When we develop allergic (IGE) antibodies to certain pollens - ragweed, some grasses and minor weeds and birch tree pollen - those antibodies make the immune cells in the oral cavity (mouth, tongue, the back of the throat) react to certain fresh or raw fruits and/or vegetables. Families of proteins are shared between those fruits and vegetables and the pollens and so the immune response is triggered or stimulated. The most common foods involved are apples, stone fruits, melons, carrots and celery, cucumber, bananas, kiwi, avocado. At times, peanuts and tree nuts can trigger such symptoms. When those foods are processed or cooked the proteins change their form so the immune system is not activated as it does not recognize the food as a trigger any longer.
The good news about this syndrome is that it is fairly benign and there is less than 0.5% of systemic or anaphylactic reactions so we usually do not prescribe an epinephrine in such cases. You can safely continue to consume the offending foods in their "cooked/processed" forms, just avoid eating them raw/fresh. Some patients who do allergen immunotherapy or allergy shots for their inhalant allergies notice less or even no reactions to the foods over time, but not everyone experiences an improvement to a degree to allow them to freely eat the foods. So, not much to worry about.
Thank you for the question and hope this helps you in some way.
Monika Korff, MD
Duane Wong MD
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