The term food allergy is usually used to describe an immune-mediated disease which is IgE-mediated and results in type I acute allergic reactions (according to the definition of Gell and Coombs), mostly within half an hour up to 2 h after ingestion. Sometimes, the term food allergy is also used for non-IgE-mediated disease, e.g., celiac disease, in which IgA antibodies play a role. However, its symptoms diverge considerably from type I IgE-mediated food allergy, and the underlying pathophysiological mechanism is completely different. This entry will therefore focus on IgE-mediated food allergy.

IgE-mediated food allergy is characterized by the development of acute symptoms, usually within minutes but sometimes after an interval of 1–2 h after eating the culprit food. Often symptoms start with itching in the mouth and (a feeling of) swelling which might extend to the ears and the throat. Usually, these so-called oral allergy symptoms are mild, but in rare...