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Oral Allergy Syndrome

May 9, 2024 | The Healthy Way Newsletter

What is Oral Allergy Syndrome?

Pollen food allergy syndrome (PFAS), or oral allergy syndrome (OAS), is categorized as a form of food allergy resulting from cross-reactivity between proteins found in fresh fruits, vegetables, and nuts with pollens. This condition affects a significant portion of the population, up to 70%, of individuals with pollen allergies. The proteins triggering OAS symptoms can be broken down through cooking or processing, making cooked or baked fruits and vegetables generally safe for consumption, with exceptions like celery and nuts that may still cause reactions even after being cooked.


Symptoms of PFAS/OAS typically include itching, burning, tingling, and occasional swelling of the lips, mouth, tongue, and throat upon contact with fresh fruit or vegetables. Tightness in the throat may also be experienced. While symptoms usually subside within seconds to minutes and rarely escalate, studies suggest that around 9% of OAS cases may exhibit more severe allergic reactions, with up to 2% experiencing anaphylaxis. Symptoms tend to be more prevalent and severe during the pollen season associated with the specific allergen.

OAS, PFAS, pollen allergy, food allergy, cross-reactivity


Diagnosing OAS can often be done by your healthcare provider through a series of questions. If there is uncertainty about pollen allergies, you may be referred to an allergy specialist for further assessment. The specialist may suggest skin testing for specific pollens or foods triggering symptoms. Alternatively, they may conduct a food challenge where you consume the suspected food while under observation.

It is crucial that skin testing and food challenges are performed by an allergy specialist to ensure safety and accurate interpretation. In some cases, testing with fresh fruits and raw vegetables may be necessary as commercial food extracts may not always provide reliable results.

Foods and Pollens Connection

Certain pollens are linked to OAS reactions to particular foods, such as ragweed triggering responses to banana, watermelon, cantaloupe, honeydew, zucchini, and cucumber. However, not all individuals allergic to a specific pollen will react to all or any of these foods, and reactions may vary over time.

Here is a short list of pollens and cross-reacting foods you can refer to if you are not sure whether a product will cause an allergic reaction:

Treatment involves avoiding fresh fruits or vegetables that trigger symptoms. Antihistamines can help, but using them can be dangerous to your health in general and your brain in particular.

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About Me

I'm Dr. Elena Krasnov, N.D and I've been healing people for decades with my holistic and comprehensive approach to health.

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