What is Oral Allergy Syndrome?
Oral allergy syndrome (OAS) is caused by cross-reactivity between proteins in fresh fruits and vegetables and pollens. This syndrome occurs in a large number (up to 70 percent) of people with pollen allergy. The proteins in the fruits and vegetables causing OAS are easily broken down with cooking or processing. Therefore, the OAS typically does not occur with cooked or baked fruits and vegetables, or processed fruits such as in applesauce.
Most people with OAS have symptoms such as itching, burning, tingling and occasion swelling of the lips, mouth, tongue and throat where the fresh fruit or vegetable touched. Symptoms usually only last a matter of seconds to a few minutes, and rarely progress to anything more serious. The following fruit-pollen associations have been shown in people with OAS. The following list is just some of the foods that can cause OAS, it is not meant to be all inclusive.
- Ragweed (weed): melons (watermelon, cantaloupe, honeydew), bananas, cucumbers and zucchini.
- Birch (tree): potatoes, carrots, cherries, celery, apples, pears, plums, peaches, parsnip, kiwi, hazelnuts, almonds and apricots.
- Mugwort (weed): celery, carrots, various spices.
- Grasses: tomatoes, potatoes, peaches.
OAS is diagnosed when there is a history of the above symptoms in people with seasonal allergic rhinitis with pollens as a trigger and when they eat these respective foods have the common reaction.
If you have or suspect OAS, contact your local allergist or allergy doctor. He/She can help diagnose it with testing and help minimize future reactions with different tips and/or treatment options.