Food allergy.

Food allergy is defined by a specific sensitization against food allergens which is associated with a clinical reaction. Immediate reactions are most common and the skin is most often involved in food allergy. Most food allergies are IgE-mediated although eczema reactions in atopic dermatitis and in hematogenous contact dermatitis to foods can be mediated by specific T-lymphocytes. Only few foods are responsible for the majority of most reactions in childhood. In adults up to 60% of all food allergic reactions are due to cross reactions between foods and inhalative allergens. A stepwise procedure which takes individual factors into account is necessary in the diagnostics of food allergy. The diagnostic algorithm in food allergy is not significantly different from that of other allergies. The oral provocation is the only method to prove food allergy in patients without a convincing history. A specific elimination diet is the only intervention which has been proven to be effective. Further therapeutic approaches are still under study and include specific immunotherapy, specific oral tolerance induction and treatment with anti-IgE antibodies.