Diagnosis and management of food hypersensitivity

Physicians and other healthcare professionals are regularly confronted by patients with numerous signs and symptoms related to the upper and lower respiratory tract, skin, and gastrointestinal tract. After frustration with multiple medication courses or with the patient's or parent's initiative, the question may arise as to whether food allergies are contributing to the problems. Confusion over what constitutes food allergy exists in the medical community as well as in the public. This article clarifies terminology and discusses common presentations, diagnosis, and practical management of food allergy. The term food allergy is often used loosely and incorrectly by physicians, the public, and the media. An accurate general. term to describe any abnormal reaction to a food or food additive is adverse food reaction.(14) Adverse food reactions can be the result of food intolerance or food hypersensitivity.(2) Food intolerance accounts for a majority of adverse food reactions and is not immune-mediated. Examples include toxic food poisoning (vomiting and diarrhea from ingestion of staphylococcal or salmonella toxins), pharmacologic effects (jitteriness from caffeine in a cola beverage), and metabolic disorders (bloating and flatus from lactase deficiency). The terms food allergy or food hypersensitivity should be reserved to define an immunologically mediated adverse food reaction. The classic food hypersensitivity reaction is mediated via food-specific IgE-antibodies and, in the most dramatic case, can lead to food-induced anaphylaxis. The other group of food hypersensitivity reactions are non-IgE mediated but involve other immunologic reactions and primarily manifest gastro-intestinally. Examples include food-induced enteropathies, such as celiac disease with its characteristic elevated IgA anti-gliadin antibodies.(19)