Skin manifestations of food allergy.

The pediatrician is faced with evaluating a panoply of skin rashes, a subset of which may be induced by food allergy. Acute urticaria is a common manifestation of an allergic skin response to food, but food is rarely a cause of chronic urticaria. Approximately one third of infants/children with moderate to severe atopic dermatitis have food allergy. Although diagnosis of acute urticaria provoked by a food may be evident from a straightforward history and confirmed by diagnostic tests to detect food-specific IgE antibody, determination of the role of food allergy in patients with atopic dermatitis is more difficult and may require additional diagnostic maneuvers, including elimination diets and oral food challenges. The immunopathologic basis of food-allergic disorders that affect the skin and a rational approach to diagnosis and treatment are discussed. Additional disorders that are caused by or mimic ones caused by food allergy are reviewed.