DR. J. OHAYON - ALLERGY & IMMUNOLOGY CLINIC

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What is Oral Allergy Syndrome (OAS)?

OAS (also known as pollen food syndrome) is a form of contact allergy that occurs with contact of the mouth and throat with raw fruits or vegetables.


OAS is generally considered to be a mild form of food allergy.

Cause and Triggers of OAS

Oral allergy syndrome is caused by cross-reacting allergens found in both pollen and raw fruits, vegetables, and some tree nuts. The immune system recognizes the pollen and similar proteins in the food and produces an allergic response.


Although not everyone with a pollen allergy experiences oral allergy syndrome when eating the following foods, there are common associations between the following allergens:


Symptoms of OAS

Symptoms of OAS include itchiness or swelling of the mouth, face, lip, tongue and throat.

Symptoms usually appear immediately after eating raw fruits or vegetables, although in rare cases, the reaction can occur more than an hour later.

The symptoms are usually localized to the mouth and rarely progress to other systems.

Recommendations

1. HEAT the cross-reactive foods prior to consumption

2. PEEL foods prior to consumption

3. WEAR GLOVES when peeling fruits to reduce the symptoms of hives

4. MANAGING seasonal allergy symptoms with the recommended treatment is key to coping with oral allergy syndrome


Are fruits and vegetables making your mouth itchy?



Cross-Reactive Foods

Pollen/Allergen

Season

Fruits

Vegetables

Nuts

Spices

Others

Trees

Spring

Apple, apricot, cherry, fig, kiwi, nectarine, pear, plum, peach

Carrots, celery, parsley

Almonds, hazelnuts, peanuts

Chicory, coriander, fennel

Soybean

Grass

Summer

Celery, melons, oranges, peaches, tomato

White potato




Ragweed

Late Summer/Fall

Banana, melons

Cucumber, zucchini



Sunflower seeds

Mugwort

Fall


Bell pepper, broccoli, cabbage, cauliflower, chard, garlic, onion, parsley


Aniseed, caraway, coriander, fennel, black pepper