Food Allergy

Food allergy, in contrast to other adverse reactions attributable to foods, is characterized by an adverse specific immune response occurring reproducibly on exposure to a given food. Food allergies may be immunoglobulin E (IgE)-mediated, cell-mediated, or “mixed” adverse immune responses. IgE-mediated reactions are typically sudden in onset following exposure to a food allergen, whereas cell-mediated responses may result in chronic inflammation or delayed symptoms. Acute IgE-mediated reactions can have cutaneous, ocular, gastrointestinal, respiratory, and/or cardiovascular symptoms. Cell-mediated food-allergic reactions include a number of disorders affecting the gastrointestinal tract including food-protein-induced enterocolitis syndrome (FPIES), food-protein-induced enteropathy, and food-protein-induced proctocolitis. Mixed IgE and cellular responses are responsible for food-related eosinophilic esophagitis and gastroenteritis. Diagnostic evaluation of food allergy includes the history and physical examination, tests for food-specific IgE antibodies, elimination diets, and physician-supervised oral food challenges. Primary management remains allergen avoidance. Prompt administration of epinephrine is the recommended treatment in the event of an accidental exposure resulting in an allergic reaction. Immunotherapy is an emerging management approach to patients with IgE-mediated food allergy. Different routes of administration are being studied and developed, including oral (OIT), sublingual (SLIT), subcutaneous (SCIT), and epicutaneous (EPIT, or a skin patch) immunotherapy. Other treatment approaches under investigation include administration of biologic agents as well as vaccines to specific food allergens.