Food allergy.

Food allergy is an immunologically mediated hypersensitivity reaction that occurs in 1% to 2% of the general population and in about 8% of children. Reactions mediated by IgE antibodies are the most common type of food allergy and can cause asthma, rhinitis, atopic dermatitis, urticaria, and anaphylaxis, which can be lethal. A proper diagnosis can be established through a careful history and physical examination, tests for IgE antibodies specific for food antigens, a favorable response to an allergen elimination diet, and, if necessary, blinded and controlled allergen challenge. The only effective therapy is avoidance of the problem foods. Resolution of the sensitivity over time is more common in younger patients than in adults and for some foods more than others. Most adverse food reactions are due to nonimmunologic intolerance and can be managed differently.