques to reduce stress can be very helpful.

Many adults self-manage their asthma using daily monitoring of peak air flow with adjustments of the medications as needed. This involves the use of a peak flow meter, which measures peak expiratory flow rate (PEFR).

Click the icon to see an image of a peak flow meter.

Studies suggest, however, that for most children with asthma, an educational program is just as effective for managing the condition as monitoring. Most children do not need to monitor their peak air flow on any regular basis.

Quick-Relief Medications

These medications quickly control acute asthma attacks.

Beta2-agonists do not reduce inflammation or airway responsiveness but serve as bronchodilators, relaxing and opening constricted airways during an acute asthma attack. A short-acting inhaled beta2-agonist, taken as needed, is often the only medication used by children with chronic mild asthma.

Asthma is a disease in which inflammation of the airways causes airflow into and out of the lungs to be restricted. When an asthma attack occurs, mucus production is increased, muscles of the bronchial tree become tight, and the lining of the air passages swells, reducing airflow and producing the characteristic wheezing sound.

Specific short-acting beta2-agonists include:

Albuterol (Proventil, Ventolin), called salbutamol outside the U.S., is the standard short-acting beta2-agonist in America. Other similar beta2-agonists are isoproterenol (Isuprel, Norisodrine, Medihaler-Iso), metaproterenol (Alupent, Metaprel), pirbuterol (Maxair), terbutaline (Brethine, Brethaire, Bricanyl), and bitolterol (Tornalate). Isoetharine (Bronkometer, Bronkosol) is available in nebulizers.
Newer beta2-agonists, including levalbuterol (Xopenex), have more specific actions than the standard drugs. Xopenex is administered with a nebulizer, and studies have indicated that it is as effective as albuterol with fewer side effects. The original formulation of Xopenex was administered with a nebulizer. A new metered-dose inhaler formulation was launched at the end of 2005. It is approved for children age 4 years and older.

Short-acting bronchodilators are generally administered through inhalation and are effective for 3 - 6 hours. They relieve the symptoms of acute attacks, but they do not control the underlying inflammation. If asthma continues to worsen with the use of these drugs, a doctor may prescribe corticosteroids or other drugs to treat underlying inflammation.

Side Effects of Beta2-Agonists. Side effects of all beta2-agonists may include:

Anxiety
Tremor
Restlessness
Headache
Fast and irregular heartbeats. A doctor should be notified immediately if this side effect occurs.
These drugs should be taken with caution by children with diabetes or a history of seizures.
Beta2-agonists have serious interactions with certain drugs and parents should tell the doctor about any other medications their child is taking.

Loss of Effectiveness and Overdose. There has been some concern that short-acting beta2-agonists become less effective when taken regularly over time, increasing the risk for overuse. Over time, some patients may become tolerant to many effects of short-acting beta2-agonists. The degree to which this affects the airways is uncertain. In some studies, the duration of action has declined but the peak effect appears to be preserved, making these drugs still useful for acute attacks. Regular use of long-acting beta2-agonists may increase the chances of a reduced effect from the short-acting forms.

A 2005 landmark study suggested that patients’ differing clinical response to albuterol may be based on their genotype. Albuterol targets the beta-adrenergic receptor. In the Beta-Adrenergic Response by Genotype (BARGE) trial, researchers studied the effects of albuterol on patients with two different forms of this receptor. The results suggested that patients with the arginine form of the receptor did not respond to albuterol. These patients’ asthma symptoms actually improved when albuterol was not used. By contrast, patients with the glycine form of the receptor had improved asthma control with albuterol.

Inhaled ipratropium bromide (Atrovent) acts as a bronchodilator over time. Ipratropium bromide alone is only modestly beneficial for acute asthma attacks. In fact, the drug is not approved specifically for asthma. Some parents report benefit for treating wheezing in infants. It is also sometimes used in the emergency room to treat children with severe asthma to enhance the effects of intravenous beta2-agonists.

Common oral corticosteroids include prednisone/prednisolone, dexamethasone, methylprednisolone, and hydrocortisone. They reduce inflammation very effectively. A 2006 study indicated that oral prednisolone worked better than inhaled fluticasone for treating mild-to-moderate asthma attacks in children in emergency rooms. However, children often have difficulty taking these drugs because they have a bitter taste and can cause vomiting. Taking oral dexamethasone for 2 days may be as effective and more tolerable than the standard 5-day regimen of prednisone/prednisolone. Prolonged use of oral steroids has widespread and sometimes serious side effects, so they are not generally give to children for longer than a few days.

[See In-Depth Report #4: Asthma in adults.]

Long-Term Relief Medications

These medications are taken on a regular basis to prevent asthma attacks and control chronic symptoms.

Corticosteroids, also called glucocorticoids or steroids, are powerful anti-inflammatory drugs. Steroids are not bronchodilators (they do not relax the airways) and have little effect on symptoms. Instead, they work over time to reduce inflammation and prevent permanent injury in the lungs. They can also help prevent asthma attacks from occurring. Many studies have shown that the use of inhaled corticosteroids in patients with moderate-to-severe asthma significantly reduces the rate of rehospitalizations and deaths from asthma.

Inhalation of corticosteroids makes it possible to provide effective local anti-inflammatory activity in the lungs with minimal systemic effects. (By contrast, oral steroids have considerable side effects throughout the body.) Inhaled corticosteroids are recommended as the primary therapy under the following circumstances:

For any asthmatic condition more serious than occasional episodes of mild asthma. (Low-doses of inhaled steroids may even be safe and effective for some people with mild asthma, particularly those who find themselves using beta2-agonists daily.)
When treatment with bronchodilators is not effective.

Examples of inhaled corticosteroids:

Inhaled steroids include fluticasone (Flovent), budesonide (Pulmicort), triamcinolone (Azmacort and others), and flunisolide (AeroBid). In general, the newer drugs are more powerful than the older generation of inhaled drugs. Budesonide (Pulmicort Respules) is available in a jet nebulizer for children from 12 months to 8 years. It is the first such medication to be approved for children in this age group.
The FDA approved a new inhaled corticosteroid, mometasone furoate (Asmanex) was approved in 2005 for patients age 12 and older.
The older corticosteroid inhalants are beclomethasone (Beclovent, Vanceril) and dexamethasone (Decadron Phosphate Respihaler and others). They are less powerful than the newer steroids when delivered with standard inhalers. New inhalers that use very fine sprays (QVAR, Autohaler) to deliver the drugs deep into the lungs may prove to be as effective as the newer, more potent steroids.
Inhalers that combine both long-acting beta2-agonists and corticosteroids are also available. These include Symbicort (budesonide/formoterol), which was approved in 2006 for patients ages 12 years and older.

Expert guidelines recommend inhaled corticosteroids as the preferred first-line therapy for children with mild-to-moderate asthma. Nevertheless, they are still significantly underprescribed in the patients who need them most. An important 2007 study of 6 - 14 year old children with asthma compared inhaled corticosteroid therapy (fluticasone) with an inhaled corticosteroid/long-term beta2 agonist (fluticasone/salmeterol) and a leukotrine receptor antagonist (montelukast). The results indicated that fluticasone alone worked better than the other two treatments.

Researchers have been investigating whether early treatment with corticosteroids can help prevent the development of asthma in at-risk children. Two important 2006 studies in the New England Journal of Medicine suggested that while inhaled corticosteroids helped ease symptoms and reduce breathing problems in pre-school children at risk for asthma, they did not help protect against asthma development.

For now, experts caution against corticosteroids for infants and toddlers with mild asthma and urge close monitoring especially for children under age 5 with severe asthma who are receiving high doses. Because the newer potent drugs, particularly fluticasone, may produce major side effects similar to oral steroids, it is important when treating all children to aim for the lowest effective dose possible. Fortunately, studies suggest that low doses of fluticasone may achieve the same benefits as with high ones, thus reducing risks for serious side effects. Better delivery methods may also allow lower doses.

Side effects of inhaled steroids may include:

The most common side effects are throat irritation, hoarseness, and dry mouth. These effects can be minimized or prevented by using a spacer device and rinsing the mouth after each treatment.
Rashes, wheezing, facial swelling (edema), fungal infections (thrush) in the mouth and throat, and bruising are also possible but not common with inhalators.
Some children experience changes in mood, memory, and behavior. These changes are not permanent.
Some studies have suggested a higher risk for gum inflammation.
Oral steroids reduce bone density. Research reports that inhaled steroids -- both older and newer drugs -- may also affect bone growth and density. However, a number of studies report only a slight effect (about half an inch) on children's growth, which may be only temporary. It is still unknown if these drugs have any significant long-term effect on bone density. Calcium supplements may help prevent bone loss that is due to inhaled steroids.
It is not yet known whether inhaled steroids affect lung growth in very young children. Steroids administered using nebulizers are of particular concern.
There is also some concern that the stronger drugs, particularly fluticasone, suppress the adrenal system to a greater degree than other steroid inhalants. This effect, in turn, reduces levels of natural steroids -- notably cortisol, the major stress hormone. (This is a serious side effect of oral steroids).

Long-acting beta2-agonists are used in combination with inhaled corticosteroids for treating children with moderate-to-severe asthma. These drugs include include salmeterol (Serevent Diskus) and formoterol (Foradil Aerolizer). A single inhaler (Advair Diskus) that combines both salmeterol and the corticosteroid fluticasone is available for children age 4 years and older, and an inhaler (Symbicort) combining formoterol and the corticosteroid budesonide is approved for children age 12 years and older.

Long-acting beta2-agonists are used for preventing an asthma attack (not for treating attack symptoms). The effects of one dose of a long-acting beta2-agonist last for about 12 hours, so they are particularly effective during the night. These drugs also may be used for prevention of exercise-induced asthma in people and to protect against aspirin-induced asthma.

However, research indicates that long-acting beta2-agonists can worsen asthma by increasing symptom severity. These drugs may also increase the risk for asthma-related deaths. Experts are still trying to determine when long-acting beta2-agonists should be added to an asthma treatment plan. If a child’s symptoms do not improve or if symptoms worsen with this type of drug, the doctor will recommend discontinuing it. Patients should not, however, stop taking this drug or other asthma medications without first talking with their doctors.

Side Effects. Side effects of long-acting beta2-agonists are similar to the short-acting drugs.

Specific Warning on Salmeterol and Formoterol. In 2003 a "black box" warning was added to product packaging for drugs that contain salmeterol, including Serevent Diskus, and Advair Diskus. Serevent and Advair are approved for patients age 12 years and older. The warning was based on a study that demonstrated more serious and even fatal asthma episodes in patients who used the drug than in patients who used a placebo.

In 2006, the FDA updated the warning to include formoterol (Foradil Aerolizer, approved for patients 5 years and older). Warnings for salmeterol and formoterol products emphasize that these medicines can increase the risk of severe asthma episodes. Long-acting beta2-agonists require up to 20 minutes to achieve effectiveness, and there is a danger of overdose if a patient is not aware of this delay and takes additional doses to achieve faster relief. The FDA recommends that patients:

Use long-acting beta2-agonists only if other medicines (such as steroids) have not helped control asthma.
Use a short-acting bronchodilator, not a long-acting beta2-agonist, to treat sudden wheezing.
Do not use long-acting beta2-agonists to treat wheezing that is getting worse. Call your doctor if this situation occurs.
Do not stop using any asthma medicines without first talking to your doctor.

Cromolyn sodium (Intal) is both an anti-inflammatory drug and has antihistamine properties that block asthma triggers such as allergens, cold, or exercise. Cromolyn has been the anti-inflammatory drug of choice for prevention of asthma attacks in children over age 4 with chronic moderate asthma. It is not as effective as inhaled corticosteroids, however, for reducing hospitalization rates, improving symptoms, and reducing the use of beta2-agonists in children with persistent asthma. Still, cromolyn has a well-known long-term safety record, while the long-term adverse effects of corticosteroids in children are still not fully known. Many children who need asthma maintenance therapy will still do well on cromolyn. (It may not provide any real benefit for children under age 4.)

Nedocromil (Tilade) is similar to cromolyn and needs to be taken only once a day. It also prevents asthmatic reactions to cold and exercise. It is not used in very young children. A cromolyn nasal spray called Nasalcrom has been approved for over-the-counter purchase, but only to relieve nasal congestion caused by allergies. Patients should not use it for self-medication without the advice of a doctor.

Side Effects. Side effects of cromolyn include nasal congestion, coughing, sneezing, wheezing, nausea, nosebleeds, and dry throat. Nedocromil has an unpleasant taste, and some people have complained of nausea, headache, and spasms in the airways, but no serious side effects have been reported.

Leukotriene-antagonists (also called anti-leukotrienes or leukotriene modifiers) are oral medications that block leukotrienes. Leukotrienes are powerful immune system factors that, in excess, produce a battery of damaging chemicals that can cause inflammation and spasms in the airways of people with asthma. As with other anti-inflammatory drugs, leukotrienes are used for prevention and not for treating acute asthma attacks.

Leukotriene-antagonists include zafirlukast (Accolate), montelukast (Singulair), zileuton (Ziflo), and pranlukast (Ultair, Onon). These drugs are proving helpful for long-term prevention of asthma, including exercise-induced asthma and aspirin (or NSAID) -induced asthma. However, most studies to date have reported better success with inhaled corticosteroids than with the leukotriene-antagonists. A 2006 study of children with mild-to-moderate persistent asthma indicated that the corticosteroid fluticasone worked better than the leukotriene-antagonist montelukast in controlling symptoms. Nevertheless, some studies suggest that montelukast, which comes in a chewable tablet, may be particularly useful for managing asthma in small children (ages 2 - 5), since they have trouble with inhaled steroids.

Side Effects and Complications. Gastrointestinal distress is the most common side effect of leukotriene-antagonists. Very few other side effects have been reported. In general, these drugs appear to be safe and well-tolerated.

Of some concern are reports of Churg-Strauss syndrome in a few people taking zafirlukast or montelukast. Churg-Strauss syndrome is very rare, but it causes blood vessel inflammation in the lungs and can be life threatening. Oral steroids quickly resolve the problem. In fact, usually the syndrome has occurred in patients who were tapering off steroids and changing over to the leukotriene-antagonists. Some experts believe that, in such cases, the steroids may simply have masked the presence of the disorder, which then developed when the steroid drugs were withdrawn. Symptoms include severe sinusitis, flu-like symptoms, rash, and numbness in the hands and feet.

Other concerns are indications of liver injury in patients taking zileuton and zafirlukast when taken at higher than standard doses. No adverse effects on the liver have been reported to date with montelukast.

Theophylline (Theo-Dur, Theolair, Slo-Phyllin, Slo-bid, Constant-T, Respbid) is a mild-to-moderate bronchodilator that has been used to treat childhood asthma for more than 30 years. It is useful for treating nocturnal asthma and may also have anti-inflammatory qualities even in low doses.

Available in tablet, liquid, and injectable forms, some theophylline sustained-release tablets and capsules have a long duration of action and can therefore be taken once or twice a day with good results.

Side effects may include changes in behavior, mood, and memory. If theophylline is not taken exactly as prescribed, an overdose can easily occur. Toxicity can cause nausea, vomiting, headache, insomnia, and, in rare cases, disturbances in heart rhythm and convulsions. Contact a doctor immediately if any of these side effects occur.

The risks for these adverse effects are small if the drug is taken exactly as prescribed but the following precautions should be noted:

Infants tend to metabolize the drug extremely slowly and, therefore, should receive very low doses.
By the time children reach age 1, however, they metabolize the drug faster than adults. There is a risk, therefore, of toxic effects.
Fever and certain antibiotics may slow down the rate at which theophylline is eliminated from the body. In such cases, the doctor may want to reduce the dosage of theophylline.

If a child is taking theophylline on an ongoing basis, the doctor should monitor the drug level at the start of therapy and at regular intervals thereafter.

Omalizumab (Xolair) is FDA-approved for patients age 12 and older who have moderate-to-severe persistent asthma related to allergies. The first drug of this type to be approved for asthma, omalizumab is a monoclonal antibody (MAb), a genetically developed drug designed to attack very specific targets. Omalizumab is administered by injection every 2 - 4 weeks. It is used only to treat patients whose symptoms are not controlled by inhaled corticosteroids.

Omalizumab prevents the antibody immunoglobulin E (IgE) from triggering the inflammatory events that lead to asthmatic attacks. Studies have shown excellent benefits of the drug, including a reduced need for corticosteroids, fewer hospitalizations, and significant symptomatic improvements.

However, about 1 in 1,000 patients who take omalizumab develop anaphylaxis (a life-threatening allergic reaction). In 2007 the FDA requested the manufacturers of omalizumab to put a “boxed warning” on the medicine’s label emphasizing the drug’s risk for anaphylaxis. The boxed warning notes that patients can develop anaphylaxis after any dose of omalizumab, even if they had no reaction to a first dose. Anaphylaxis may occur up to 24 hours after the dose is given.

The FDA recommends that healthcare providers observe patients for at least 2 hours after an injection. Patients should also carry emergency self-treatment for anaphylaxis (such as an Epi-Pen) and know how to administer it. With an Epi-Pen, or similar auto-injector device, patients can quickly give themselves a life-saving dose of epinephrine.

Anaphylaxis symptoms include:

Difficulty breathing
Chest tightness
Dizziness
Fainting
Itching and hives
Swelling of the mouth and throat

[See In-Depth Report #4: Asthma in adults.]

Other Treatments

Alternative therapies are widely used by children, adolescents, and adults with asthma. In one study, nearly half of asthma or allergy sufferers resorted to alternative treatments. To date, however, evidence does not support most alternative therapies, including high-dose vitamins, urine injections, homeopathic remedies, and most herbal remedies.

Relaxation and Stress-Reduction Techniques. Patients report benefits from many stress reduction and physical techniques, such as acupuncture, hypnosis, breathing relaxation techniques, the Alexander technique, massage therapy, and meditation practices. There have been very few well-conducted studies supporting their use, however.

Acupuncture, hypnosis, and biofeedback are alternative ways to control pain. Acupuncture involves the insertion of tiny sterile needles, slightly thicker than a human hair, at specific points on the body.

Breathing Exercises. Some studies have suggested that breathing exercises or training may be helpful. A number of different methods are available. One example is the Buteyko breathing method, an experimental approach designed to increase levels of carbon dioxide in the body. To do this, patients are trained to reduce their volume of breath and to avoid hyperventilation (over-breathing). Some studies report that patients using this method reduce their use of medications and improve their quality of life. The system originated in Australia and is not yet widely available in the U.S.

Probiotics. Probiotics are beneficial bacteria that may possibly help protect against allergies and asthma. Antibiotic overuse and modern hygiene may specifically be reducing these helpful organisms. Look for probiotics in active yogurt cultures and in supplements, which are being studied for protection.

Herbal Remedies. Butterbur (also known as Petasites hybridus, butter dock, blatterdock, bog rhubarb, and exwort), is a traditional herbal remedy used for seasonal allergies and asthma. In a 2002 study, it was as effective and less sedating than a commonly prescribed antihistamine for treating seasonal allergies over a 2-week period. However, little research exists on its effect on asthma. Overall, there is scant evidence supporting the benefits of herbs and nutritional supplements for asthma control.

Managing Asthma

The more allergies a child has, the more severe the asthma. Making lifestyle changes to reduce allergy attacks and other triggers is extremely important.

House dust is a reservoir for pollen and dust mites. Some experts believe that reducing household allergens and pollutants in the home could reduce asthma in children by 40%.

Controlling for Dust. Spray furniture polish is very effective for reducing both dust and allergens. Air cleaners, filters for air conditioners, and vacuum cleaners with High Efficiency Particular Air (HEPA) filters can help remove particles and small allergens found indoors. Neither vacuuming nor the use of anti-mite carpet shampoo, however, is effective in removing mites in house dust. Vacuuming actually stirs up both mites and cat allergens. If possible, avoid carpets and rugs.

Click the icon to see an image of a HEPA air filter.

Bedding and Curtains. Many experts recommend reducing exposure to dust mites by enclosing mattresses and pillows in semipermeable coverings. (Vinyl mattress covers limit airflow and may also worsen, or even cause, asthma in children. Synthetic pillows may pose a significantly higher risk for severe asthma attacks in children than feather or no pillows.) However, several 2005 studies suggested that such covers do not prevent asthma or allergies. Replace curtains with shades or blinds, and wash bedding using the highest temperature setting.

Click the icon to see an image of dust mite prevention.

One study found that children sleeping in bottom bunk beds are significantly more likely to develop asthma than siblings occupying the upper bunks. Families with children who have asthma or allergies should avoid bunk beds or be sure that children with asthma sleep in the top bunk. Even with standard beds, it may be useful to have them sleep as high off the floor as possible.

Exterminating Pests (Cockroaches and Mice). Use professional exterminators to eliminate cockroaches. (One study reported that ridding a home of cockroaches and cleaning the house using standard housecleaning techniques failed to eliminate the cockroach allergens themselves.) Exterminate mice, and attempt to remove all dust, which might contain mouse urine and dander.

Reducing Humidity in the House. Although warm, moist air from vaporizers can greatly ease and moderate asthma attacks, living in a damp house is counterproductive. Dust mites thrive in humidity and damp houses increase the risk for mold, so on-going humidifiers can be unhelpful. If they are used, humidity levels should not exceed 40%, and humidifier should be cleaned daily with a vinegar solution.

Controlling Pets. People with asthma who already have pets and are not allergic to them probably have a low risk for developing such allergies later on. When children are exposed to more than one dog or cat during their first year, they have a much lower risk for allergies and asthma.

For children who have an existing allergy to pets, however, the pets should be given away or kept outside. If this isn't possible, they should at least be confined to carpet-free areas outside the bedroom. Cats harbor significant allergens, which can even be carried on clothing; dogs usually present fewer problems. Washing animals once a week can reduce allergens. Dry shampoos, such as Allerpet, are now available for both cats and dogs to remove allergens from skin and fur and are easier to administer than wet shampoos.

Many of the same substances trigger both allergies and asthma. Common allergens include pollen, dust mites, mold and pet dander. Other asthma triggers include irritants like smoke, pollution, fumes, cleaning chemicals, and sprays. Asthma symptoms can be substantially reduced by avoiding exposure to known allergens and respiratory irritants.

Preventing Exposure to Cigarette and Cooking Smoke. Parents who smoke are strongly urged to quit. Studies indicate that exposure to second-hand smoke in the home increases the risk for asthma and asthma-related emergency room visits in children. Even smoky cooking can worsen asthma.

Parental smoking has been shown to increase the airway responsiveness of infants as early as the first 2 - 10 weeks of life. This extends even to the fetus of pregnant women who smoke. Such mothers tend to have babies born at a low birth weight, which affects lung function and increases babies' risks for asthma.

Avoiding Outdoor Allergens. The following are some recommendations for avoiding allergens outside:

Avoid scheduling camping and hiking trips during times of high pollen count (generally, May and June for grass pollen and mid-August to October for ragweed).
Patients should avoid strenuous activity when ozone levels are highest, which usually occur in early afternoon, particularly on hot hazy summer days. Levels are lowest in early morning and at dusk.
Asthma attacks are often higher during thunderstorms. Some evidence points to a build-up of ozone that accompanies such storms. Other evidence suggests that the changing airflow patterns bring a sudden downdraft of air containing concentrations of pollens, small particles and allergens.
Patients who are allergic to mold should avoid barns, hay, raking leaves, and mowing grass.
Exposure to automobile fumes may worsen asthma. Fungi in car air conditioners can also be a problem.

Reducing Exposure to Air Pollution. Children breathe faster than adults, taking in more pollutants, and therefore are particularly susceptible to soot and other small particles in the air. A 2001 study found an association between higher rates of asthma and other health problems in children who were exposed to high levels of specific pollutants (particularly sulfur dioxide and nitrogen dioxide). Diesel fuel exhaust has also been associated with worsening asthma in children.

Some experts point out that asthma rates in North America have increased over recent years while the prevalence of many common air pollutants have declined. So pollution is unlikely to be a primary cause of asthma. Regardless of whether pollution is an important cause of asthma, evidence strongly suggests that it can affect existing asthma.

Patients with asthma and chronic allergic rhinitis may require daily medications. Patients with severe seasonal allergies may be advised to start medications a few weeks before the pollen season, and to continue it until the season is over.

Immunotherapy ("allergy shots") may help reduce asthma symptoms, and the use of asthma medications, in patients with known allergies. They may also help prevent the development of asthma in children with allergies. Immunotherapy poses some risk for severe allergic reactions, especially for children with poorly controlled asthma, so it is important that the doctor carefully evaluates the child’s asthma condition.

[See In-Depth Report #77: Allergic rhinitis.]

Weight Loss. Children who are both asthmatic and overweight may reduce asthma symptoms simply with weight loss.

Fruits, Vegetables, and Whole Grains. Healthy foods are important for lung function. Specific foods that may be important for healthy lungs contain antioxidants (deep green and yellow-orange fruits and vegetables), selenium (fish, red meat, grains, eggs, chicken, liver, garlic), plant chemicals called flavonoids (apples, onions), and magnesium (green leafy vegetables, nuts, whole grains, milk, and meats).

Fish Oil. Omega-3 fatty acids, found in cold water oily fish and in supplements (preferably DHA-EPA, the important compounds in fish oil) have anti-inflammatory effects. Some evidence suggests they may be helpful for people with asthma.

Caffeine. Caffeine has properties that are similar to the asthma drug theophylline. A major analysis of studies reported that caffeine improved lung function for up to 4 hours after consumption. Although tea and coffee are the major sources of caffeine, some sodas contain it and should be avoided when children have an asthma attack. (People who are going to have their lung function tested should avoid drinking coffee, tea, or other caffeinated beverages for at least 4 hours beforehand.)

Food Allergies. Although about 70% of people with asthma believe their symptoms are aggravated by food allergies, studies indicate that this belief may be true in only 5% of cases. If young children show signs of or test positive for food allergies, however, parents should be extra cautious in preventing exposure to any asthma trigger. Some doctors now counsel all children with asthma to avoid nuts entirely, and, of course, children who experience reactions to any foods should avoid them.

Chemicals that may pose some risk for an allergic reaction are monosodium glutamate, or MSG (found in some canned soups, cheese, and certain vegetables), and sulfites (preservatives in foods, such as frozen potatoes and tuna). Contrary to what many believe, dairy products do not appear to worsen asthma symptoms in people who are not already allergic to them.

Asthma is no reason to avoid exercise. Historically, about 10% of Olympic athletes have asthma. Some studies indicate that long-term exercise may help control asthma and reduce hospitalization.

Encourage children with asthma to swim and play sports, such as baseball, that will present less difficulty for them. Intense activities lasting less than 2 minutes, such as sprinting or competitive swimming, may cause fewer problems than longer-lasting exercises.

Young people who enjoy running should probably choose an indoor track to avoid pollutants. Swimming is excellent for people with asthma. Yoga practice, which uses both stretching, breathing, and meditation techniques, may have particular benefits. One study reported that two-thirds of patients who practiced yoga regularly were able to reduce or stop taking their asthma medications.

Patients should consult their doctors before starting any exercise program. Exercise-induced asthma is a limited condition that has specific recommendations.

People with asthma should try to minimize their risk for respiratory tract infections. Washing hands is a very simple but effective preventive measure.

Patients with asthma should ask their doctor about getting the influenza ("flu") vaccine and also whether they should receive the vaccination against pneumococcal pneumonia.

Zanamivir, a new drug used for treating influenza, is considered safe for patients with asthma 12 years of age or older. In one study, patients with asthma treated with zanamivir experienced fewer flu symptoms, and their lung function improved.

People with asthma have no higher rate of anxiety or depression than the general population. However, such emotions interact with the effects of asthma and its treatments in important ways:

Negative emotions can discourage compliance with medication and the ability to cope.
Poor control of asthma symptoms, in turn, increases the risk for negative emotions.
Stress and depression have been associated with more severe symptoms and even an increased risk of fatal asthma attacks.

Some evidence suggests that stress reduction techniques, a positive attitude, and relaxation techniques may be very helpful in the long-term management of asthma.

Resources

www.lungusa.org -- The American Lung Association
www.acaai.org -- American College of Allergy, Asthma & Immunology
www.aaaai.org -- American Academy of Allergy, Asthma, and Immunology
www.nhlbi.nih.gov -- National Heart, Lung, and Blood Institute
www.asthma-carenet.org -- Childhood Asthma Research and Education Network
www.njc.org -- National Jewish Center for Immunology and Respiratory Medicine
www.aafa.org -- Asthma and Allergy Foundation of America
www.aanma.org -- Allergy and Asthma Network, Mothers of Asthmatics

References

Akinbami L; Centers for Disease Control and Prevention National Center forHealth Statistics. The state of childhood asthma, United States, 1980-2005. Adv Data. 2006 Dec 12;(381):1-24.

Bisgaard H, Hermansen MN, Loland L, Halkjaer LB, Buchvald F. Intermittent inhaled corticosteroids in infants with episodic wheezing. N Engl J Med. 2006 May 11;354(19):1998-2005.

Cates CJ, Crilly JA, Rowe BH. Holding chambers (spacers) versus nebulisers for beta-agonist treatment of acute asthma. Cochrane Database Syst Rev. 2006 Apr 19;(2):CD000052.

Douwes J, van Strien R, Doekes G, Smit J, Kerkhof M, Gerritsen J, et al. Does early indoor microbial exposure reduce the risk of asthma? The Prevention and Incidence of Asthma and Mite Allergy birth cohort study. J Allergy Clin Immunol. 2006 May;117(5):1067-73.

Guilbert TW, Morgan WJ, Zeiger RS, Mauger DT, Boehmer SJ, Szefler SJ, et al. Long-term inhaled corticosteroids in preschool children at high risk for asthma. N Engl J Med. 2006 May 11;354(19):1985-97.

Haland G, Carlsen KC, Sandvik L, Devulapalli CS, Munthe-Kaas MC, Pettersen M, et al. Reduced lung function at birth and the risk of asthma at 10 years of age. N Engl J Med. 2006 Oct 19;355(16):1682-9.

Marks GB, Mihrshahi S, Kemp AS, Tovey ER, Webb K, Almqvist C, et al. Prevention of asthma during the first 5 years of life: a randomized controlled trial. J Allergy Clin Immunol. 2006 Jul;118(1):53-61.

National Asthma Education and Prevention Program Expert Panel Report: Guidelines for the Diagnosis and Management of Asthma Update on Selected Topics -- 2002. Rockville, MD. National Heart, Lung, and Blood Institute, US Dept of Health and Human Services; 2003. NIH publications 02-5074.

O'Byrne PM, Pedersen S, Busse WW, Tan WC, Chen YZ, Ohlsson SV, et al. Effects of early intervention with inhaled budesonide on lung function in newly diagnosed asthma. Chest. 2006 Jun;129(6):1478-85.

Salpeter SR, Buckley NS, Ormiston TM, Salpeter EE. Meta-analysis: effect of long-acting beta-agonists on severe asthma exacerbations and asthma-related deaths. Ann Intern Med. 2006 Jun 20;144(12):904-12.

Schuh S, Dick PT, Stephens D, Hartley M, Khaikin S, Rodrigues L, Coates AL. High-dose inhaled fluticasone does not replace oral prednisolone in children with mild to moderate acute asthma. Pediatrics. 2006 Aug;118(2):644-50.

Sorkness CA, Lemanske RF Jr, Mauger DT, Boehmer SJ, Chinchilli VM, Martinez FD, et al. Long-term comparison of 3 controller regimens for mild-moderate persistent childhood asthma: the Pediatric Asthma Controller Trial. J Allergy Clin Immunol. 2007 Jan;119(1):64-72.

Review Date:
3/26/2007
Reviewed By:
Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.

A.D.A.M. Copyright

adam.com

What Do You Know About Maltese?

PetSugar — Tue, 16 Sep 2008 03:00:08 -0700

My new favorite show Greatest American Dog ended this week and while little Andrew didn't take the top spot, the judges said he was the "most incredible Maltese" they have ever witnessed.

Andrew was the highest scoring dog in trial at the annual Town and Country Kennel Club Show and was named the top Maltese in the U.S. Novice Rally Competition so clearly he's a winner of sorts even though he isn't America's greatest. What do you know about his breed? Take this quiz and find out!

Photo courtesy of CBS

Take the quiz

Viral encephalitis

FitSugar — Wed, 08 Oct 2008 17:35:12 -0700

In This Report

Highlights
Introduction
Causes
Symptoms
Risk Factors
Prognosis
Diagnosis
Treatment
Vaccinations
Prevention
Resources
References

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

West Nile Virus

In 2007, 3,510 cases of West Nile virus were reported to the U.S. Centers for Disease Control. States with the highest number of reported cases included Colorado, California, and North Dakota. Of the reported cases, two-thirds were in the form of West Nile fever, and one-third were diagnosed as West Nile neuroinvasive disease (encephalitis and meningitis). However, the high proportion of neuroinvasive disease cases is due to the fact that serious cases of West Nile virus are more likely to be reported to health authorities than mild cases. In general, less than 1% of people who become infected with West Nile virus develop encephalitis.

West Nile Virus Symptoms and Diagnosis

Most people (80%) who are infected with West Nile virus do not have any symptoms. About 20% of people develop mild symptoms that include fever, headache, body aches, and nausea and vomiting. These symptoms can last from a few days to a few weeks. For the minority of people who develop neuroinvasive disease, symptoms can include high fever, headache, neck stiffness, muscle weakness, and convulsions. While West Nile neuroinvasive disease is rare, its neurological complications such as paralysis can be permanent.

Prevention

West Nile virus is carried by mosquitoes and is most common during the summer and early fall. The best way to prevent becoming infected with West Nile virus is to avoid being bitten by a mosquito. Use insect repellant when you go outside, especially during the peak mosquito hours of dusk and dawn. Remove mosquito-breeding environments (such as standing water in flower pots) from your property. Scientists are testing several different vaccines to protect against West Nile virus, but it will be many years before they are commercially available.

Introduction

Encephalitis is a rare but potentially life-threatening inflammation of the brain that can occur in people of all ages. The most common cause of encephalitis is infection by a virus. In very rare cases, encephalitis can also be caused by bacterial infection, parasites, or complications from other infectious diseases. This report focuses on viral encephalitis.

Many viruses can cause encephalitis. The West Nile virus, for example, has been responsible for high-profile outbreaks in the U.S. Most people exposed to encephalitis-causing viruses have no symptoms. Others may experience a mild flu-like illness, but do not develop full-blown encephalitis.

In severe cases, the infection can have devastating effects, including:

Swelling of the brain (cerebral edema)
Bleeding within the brain (intercerebral hemorrhage)
Nerve damage

The damage may cause long-term cognitive or physical problems, depending on the specific areas of the brain affected.

Other Viral Infections of the Central Nervous System. Viral infection and inflammation can affect multiple areas of the central nervous system, and is categorized by its location:

Meningitis: infection of the meninges (the membranes that surround the brain and spinal cord)
Meningoencephalitis: infection of both the brain and meninges
Encephalomyelitis: infection of the brain and spinal cord

Encephalitis caused by viruses in the United States generally fall into the following groups:

Arboviruses are the primary cause of acute encephalitis (sudden-onset encephalitis caused by direct infection). Arboviruses, short for "arthropod-borne viruses," are spread by mosquitoes and ticks.
Enteroviruses, such as coxsackievirus.
Herpes viruses are the other major cause of encephalitis in the U.S. This virus family includes herpes simplex, Epstein-Barr, cytomegalovirus, and varicella-zoster.
In rare cases, secondary encephalitis can develop following childhood viral diseases such as measles, mumps, and rubella.

[For more information, see the Causes section in this report.]

Encephalitis can develop shortly after an initial viral infection, or it can develop when a virus that was lying dormant in the body suddenly reactivates. Viruses are simple, but powerful infectious organisms.

The virus infects a person (host) by penetrating a cell membrane and ejecting its genetic material (its DNA or RNA) into the cell.
The viral DNA or RNA takes control of important cell processes, telling the cell to make more viruses.
The cell ruptures, releasing new viral particles that infect other cells.

There are two ways that viruses can infect brain cells:

The virus silently invades the body. There are no initial symptoms. The virus is carried by the bloodstream to the nerve cells of the brain, where they gather and multiply. Viruses that enter the brain in this manner are often widely scattered throughout the brain. This is called diffuse encephalitis.
A virus first infects other tissue and then invades brain cells. Viruses that are transmitted from other tissues usually cause focal infection, meaning they produce extensive damage in only a small area of the brain.

The brain and spinal cord comprise the central nervous system. The adult human brain weighs about 3 pounds (1.4 kilograms). There are two major parts of the brain:

The higher and larger forebrain (the cerebrum)
The lower and smaller brain stem

The cerebrum is the uppermost and largest part of the brain. It is the most highly developed section of the brain. There cerebrum has several components:

The Cerebral Cortex. The cortex is the outermost layer of the cerebrum. It is made of gray and white matter:

Gray matter is a thin sheet of nerve cells that cover the surface of the brain.
White matter is a bundle of insulated nerve fibers that underlies the cortex and makes up the core of the cerebral hemispheres.

The Hemispheres. The two hemispheres control higher brain functions, such as memory, learning, decision making, and processing input from the senses. They are each divided into four lobes, which regulate different brain functions:

Frontal lobe: This is the brain's "gatekeeper." It controls higher motor functions, including speech, and governs concentration, attention, inhibition, judgment, and personality traits.
Parietal lobe: Processes information from the senses and controls walking, posture, and head and eye movements.
Occipital lobe: Responsible for interpreting visual input from the eyes.
Temporal lobe: Responsible for interpreting auditory input from the ears. Also regulates how language is interpreted and retrieves information for memory storage.

The Basal Ganglia. The basal ganglia are clusters of gray matter within each of the lobes. They are important for coordinating voluntary muscle movement, balance, and posture.

The Limbic System. The limbic system is located deep in the cerebrum and controls interpretation of smell, instinctive behavior, emotions, and drives.

The brain stem is responsible for all vital functions. It is divided into the following areas, which are responsible for specific functions:

Medulla: sleep, breathing, heartbeat, digestion, activation of higher forebrain functions
Pons: sleep, breathing, motor control, activation of higher forebrain functions
Cerebellum: movement coordination
Midbrain: walking, posture, head, eye movement
Hypothalamus: body temperature, appetite, sexual behavior, reproductive hormones
Thalamus: communication with higher forebrain

The spinal cord extends out of the base of the skull through the vertebrae of the spinal column. It is continuous with the brain. Thirty-one pairs of nerves extend from the sides of the spinal cord to other parts of the body (the peripheral nervous system).

The meninges are three membranes that enclose the brain and spinal cord. They contain cerebrospinal fluid, which protects the central nervous system from pressure and injury.

Causes

Arboviruses

Arboviruses, including the West Nile virus, are transmitted by blood-sucking insects such as mosquitoes and ticks. Most of the time, the viral infections initially develop in birds. Insects that feed on the infected blood from a diseased bird (or reservoir ) carry the virus, and transmit it when they bite a susceptible host (such as an animal or a human). Because these insects play a role in the disease-transmission process, they are referred to as vectors.

Arboviruses multiply in blood-sucking vectors, nearly always mosquitoes. There is no evidence that these infections can be transmitted casually from one infected person or animal directly to another uninfected person without passing through a mosquito (or tick) first. (Although, a small number of West Nile virus cases have occurred through blood transfusions, organ transplantation, and possibly breast-feeding.) It should be stressed that only about 10% of people who are infected by an arbovirus develop encephalitis and that only about 1% of those infected show symptoms.

Arboviruses that cause encephalitis are primarily found in three virus families: Togaviridae, Bunyaviridae, and Flaviviridae. In the United States, the main mosquito-borne encephalitis strains are: Eastern equine, Western equine, St. Louis, La Crosse, and West Nile. Equine encephalitis causes disease in both humans and, as its name implies, horses. Powassan encephalitis is a less common tick-borne flavivirus that occurs primarily in the northern United States. Japanese encephalitis is the most common form of viral encephalitis to occur outside of the United States. It is endemic in rural areas in east, south, and southwest Asia, especially China and Korea. Venezuelan equine encephalitis is found in South and Central America.

Different arboviruses cause different forms of encephalitis. Although the overall disease is the same, there are subtle differences in symptoms and the type of brain damage they produce.


Eastern Equine Encephalitis
Virus Family	Togaviridae (genus Alphavirus)
U.S. Geographic Areas	Atlantic and Gulf coasts, in New England, and around the Great Lakes. States most affected are Florida, Georgia, Massachusetts, and New Jersey.
Symptom Onset	Symptoms appear 4 - 10 days following infection and can range from mild flu-like symptoms to full-blown encephalitis.
Incidence and Mortality Rates	The most serious of the U.S. arboviruses are fortunately rare. About 220 cases have been confirmed since 1964 with an average rate of 5 cases per year. About a third of people who contract EEE die from it. Children are more likely to survive but also to suffer complications afterward.
Age Risk Groups	Adults over age 50 and children under age 15.
Western Equine Encephalitis
Virus Family	Togaviridae (genus Alphavirus)
U.S. Geographic Areas	Farming areas in western and central Plains and Rocky Mountain states west of the Mississippi.
Symptom Onset	5 - 10 days following infection.
Incidence and Mortality Rates	Very rare. There was only one case reported between 1995 and 2000. Mortality rate is 3 - 4%; 30% of survivors have complications afterward. Most severe in children, especially those younger than 1 year. Infants may suffer permanent neurological damage.
Age Risk Groups	Infants younger than 12 months.
St. Louis Encephalitis
Virus Family	Flaviviridae (genus Flavivirus)
U.S. Geographic Areas	Takes its name from an epidemic in St. Louis, but outbreaks have occurred in wider geographic areas, especially in midwestern and southeastern states, and can occur in rural or urban areas. As of 2000, the highest numbers of total cases have been reported in Texas (970), Illinois (695), Ohio (440), Indiana (368), and Florida (379).
Symptom Onset	7 - 10 days following infection.
Incidence and Mortality Rates	Although over 4,500 cases have been reported since 1964, the average number of cases has been declining with a yearly average of only 11 cases between 1995 and 2000. Mortality rate of between 3 - 30%, with about 5% of survivors suffering complications afterward.
Age Risk Groups	Elderly adults (over age 60) are at highest risk, and the disease is most severe in this age group. Younger people usually experience mild, flu-like symptoms.
La Crosse Encephalitis
Virus Family	Bunyaviridae (genus Bunyavirus)
U.S. Geographic Areas	Occurs most frequently in upper Midwestern, southeastern (Appalachia), and mid-Atlantic states. Most cases have occurred in Ohio and Wisconsin. Unlike other encephalitis viruses which originate in birds, La Crosse encephalitis is transmitted to mosquitoes from infected chipmunks and squirrels.
Symptom Onset	5 - 10 days following infection.
Incidence and Mortality Rates	An average of 70 - 100 cases reported per year. Mortality rates are less than 1%. More common and severe in children under age 16.
Age Risk Groups	Children younger than 16 years.
West Nile Encephalitis
Virus Family	Flaviviridae (genus Flavivirus).
U.S. Geographic Areas	Cases have been reported throughout the mainland United States. In 2007, the majority of West Nile encephalitis cases occurred in Colorado, California, and North Dakota.
Symptom Onset	3 - 14 days following infection.
Incidence and Mortality Rates	In 2007, 3,510 cases of WNV were reported to the CDC, with 109 deaths. Of all the reported cases, 65% were due to West Nile fever. A third of those who contracted WNV had more severe conditions, such as meningitis and encephalitis. However, most cases of West Nile virus do not produce symptoms, and are not reported, so these numbers imply a more worrisome picture than actually exists. In fact, fewer than 1% of people who are infected with WNV go on to develop neurological disease.
Age Risk Groups	Adults over age 50.

West Nile Virus (WNV). Until 1999, the West Nile virus was generally restricted to Africa, the Middle East, southwestern Asia, eastern Europe, and Australia. It emerged in the United States with the first outbreak in New York City in 1999. WNV is now found in birds and mosquitoes in every state except Alaska and Hawaii. Human cases of West Nile encephalitis have been reported throughout the continental United States.

How WNV Is Transmitted. WNV, discovered in Uganda in 1937, circulates primarily between birds and mosquitoes and can be carried long distances by migrating birds. In a given geographic area, the appearance of the virus among birds and mosquitoes generally precedes infection in humans. WNV has infected over 110 species of birds. In addition to mosquito-to-human transmission, other causes of human infection have included blood transfusions and organ transplantation. The U.S. now uses screening tests to detect West Nile virus in donated blood and organs. There have also been cases of mother-to-child transmission during pregnancy. However, a 2006 study reported that most pregnant women who are infected with WNV deliver healthy babies. It is still not clear if WNV can be transmitted through breast milk.

Severity of WNV. About 80% of people infected with WNV will not have any symptoms. Twenty percent will develop West Nile fever (which includes fever, headache, and occasional skin rash). Less than 1% of infected people will develop neuroinvasive disease, the most severe form of WNV.

Neuroinvasive disease affects the nervous system and includes encephalitis, meningitis, and poliomyelitis. People over age 50 and those with weakened immune systems are at the greatest risk for neuroinvasive disease. The fatality rate for those afflicted ranges from 3 - 15%. Neuroinvasive disease symptoms include high fever, headache, stiff neck, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis. Preliminary research is currently being conducted on vaccines to prevent WNV and antiviral drugs to treat it.

Although West Nile fever is considered to be less serious than West Nile neuroinvasive disease, an important 2006 study found that both conditions can cause long-term health complications. Researchers found that more than a year after being diagnosed with WNV, half of patients complained of neurological and psychological symptoms, including fatigue, memory problems, headaches, depression, and tremors. Patients who had West Nile fever were as likely to experience these problems as those who had WNV-associated encephalitis or meningitis.

Tick-borne encephalitis (TBE) is commonly found in many countries throughout Europe, Asia, and the former Soviet Union, but it is reported only rarely in the U.S. Powassan encephalitis is the main tick-borne encephalitis found in the United States and Canada. Cases of tick-borne encephalitis have also been reported from Rocky Mountain spotted fever, but this is a bacterial (not viral) infection.

Enteroviruses include various viruses that enter the body through the gastrointestinal tract. They account for between 10 - 20% of viral encephalitis cases. The group A coxsackievirus has been detected in infants and children with encephalitis and is among the important viruses in the class. (It should be noted that the enteroviruses are nearly as common as cold viruses and are rarely serious.) Enteroviruses can be spread through food or water contaminated by trace amounts of fecal material and through sneezing and coughing.

The herpes virus group includes a number of common infections, including herpes simplex, varicella-zoster (the cause of chickenpox and shingles), cytomegalovirus, herpes virus 6, and Epstein-Barr (EB) virus (the cause of mononucleosis). About 2,100 people are hospitalized each year from herpes-associated encephalitis. These viruses share certain features, including the capacity to cause an infection and then to go into hiding. They can lie dormant for periods of time as short as months or as long as a lifetime. In a few cases, when the viruses reactivate, they cause encephalitis. In fact, some evidence suggests that varicella-zoster, cytomegalovirus, and Epstein-Barr (EB) virus may be more common causes of encephalitis than previously thought. In most cases, however, encephalitis from these viruses occurs in people with impaired immune systems, such as people with HIV or organ transplant patients.

Herpes Simplex Virus. Herpes simplex virus (HSV) is the most common cause of encephalitis in developed countries and is responsible for about 10 - 20% of all adult cases of viral encephalitis. There are two distinct types of the herpes simplex virus: HSV-1 (commonly associated with oral herpes) and HSV-2 (which usually causes genital herpes, although HSV-1 can also cause this form). HSV-2 causes 70 - 90% of encephalitis cases in neonatal infants; the virus is transmitted through the mother's genital secretions. Although HSV-1 is the primary culprit in most adult cases of herpes encephalitis, HSV-2 may also cause a small number of these cases.

Herpes simplex encephalitis is the only effectively treatable form of encephalitis, but treatment (typically intravenous acyclovir) must be administered within the first few days of symptom onset. If left untreated, the mortality rate for patients with HSV-1 is about 70%; if treated, the mortality rate declines to 30%. The mortality rate for neonatal HSV-2 encephalitis ranges from 15 - 57%. [For more information, see In-Depth Report #52: Herpes simplex.]

Varicella-Zoster Virus. The varicella-zoster virus is responsible for both chickenpox (when the virus is called varicella) and shingles (when it is referred to as herpes zoster ). Chickenpox is the initial infection, after which the virus remains dormant, often for a lifetime. If it erupts, usually years later, is does so in the form of shingles. Encephalitis caused by varicella can occur in both children and adults and be very serious. If it occurs as a result of herpes zoster in adults, the brain inflammation tends to be mild, except in immunocompromised patients. In such cases, symptoms can appear weeks to months after an attack of shingles and resemble those of a stroke. Fortunately, encephalitis is rare with both varicella and zoster. [For more information, see In-Depth Report #82: Shingles and chickenpox (varicella-zoster virus).]

Epstein-Barr Virus. Epstein-Barr virus is the cause of infectious mononucleosis, which is most common in children and young adults. Symptoms of the disease are severe fatigue, headache, sore throat, and fever. In 1% of cases, neurological complications occur about 1 - 3 weeks after the onset of the infection. If encephalitis develops, it is almost always mild with full recovery.

Cytomegalovirus Encephalitis. Cytomegalovirus is also very common and usually mild. In immunocompromised patients, such those with AIDS, it can be dangerous, with severe complications including encephalitis.

Rabies. The rabies virus is transmitted from the saliva of an infected animal. The encephalitis it causes is virtually always fatal but is very rare in the U.S. Only one or two cases are typically reported each year, often from contact with bats.

Encephalitis Associated with Childhood Diseases. Encephalitis occurs rarely after common childhood infections, such as rubella, measles, and mumps. Immunizations have almost completely eliminated these infections in developed countries. Measles encephalitis still sometimes occurs in immunocompromised children. Rarely, influenza has caused acute encephalitis, usually in children. (Flu vaccinations are important in preventing these events.) Although there used to be concern that diphtheria-pertussis-tetanus and measles-mumps-rubella vaccines could cause encephalitis, recent research indicates that these childhood vaccines are very safe and do not increase encephalitis risk.

Adenoviruses. Adenoviruses were first identified in 1953 from infected tonsils and adenoids. The viruses can cause respiratory or gastrointestinal infections that are usually mild. In rare cases, adenoviruses can cause encephalitis or meningoencephalitis, which can be fatal in 30% of patients. Symptoms include lethargy, confusion, coma, and symptoms of meningitis (stiff neck, headache, and vomiting).

Toxoplasmosis. Encephalitis from toxoplasmosis, which is transmitted in a cat's fecal matter, results in 2,100 hospitalizations a year, which rivals herpes as the most common infectious cause of encephalitis. However, this condition causes very mild symptoms in most people. People with HIV and impaired immune systems are at risk for more severe forms. In addition, the effects on the fetus in a pregnant women infected with toxoplasmosis can be devastating. It can be treated with antibiotics, particularly those that treat parasites.

Raccoon Roundworm. Raccoon roundworm (Baylisascaris procyonis) is a large parasitic worm that lives in the intestines of raccoons. In one Wisconsin study, half the raccoons tested were infected. Humans usually become infected by ingesting the worm's eggs through accidental contact with soil, wood chips, or tree bark contaminated with raccoon feces. The worm is harmless in raccoons but can produce severe central nervous system disease, including encephalitis, in people. At least 12 severe cases have been reported in the U.S. since 1981, most in children younger than 6 years of age (who are at higher risk because of their tendency to put their fingers or other objects into their mouths). Prompt treatment with larvae-killing drugs, such as albendazole, or anti-inflammatory drugs is not consistently effective, so it is extremely important to avoid infection. Raccoons should not be kept as pets. Eliminate access to food sources, like garbage cans and bird feeders, which will attract raccoons. Raccoon nests should be sealed off while raccoons are absent. Burning any contaminated materials is the most effective method of disposal. If burning is not feasible, contaminated substances should be buried deeply in a location remote from human activity. Wearing disposable gloves, boots, and a dust mask is important. Decks, woodpiles, and other surfaces can be decontaminated with boiling water.

Other Parasitic Infections. Encephalitis may be caused by other parasitic infections, such as toxocariasis (from roundworms found in dogs and cats) or cysticercosi (from food or water contaminated with pork tapeworm eggs). These infections usually cause only chills, fever, and swelling of lymph nodes, though seizures and headaches can occur.

In very rare circumstances, encephalitis may be caused by bacterial or fungal organisms.

Acute disseminated encephalomyelitis (ADEM), also called noninfectious encephalitis, constitutes one-third of all known cases of encephalitis. It is not caused by a virus, although it most often develops in patients 2 - 3 weeks after recovery from a viral illness. (It does not affect children under 2 years old.) Damage to nerve cells in such cases is caused not by the viral infection, however, but most likely by an autoimmune reaction, in which the body's immune system attacks its own brain tissue.

Acute disseminated encephalomyelitis has been reported as a rare complication of childhood illness, including chickenpox, mumps, or measles. Vaccination reduces these risks to nearly insignificant levels. It is a complication of the rabies vaccine in one out of 30,000 cases. Nonspecific respiratory infections are now the most common causes of ADEM, but such cases are also extremely rare.

The inflammation occurs predominantly in the white matter of the brain rather than the gray matter (the usual target of infectious encephalitis). The nerve cells do not die as they do in a viral infection. Rather, the nerve cell coating (called a myelin sheath) is partially destroyed in much the same way as it is in multiple sclerosis. Indeed, the two conditions may at first be difficult to distinguish. Recurrences may occur several months to years after the initial episode.

Symptoms

Symptoms of encephalitis usually appear within 2 days to 2 weeks of exposure to the virus. In milder cases, symptoms may resemble the flu. In severe cases of full-blown encephalitis, symptoms may include:

Behavioral and personality changes
Sensitivity to light
Fever
Headache
Vomiting
Lethargy and reduced consciousness
Seizures -- uncommon with West Nile virus
Memory loss
Stiff neck and back -- accompanied by fever and headache would indicate meningitis
Confusion
Speech, hearing, and vision problems
Muscle weakness
Seizures
Partial paralysis
Loss of consciousness
Coma

Patients experiencing these types of symptoms (especially if they may have recently been bitten by a mosquito or tick of if they have lesions on the lips or genitals) should immediately seek medical treatment.

Symptoms in Infants. Infants with herpes virus encephalitis may develop lesions in the mouth, in the eye, or on the skin 1 - 45 days after birth. Other symptoms include lethargy, seizures, and changes in temperature. Their fontanels, the soft spots on their head where the skull has not yet closed, may bulge outward.

Risk Factors

Encephalitis is a rare disease, extremely uncommon in the U.S. even for people in the risk groups discussed below. Many people fall into the following categories; very few of them will ever contract encephalitis.

Encephalitis can occur at any age; increased age-associated risks depend on the type of encephalitis virus. Newborn infants are particularly at risk for herpes virus. For arboviruses, infants are most vulnerable to Western equine encephalitis. Older children and teenagers are more susceptible to Eastern equine and La Crosse encephalitis. Older and elderly adults are at higher risk for Eastern equine, St. Louis, and West Nile encephalitis.

Immunocompromised Patients

Patients whose immune systems are compromised by conditions such as HIV-AIDS, cancer therapies, or organ transplantation are more susceptible than other individuals to any form of encephalitis. Of particular concern are varicella and cytomegalovirus encephalitis which tend to be more common and deadly in these patients than in the normal population.

U.S. Geographic Regions. The primary risk factor for arbovirus encephalitis is living in areas of possible exposure to virus-carrying mosquitoes. Most viral outbreaks occur in rural or farming areas, but they can also occur in cities. While some forms of arbovirus encephalitis are limited to specific geographical regions, the West Nile virus has become endemic throughout the mainland United States. [See Common Forms of Mosquito-Borne Encephalitis table for more detailed regional information.]

Seasonal Risks. Transmission of arboviruses correlates with the mosquito season and is highest during the months of July through September (late summer through early fall). The ideal conditions for mosquito breeding are a wet spring followed by a hot, dry summer.

Few people in the world have not been infected with at least one of the herpes viruses. Most of these viruses are easily transmitted in body fluids, including from saliva or droplets after people exhale or sneeze. Infants can contract herpes simplex virus from an infected mother during delivery, which can have very serious consequences. [For more information, see In-Depth Report #52: Herpes simplex.]

Prognosis

In most cases of arbovirus infection, symptoms are mild, last 3 - 5 days, and resolve without becoming serious. In fact, the infection is generally unrecognized as anything other than a mild flu.

Prognosis for severe encephalitis depends on many factors, including the following:

Age of the patient -- worse outcomes for infants under age 12 months and adults over age 55
Immune status
Preexisting neurological conditions
Virulence of the virus

In severe cases of encephalitis, the swelling of the brain inside the skull places downward pressure on the brain stem. The brain stem controls vital functions, such as respiration and heartbeat, and if the pressure becomes too severe, these vital functions can cease and cause death.

Coma is a common symptom in patients with severe encephalitis, but does not necessarily predict a fatal or severe outcome. In one study of Eastern equine encephalitis, some survivors averaged 5 days in a coma and had no or only mild-to-moderate complications afterward. One patient was in a coma for 9 days and had only mild complications afterward.

Survivors of encephalitis commonly experience neurologic consequences, which can be long-term and even permanent. The degree and type of brain damage can vary from mild-to-severe and from focal (in one part of the brain) to multifocal (several parts of the brain) to diffuse (throughout the brain).

The location and severity of the infection largely determines the pattern of brain damage and therefore its effects, which can be:

Physical (muscle control)
Behavioral and emotional (personality changes)
Cognitive (memory, speech)
Sensory (vision, hearing)
Some patients who have memory problems and personality changes afterward describe their condition as being an "invisible disease." They appear to be normal to others, but they are plagued with forgetfulness and lapses in attention that have a considerable effect on the quality of their daily lives. Helpful support groups are now available on the Internet.

Diagnosis

In many cases, the symptoms of encephalitis are too similar to aid the doctor in differentiating among the many causes of brain inflammation. The primary objective in diagnosing viral encephalitis is to determine if it is caused by:

Arboviruses or other viruses that can be managed only by relieving symptoms
Herpes simplex or other conditions that are potentially treatable

If the doctor suspects encephalitis, a scanning technique is often the first diagnostic step. Computerized tomography (CT) or magnetic resonance imaging (MRI) scans may show the extent of the inflammation in the brain and help differentiate encephalitis from other conditions. MRI can detect injuries in parts of the brain that suggest infection with herpes virus at the onset of the disease, while CT scans cannot.

Electroencephalogram (EEG), which records brain waves, may reveal abnormalities in the temporal lobe that are indicative of herpes simplex encephalitis.

When encephalitis is suspected, a sample of cerebrospinal fluid is taken using a lumbar puncture, which involves inserting a needle between two vertebrae in the patient's lower back. The sample is taken to count white blood cells and identify specific blood cell types, to measure proteins and blood sugar levels, and to determine spinal fluid pressure. Doctors use cerebrospinal fluid to test for herpes simplex encephalitis and to look for the presence of antibodies to the West Nile virus. While cerebrospinal fluid tests may help diagnose encephalitis, they cannot provide information on how severe the disease will be.

Blood tests are used to test for West Nile virus and other arbovirus infections.

If necessary, tiny samples of brain tissue are surgically removed for examination and testing for the presence of the virus. Tissue is prepared using staining techniques and then viewed under an electron microscope. In a few cases, the viruses in brain cells are able to be cultured; that is, the viruses can actually be made to replicate in samples. A brain biopsy is the gold standard for diagnosing rabies.

Treatment

With the exception of herpes simplex and varicella-zoster encephalitis, the viral forms of encephalitis are not treatable. The primary objective is to diagnose the patient as soon as possible so they receive the right medicines to treat the symptoms. It is very important to lower fever and ease the pressure caused by swelling of the brain.

Patients with very severe encephalitis are at risk for body-wide (systemic) complications including shock, low oxygen, low blood pressure, and low sodium levels. Any potentially life-threatening complication should be addressed immediately with the appropriate treatments.

Since it is difficult to determine the cause of encephalitis, and rapid treatment is essential, it is common to give the patient medication for the symptoms that respond to therapy without waiting to determine the cause of the illness.

Some experts advise immediately administering intravenous acyclovir, the standard treatment for herpes simplex encephalitis, to all patients whose symptoms indicate encephalitis.
Corticosteroids, which reduce inflammation, may also be administered immediately.
Antibiotics, which attack bacteria but not viruses, are used in case the cause of the symptoms is bacterial meningitis.

All encephalitis treatments are aimed at reducing symptoms.

Seizures may be prevented by using fosphenytoin (Cerebyx).
Seizures may be treated with intravenous lorazepam (Ativan).
Sedatives may be prescribed for irritability or restlessness.
Simple pain relievers may be used for fever and headache.
In patients who are otherwise stable, the only other treatment measures are to keep the head elevated and monitor the patient's status.

Intravenous acyclovir is the treatment of choice for encephalitis caused by herpes simplex virus (HSV) or varicella-zoster virus. Treatment must be initiated within 2 days of symptoms for the best outcome. In nearly all cases, the virus clears within 2 weeks of treatment. If it does not, medications are continued for another 2 weeks. In rare cases, surgical measures may be needed to relieve the buildup of pressure in the brain.

Acyclovir is usually administered in the hospital. However, some patients may be safely treated with intravenous medications at home after the first few days with close monitoring by a health professional. Valacyclovir and famciclovir may be used for the treatment of non-life-threatening HSV infection.

About 25% of patients who have been successfully treated for herpes encephalitis have a relapse. Early diagnosis and treatment may help reduce this risk. Doctors are investigating if a 3-month course of oral valacyclovir will improve remission rates after a patient completes treatment with intravenous acyclovir. Foscarnet (Foscavir), another powerful antiviral drug known as a pyrophosphate analogue, may be useful for herpes simplex viral strains that have become resistant to acyclovir.

No other drugs have been effective for treating arboviruses, including West Nile virus. A number of drugs used to treat other virus infections are being investigated. They include ribavirin (an antiviral drug used to treat influenza), interferon alfa 2a (Roferon-A) and other interferons, immunoglobulin G, and glycyrrhizin (a compound in licorice root with anti-viral activity). Researchers with the U.S. National Institutes of Health are investigating Omr-IgG-am, a blood-derived product that contains WNV antibodies, which can be given intravenously.

ADEM is usually treated with high-dose intravenous methylprednisolone, a powerful anti-inflammatory drug known as a corticosteroid. Intravenous immunoglobulin (IVIG), alone or in combination with methylprednisolone, is also showing promise in certain patients, including children with severe ADEM.

Vaccinations

Certain vaccinations can help prevent the diseases that can lead to encephalitis.

Measles used to be a very common childhood disease. In about 1 in 1,000 patients it can lead to encephalitis or death. The risk for these severe complications is highest in the very young and very old. Aggressive vaccination programs have reduced the incidence of measles in the U.S. to fewer than 100 cases a year. Rarely, patients who receive the live-measles vaccine develop encephalopathy (brain damage), but the risk is far lower than brain problems occuring from the disease itself.

Herpes zoster, or shingles, is a reactivation of the varicella virus, which causes chickenpox. Children (and adults who do not have a history of infection and who lack evidence of immunity) should receive 2 doses of the chickenpox vaccine. In 2006, a vaccine for shingles became available for adults age 60 years and older. [For more information, see In-Depth Report #82: Shingles and Chickenpox.]

Researchers are investigating a number of vaccines against the flavivirus family of arboviruses.

A vaccine (JE-VAX) is currently available for Japanese encephalitis. In travelers, it is only recommended for those visiting rural areas in high-risk Asian countries for more than 30 days. These countries include China, Korea, India and neighboring areas, and Southeast Asia. The disease may occur with lower frequency in Japan, Taiwan, Singapore, Hong Kong, and eastern Russia. A new type of Japanese encephalitis virus vaccine is currently in clinical trials.

Another type of vaccine (FSME-IMMUN) is used to prevent tick-borne encephalitis (TBE) in travelers visiting regions where this type of encephalitis is prevalent. TBE is found mainly in Eastern Europe, China, North Africa, and Russia. This vaccine is available in many European countries, but it is not yet approved in the United States.

Two types of vaccines, chimeric and DNA, are under investigation for West Nile virus, but it will be several years before these vaccines could become commercially available.

Anyone exposed to bats, or the secretions of an animal suspected of having rabies, should be evaluated for post-exposure rabies vaccine. Exposed individuals may also receive immune globulin unless they were previously vaccinated. Local health authorities are generally consulted. When the saliva of a potentially infected animal is exposed to an open wound or mucous membrane, treatment is generally warranted. However, the need to administer rabies immunization or immune globulin after saliva exposure to intact skin is not as clear. Veterinarians and animal handlers should be vaccinated. This does not eliminate the need for treatment if they are exposed to rabies, but it reduces the intensity of the treatment. Side effects of these shots include:

Pain
Redness
Headache
Stomach pain
Nausea
Dizziness
Muscle aches
Swelling at the injection site

Allergic response can occur after the first shot and as many as 21 days after a booster shot. Rare cases of neurological disorders have been reported that cause pain and paralysis in the legs and arms, which clear up in about 12 weeks.

Prevention

The risk for mosquito-born infections is highest between dusk and dawn, when mosquitoes feed. A good insect repellent is very helpful in reducing the risk for vector-borne disease. The most complete personal protection program for adults and most children is to apply the insect repellant DEET to the skin, and also permethrin to clothing and other surfaces.

Never use DEET products should on infants younger than 2 months. According to the Environmental Protection Agency (EPA), DEET products can safely be used on all children age 2 months and older. The EPA recommends that parents check insect repellant product labels for age restrictions. If there is no age restriction listed, the product is safe for any age. The American Academy of Pediatrics recommends that children use concentrations of 10% or less; 30% DEET is the maximum concentration that should be used for children. When deciding what concentration is most appropriate, parents should consider the amount of time that children will be spending outside, and the risk of mosquito bites and mosquito-borne disease.

When applying DEET, take the following precautions:

Do not use on the face, and apply only enough to cover exposed skin on other areas.
Do not over apply, and do not use under clothing.
Do not apply over any cuts, wounds, or irritated skin.
Only parents or an adult should apply repellent to a child. They should first put DEET on their own hands and then apply it to the child. They should avoid putting DEET not only near the child's eyes and mouth but also on the hands (since children frequently touch their faces).
Wash any treated skin after going back inside.
If using a spray, apply DEET outdoors -- never indoors. Spray repellents should not be applied directly on anyone's face.

Other Insect Repellent Products. In 2005, the U.S. Centers for Disease Control (CDC) added two new mosquito repellents to its list of recommended products: Picaridin and oil of lemon eucalyptus.

Picaridin, also known as KBR 3023 or Bayrepel, is an ingredient that has been used for many years in repellents sold in Europe, Latin America, and Asia. A product containing 7% picaridin is now available in the United States. Picaridin can safely be applied to young children and is also safe for women who are pregnant or breast-feeding. According to the CDC, insect repellents containing DEET or picaridin work better than other products.

In scientific tests, oil of lemon eucalyptus, also known as PMD, worked as well as low concentrations of DEET. However, oil of lemon eucalyptus is not recommended for children under the age of 3 years.

Permethrin is an insect repellent used as a spray for clothing and bed nets, which can repel insects for weeks when applied correctly. Electric vaporizing mats containing permethrin may be very helpful. A permethrin solution is also available for soaking items, but it should never be applied to the skin. Side effects from direct exposure may include mild burning, stinging, itching, and rash. In general, however, permethrin is very safe and its use may even reduce child mortality rates from malaria. People allergic to chrysanthemum flowers or who are allergic to head-lice scabicides should avoid using permethrin.

Eliminate Sources of Standing Water. Currently, the only proven method for reducing mosquito populations is to eliminate sources of standing water.

Look for any source of standing water, where mosquitoes can breed. For example, discard any rubbish with standing water, such as old tires, cans, and bottles. (Even bottle caps can breed mosquitoes.) Turn over wading pools and wheelbarrows when not in use. Change bird bath water every 3 - 4 days. A product called Mosquito Dunk can be used to prevent breeding in standing water.
Swimming pools and hot tubs should be clean and chlorinated or drained and covered if not in use.
Clean vegetation and debris from the edges of ponds.
Keep gutters clean and unclogged.

Mosquito Traps. Mosquito traps use various methods for repelling or attracting and trapping the insects. Effective traps are expensive, and they usually require electricity or propane, which adds to the cost. Use mosquito trap machines only outdoors. While many traps can draw in significant numbers of mosquitoes, they have limitations. Do not rely on them for sole protection.

All baits should aim to attract the female mosquito, which is the primary transmitter of the viruses. However, different baits may be more or less effective. Some may even attract one species and not others. For example, a comparative study of three traps that used similar attractants found that after 20 hours, the Magnet Liberty and Mosquito Trap MK01 attracted 75% of mosquitoes in a single area, while the Sonic Web had attracted only 25%. However, all three traps tended to attract twice as many Aedes mosquitoes (which carry La Cross and Eastern Equine encephalitis) as the Culex (which transmits West Nile and St. Louis Encephalitis).

Bug Zappers. Insect light traps (commonly called bug zappers), which attract and electrocute insects, may actually spread viruses and bacteria that are on the insects. They are also not very effective for killing female mosquitoes.

Encouraging Natural Defenders. Some attempts have been made to control mosquito populations with natural defenders, including building bat and bird houses to attract natural predators or growing certain insect-repellent plants.

Citronella Candles. Burning citronella candles reduces the likelihood of bites. (Indeed, burning any candle helps to some extent, perhaps because the generation of carbon dioxide diverts mosquitoes toward the flame.)

Your home environment, personal hygiene, and what you wear can also help reduce your risk for mosquito bites:

Wear trousers and long-sleeved shirts, particularly at dusk. One survey suggested that this measure may significantly reduce the incidence of mosquito-born disease.
Sleep only in screened areas.
Air-conditioning may reduce mosquito infiltration. Where air-conditioning is not available, fans may be helpful. Mosquitoes appear to be reluctant to fly in windy air.
Don't wear perfumes.
Cover up bare skin after dusk.
Wash your hair at least twice a week.

Public health measures are the best methods for controlling mosquitoes.

Spraying. Local areas that experience outbreaks of encephalitis from mosquitoes usually have a spraying program.

Insecticides containing synthetic pyrethroids (permethrin, resmethrin, and sumithrin) are generally recommended by consumer groups as being the most effective and the least toxic to people (although they are toxic to fish and bees).
Malathion and naral -- another pesticide -- are organophosphates and approved for spraying mosquitoes. Malathion specifically has been widely used in a number of areas. Organophosphates, however, can have toxic effects on the nervous system. Some people, for example, have reported being sick after exposure to Malathion. In addition, there is a risk that mosquitoes will develop resistance to it.

Report Dead Birds. Dead birds may be indicators that the West Nile virus has reached a specific region. Report any dead birds to your local public health authorities. You should never touch a dead bird with your bare hands.

Resources

www.cdc.gov -- The U.S. Centers for Disease Control (CDC)
www.cdc.gov/ncidod/dvbid/arbor -- CDC website for arboviruses
www.cdc.gov/ncidod/dvbid/westnile -- CDC West Nile virus website
www.ninds.nih.gov -- National Institute of Neurological Disorders and Stroke
www3.niaid.nih.gov -- National Institute of Allergy and Infectious Diseases
www.mosquito.org -- American Mosquito Control Association
www.npic.orst.edu/wnv -- National Pesticide Information Center's West Nile virus resource guide

References

Bleck TP. In: Goldman L and Ausiello DA, eds. Cecil Medicine. 23rd edition. Saunders; 2007.

Modlin JF. In: Goldman L and Ausiello DA, eds. Cecil Medicine. 23rd edition. Saunders; 2007.

Nath A, Berger JR. In: Goldman L and Ausiello DA, eds. Cecil Medicine. 23rd edition. Saunders; 2007.

Whitley RJ. In: Goldman L and Ausiello DA, eds. Cecil Medicine. 23rd edition. Saunders; 2007.

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