Do you suffer from seasonal allergies? Does your mouth or throat itch or burn when you eat certain raw fruits and vegetables? You may be suffering from oral allergy syndrome (OAS).
According to the American Academy of Allergy, Asthma, and Immunology (AAAAI), OAS is a form of allergic reaction that occurs upon contact of the mouth and throat with raw fruits or vegetables. The reaction occurs because the proteins found in some fruits and vegetables are similar to those found in pollen, which can confuse the immune system and cause an allergic reaction or make existing symptoms worse.
The most common symptoms of OAS include rapid onset of itching or swelling of the lips, mouth or throat and may include irritation of the gums, eyes or nose. Symptoms normally appear within minutes of eating the offending food and are often worse during the spring and fall pollen seasons.
National Jewish Health provides this informative video describing OAS:
According to a peer-reviewed article entitled “Oral Allergy Syndrome” appearing in the Canadian Medical Association Journal, the easiest and safest way to treat oral allergy syndrome is to avoid the foods that cause the problem.
They provide the following list of environmental allergens and the corresponding foods that may prove problematic due to cross-reactivity:
| Pollen | Fruit | Vegetables/Spices | Nuts/Seeds/ Legumes |
|---|---|---|---|
| Alder | Apples, cherries, peaches, pears | Parsley, celery | Almonds, hazelnuts |
| Birch | Kiwi, apples, pears, plums, peaches, nectarines, apricots, cherries, tomatoes | Celery, carrots, potatoes, parsnips, green peppers, dill, cumin, peas, cilantro, fennel | Hazelnuts, walnuts, almonds, peanuts, lentils, beans |
| Grass | Melon, watermelon, oranges, tomatoes | Potatoes | Peanuts |
| Mugwort* | Celery, carrots, dill, parsley, fennel, coriander, cumin | Sunflower seeds | |
| Ragweed | Watermelon, cantaloupe, honeydew, bananas | Zucchini, cucumbers, squash | |
| *Also associated with honey. | |||
Though OAS is generally benign requiring little beyond avoidance, the American College of Allergy, Asthma, and Immunology (ACAAI) issues the following warning:
If you or your child experience a reaction beyond the mouth area after eating a fresh fruit or raw vegetable, that food could be considered a risk for anaphylaxis, a serious reaction that is rapid in onset and may cause death. In one study, researchers found that oral allergy syndrome symptoms progressed to systemic symptoms in nearly 9 percent of patients and to anaphylactic shock in 1.7 percent of patients. Consult with your allergist for more information and to determine whether you should carry an epinephrine auto-injector to treat such potential severe reactions.
- ORAL ALLERGY SYNDROME (OAS) OR POLLEN FRUIT SYNDROME (PFS) — AAAAI
- Oral Allergy Syndrome (OAS) — National Jewish Health
- Oral Allergy Syndrome (OAS) — Children’s Hospital of Philadelphia
- Oral Allergy Syndrome — Canadian Medical Association Journal
- Oral Allergy Syndrome — ACAAI
