The interpretation of epidemiological data on food hypersensitivities should clearly separate two issues: the disposition to respond symptomatically to certain foods and the actual reactions occurring, which can be observed only when there is sufficient consumption or targeted exposure/provocation.The exact specification of the case definition is essential for reporting and interpreting food hypersensitivity frequencies. In Europe, prevalence estimates of self-reported reactions are reported from 5.7 to 61.6 %, and physician-diagnosed hypersensitivities from 0.2 to 4.2 %. Consideration of only double-blind proven immediate-type reactions gave estimates ranging from 0.0 to 2.2 %. The disposition for severe reactions against food might be less frequent, but cannot be estimated robustly from published data. The only data available for Germany estimates a prevalence of IgE-mediated reactions of 2,5% for Berlin.The most common triggers of early childhood food allergy are cow's milk and hen's egg, which usually cause mild symptoms, limited to the skin. Food allergy aquired in infancy usually disappears by early school age.The European Anaphylaxis Registry documents the spectrum of severe allergic reactions. England has a larger case series for fatal reactions. No incidence can be estimated from either approach, because reporting is voluntary. Additionally, the discussed data does not inform about the clinical relevance of severe allergic reactions against foods.Future systematic studies about the incidence and course of food hypersensitivity should examine sufficiently large groups of people using objective diagnostic criteria.
Keywords: Anaphylaxis; Food allergy; Food hypersensitivity; Oral food challenge; Prevalence.