Pollen Food Syndrome

If you suffer from spring time hay fever, then its very likely you are birch pollen allergic. In some older children and adults, you may experience predominatly mild symptoms (itchy mouth/throat, itchy tongue, mild lip swelling, lump in the throat) after eating fresh food such as apples, cherries, carrots or stone fruits. However, if they are cooked or heated you have no symptoms and can tolerate it. The proteins in these foods are very similar to birch pollen and therefore these foods bind to your allergic (IgE) birch antibodies and this results in a mild allergic reaction. However, heating the food means the proteins in the fruits change shape and then your birch antibodies can't bind them and so you don't react. Similarly, when you digest them the protein gets broken down, which is why one generally only experiences mild reactions.

Also be aware that some nuts such as almond, hazelnut, peanut, walnut and pecan can also cause pollen food syndrome, however it is important to differentiate that from a primary nut allergy, so you may wish to seek medical advice.

See the following information leaflet for more information. https://www.bsaci.org/wp-content/uploads/2024/03/Pollen-Food-Syndrome-PIL.pdf