Spring is here, and so is the pollen! Did your doctor tell you that you are allergic to trees, grass, or weeds pollen? You're used to the usual symptoms; breathing problems, sneezing attacks, and teary, itchy eyes. But then you notice that some fresh fruits, vegetables, and tree nuts are starting to cause an itchy mouth, scratchy throat, itchy ears, and swelling of the lips, mouth, tongue, and throat— even when there is no pollen around? You may have something called oral allergy syndrome.
Also called a pollen-food syndrome, oral allergy syndrome is caused by cross-reactivity of allergens found in pollen and raw fruits, vegetables, and some tree nuts. The immune system recognizes the pollen and similar proteins in the food and causes an allergic response. People affected by oral allergy syndrome can usually eat the same fruits or vegetables in cooked form because the proteins are altered during the heating process until the immune system no longer recognizes the food.
According to the ACAAI (American College of Allergy, Asthma, and Immunology), known cross-reacting fruits, vegetables, and pollens are the following:
| Birch pollen | Ragweed Pollen | Grasses | Mugwort Pollen |
| Almonds (raw) | Bananas | Celery | Apples |
| Apples | Cantaloupe | Cantalope | Bell Peppers |
| Apricots | Cucumber | Honeydew | Carrots |
| Carrots | Honeydew | Oranges | Celery |
| Celery | Sunflower Seeds | Peaches | Garlic |
| Cherries | Watermelon | Peanuts | Onion |
| Hazelnuts | Zucchini | Tomatoes | Some spices (caraway, |
| Kiwis | Watermelon | parsley, coriander, anise, | |
| Peaches | and fennel | ||
| Pears | |||
| Plums | |||
| Potatoes (raw) |
If you are experiencing a reaction beyond the mouth area, it could be a true allergy to specific food and you may have a potentially severe reaction. It is recommended that you consult with your doctor and conduct an allergy test to confirm the diagnosis.