Many patients with pollen allergies will experience itching of the mouth, lips, tongue and throat when eating fresh fruits, vegetables and nuts. This can be very uncomfortable but usually does not spread to other parts of the body or cause serious allergic reactions. Cooking or steaming the fruit or vegetable often significantly lessens these reactions.
Pollen-food syndrome (also called oral allergy syndrome) is thought to be due to similarities between proteins found in certain pollens and certain foods. These food reactions may vary during the year depending on outdoor pollen levels. Some patients will react to numerous foods, others to only one.
People allergic to tree pollens may develop symptoms after eating various foods, including almonds, apples, apricots, avocados, bananas, carrots, cherries, kiwi fruit, peaches, pears, plums and wheat. People allergic to ragweed often have problems with bananas, cantaloupes, cucumbers, green peppers, sunflower seeds, honeydew melons, watermelons, zucchini and hibiscus or chamomile tea. People allergic grass pollen may have problems with melons, tomatoes and oranges.
Diagnosis can be made by careful observation of symptoms beginning seconds to minutes after eating fresh fruits, vegetables or nuts. Allergy skin testing can also be helpful, particularly if the patient is tested with fresh foods.
The main treatment for any type of food allergy or food sensitivity is avoiding eating that food. Peeling, cooking or steaming foods has been shown to reduce reactions to some foods (fruits and vegetables, but not nuts). Antihistamines such as Benadryl, Claritin, Allegra and Zyrtec can reduce the reaction. Some patients treated with allergen immunotherapy (allergy shots) for their pollen allergy may notice a reduction in their reaction to foods. However, allergy shots for foods are not effective or safe.
In very rare cases, pollen-food allergy can progress to more serious, systemic anaphylactic reactions to the fruit, vegetable or nut, which is why it is always best to avoid foods that cause reactions. Patients with a history of serious reactions to foods should carry an EpiPen (auto injectable epinephrine) with them at all times.