Condition Center: Allergies

This informational guide, part of POPSUGAR's Condition Center, lays out the realities of this health concern: what it is, what it can look like, and strategies that medical experts say are proven to help. You should always consult your doctor regarding matters pertaining to your health and before starting any course of medical treatment.

Allergies are incredibly common. They're the sixth leading cause of chronic illness in the US and affect more than 50 million people every year, reports the Asthma and Allergy Foundation of America (AAFA). While some allergies are easy to manage, others cause severe symptoms. Food allergies alone are responsible for roughly 30,000 emergency department visits and around 200 deaths every year, according to the Center for Disease Control and Prevention (CDC).

Understanding Allergies

Allergies are the result of the body's immune system reacting to a substance, says Neha Sanan, DO, allergist and immunologist. The body identifies the substance as harmful and releases immune chemicals like histamine, which leads to allergy symptoms, says Shawn Nasseri, MD, Mayo Clinic trained ENT and allergy expert.

Allergies can be experienced by anyone and can develop at any time in life. They might be seasonal (as with pollen allergies) or perennial (occurring year-round). But the symptoms a person experiences depends on the type of allergen they're exposed to, and can range from itchiness, hives, sneezing, or diarrhea to severe swelling of the mouth, nose, and throat.

The most severe type of reaction is known as anaphylaxis, which is potentially fatal. It happens when an allergic reaction causes the body goes into shock, leading to a drop in blood pressure and a narrowing of the airways, according to Mayo Clinic. It can occur within seconds, which is why people with severe allergies often carry epinephrine autoinjectors (commonly referred to as an EpiPens); EpiPens inject the body with epinephrine, which keeps the airways open for long enough for the person to get to the emergency room.

Causes of Allergies

Allergies are essentially an immune reaction to a foreign substance or allergen; when you're exposed, you have a reaction. Common allergens, according to the Mayo Clinic, include:

• Airborne allergies such as dust, pollen, mold, and animal fur or dander.
• Certain foods, including peanuts, soy, shellfish, and eggs.
• Insect stings. "Bees, wasps, hornets, yellow-jackets and fire ants are the most common stinging insects that cause an allergic reaction," according to the Asthma and Allergy Foundation of America.
• Certain medications. Penicillin, antibiotics that contain sulfonamides (sulfa drugs), anticonvulsants (often used to prevent epileptic fits), and certain nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspiring or ibuprofen, are all common triggers of drug allergies, according to the American College of Allergy, Asthma, and Immunology.

Generally, there are factors that can make a person more likely to develop allergies in their lifetime.

• A family history of asthma or allergies. Allergies are often hereditary, according to the American College of Allergy, Asthma, and Immunology.
• Age. Infants and young kids are more likely to develop certain food allergies, but they often grow out of them as they age, the Mayo Clinic notes.
• Having another allergic condition. If you're already allergic to one food or have hay fever, you may be at increased risk of becoming allergic to another food, reports the Mayo Clinic.
• Climate change. Studies show that climate change may be causing seasonal allergy season to last longer and affect more people than ever before.
• Pollution. There's evidence that kids who are exposed to more pollution are more likely to develop allergic disease.

Most Effective Treatments For Allergies

If you think you have allergies, visit an allergist to determine what you're allergic to. Unchecked allergies can lead to inflammation and infection, says Dr. Nasseri: "Things like ear infections and sinus infections can start to occur more frequently, leading to asthma or structural sinus issues."

When it comes to allergic reactions, preventive measures are key, Dr. Sanan says. Once you know what you're allergic to, you can make a plan for avoiding known triggers and dealing with any future exposures (such as by carrying an EpiPen or antihistamines just in case).

It may also be helpful to keep overall inflammation down, since allergic reactions can trigger inflammation, Dr. Nasseri says. He suggests eating an anti-inflammatory diet, filled with green vegetables, nuts, fish, and olive oil. That said, diet tweaks like this alone likely can't treat many allergies, like pollen allergies.

You can also ask your doctor about immunotherapy. This preventive treatment involves having a doctor give you increasing doses of an allergen (starting with a very small dose) in order to make your immune system less reactive to it, according to ACAAI. It can take time, and it must be done under the supervision of a healthcare professional. But for people with severe allergies, immunotherapy can be life-changing.