Food allergy is principally a problem in infancy and early childhood. Food allergy/intolerance may cause a broad spectrum of symptoms and signs in children, including generalized reactions, such as anaphylactic shock. Reactions are localized mainly in the gastrointestinal tract, but food allergy/intolerance may also cause local symptoms in other organs such as the skin and the respiratory tract. About 50-70% demonstrate cutaneous symptoms, 50-60% gastrointestinal symptoms, and 20-30% respiratory symptoms. Among young children with food allergy/intolerance the majority have two or more symptoms with symptoms occurring in two or more organ systems. The symptoms occur primarily within a few minutes after food exposure (immediate reactions), however delayed reactions in the skin, gastrointestinal tract and lungs may also occur. Among children with symptoms suggestive of food allergy/intolerance, the diagnosis can be confirmed by controlled elimination/challenge procedures only in about one third of the patients. A proper diagnosis is important in order to avoid unnecessary restrictive diets and risk of malnutrition. (C) 1997 Elsevier Science B.V.