[Diagnosis of food allergy]

The diagnosis of food allergy is one of the most difficult tasks in allergology, as only some of the hypersensitive reactions are of allergic origin, and even those that are allergic are not always IgE mediated. On the basis of the history, an attempt is made to determine the type of symptoms and the degree of severity, and identify eliciting foodstuffs. As diagnostic aids, prick tests and allergen-specific IgE tests have their limitations, since only IgE-mediated allergies can be identified. Diagnosis is based upon dietary elimination and subsequent challenge. Challenge must be repeated several times and a placebo controlled double blind approach be adopted. No foodstuff should be eliminated from the diet solely on the basis of prick test results.