If fruits or vegetables sometimes cause your mouth to itch or swell, you may have a condition known as pollen-food allergy syndrome (also known as oral allergy syndrome or OAS). And if you have this condition, you may also suffer from seasonal hay fever.
Why the link? Chalk it up to a phenomenon known as “cross-reactivity.” If you were to compare the chemical make-up of certain allergy-causing pollens to proteins found in various fruits and vegetables, you would find that they are nearly identical. Thus, if your body typically reacts to a bit of birch pollen in the air, when it detects a similar protein in that apple you just ate, it will likely have an allergic reaction.
If seasonal allergies are cutting into your quality of life, consider seeing an allergist for testing and treatment. If you find that you are allergic to any of the pollens below, be aware that eating the fruits and vegetables that they resemble in chemical composition may lead to allergic reactions in your mouth and throat.
Birch pollen: Apple, almond, carrot, celery, kiwi, hazelnut, peach, pear, plum
Ragweed pollen: Banana, cucumber, melon (cantaloupe, honeydew, watermelon), zucchini
Grass pollens: Melon, orange, peach, tomato
About 70 percent of people with pollen allergies also suffer from pollen-food allergy syndrome. It is not as common in young children but tends to develop in late childhood, adolescence, or adulthood. So if you suddenly find yourself feeling an element of discomfort while eating the same fruits and veggies you used to enjoy without symptoms, consult an allergist about desensitization therapy (either through allergy shots, under-the-tongue drops, or sublingual tablets).