Oral allergy syndrome (also called pollen-food syndrome) may affect patients who are allergic to inhaled plant pollens (e.g. hay fever or seasonal allergies). The patient’s immune system reacts to a specific protein in the plant pollen. If certain fruits or vegetables contain a similar protein, the patient may experience tingling in the mouth when eating the raw fruit or vegetable (plant proteins usually break down with heat). Reacting to more than one substance because they contain similar proteins is called cross reactivity. There are many lists that indicate what fruit or vegetables cross react with each plant pollen, but these lists are variable and there is likely geographical variation. Future research may show that cross reactivity goes far beyond the current understanding of oral allergy syndrome.
Posted in: Summer2015-Q&A