Japanese Guideline for Food Allergy 2014.

A food allergy is defined as "a phenomenon in which adverse reactions are caused through antigen-specific immunological mechanisms after exposure to given food." Various symptoms of food allergy occur in many organs. Food allergies are classified roughly into 4 clinical types: (1) neonatal and infantile gastrointestinal allergy, (2) infantile atopic dermatitis associated with food allergy, (3) immediate-type food allergy (urticaria, anaphylaxis, etc.), and (4) food dependent exercise-induced anaphylaxis and oral allergy syndrome (i.e., specific forms of immediate food allergy). The therapy for food allergies includes treatment of and prophylactic measures against hypersensitivity such as anaphylaxis. A fundamental prophylactic measure is the elimination diet. However, elimination diets should be used only if necessary because of the patient-related burden. For this purpose, it is very important that causative foods be accurately identified. There are a number of means available to identify causative foods, including the history taking, a skin prick test, detection of antigen-specific IgE antibodies in the blood, the basophil histamine release test, the elimination diet test, and the oral challenge test, etc. Of these, the oral challenge test is the most reliable. However, it should be conducted under the supervision of experienced physicians because it may cause adverse reactions, such as anaphylaxis.