As if the itchy eyes, sneezing, runny nose, and sinus congestion from pollen allergies weren't enough, if you're one of the lucky 33 percent who also suffers from oral allergy syndrome (OAS), you may also have to deal with uncomfortable itchiness, tingling, or swelling in the mouth, lips, or throat when eating certain fresh fruits, vegetables, or nuts.
Because proteins in allergy-inducing pollens are so similar to the proteins in certain types of foods, it confuses the body into thinking those food proteins are an allergen. As soon as the person eats the offending food, it triggers their sensitive immune system to release chemicals that cause cells in the mouth and throat to swell. These reactions, called cross reactions, are usually mild and last for 10 to 30 minutes, but in rare cases people can experience anaphylaxis, a life-threatening reaction that causes blocked airways, low blood pressure, vomiting, and diarrhea.
Only fresh fruits, veggies, and nuts can cause OAS reactions. Eating canned, cooked, dried, or frozen versions of those same foods usually cause no reaction since the proteins change during those processes. Also, just so you know, OAS is different than a nut allergy. In order for a person to have OAS, they must have an allergy to pollen. Check out the chart below to see which foods may be associated with certain seasonal allergies.
Note: Cross reactions may occur with some or all of the foods listed in the right-hand column.
|Type of Allergy||Foods That May Cause Cross Reactions|
|Birch Tree pollen||Almonds, apples, apricots, carrots, celery, cherries, coriander, fennel, hazelnuts, kiwi, lychee fruit, nectarines, parsley, parsnips, peaches, pears, peppers, persimmon, plums, potatoes, prunes, soy, wheat, zucchini, walnuts|
|Grass pollen||Celery, watermelon, oranges, peaches, tomatoes|
|Ragweed pollen||Bananas, melons (watermelon, cantaloupe, honeydew), gourd family (cucumber, zucchini and squash), chamomile, echinacea, sunflower seeds, zucchini|
|Alder pollen||Celery, pears, apples, almonds, cherries, hazelnuts, peaches, parsley|
|Mugwort pollen||Celery, fennel, carrots, parsley, coriander, sunflower, peppers|
Just because you have an allergy to one of the pollens listed above, does not mean you'll automatically have a reaction to the foods listed to the right. If you've been noticing swelling, itching, or tingling in your mouth or throat, it's best to get tested by an allergist.