It is the most severe allergic reaction to an allergen. Symptoms usually appear rapidly, sometimes within minutes of exposure to the allergen. Because they can be life-threatening, immediate medical attention is necessary when an anaphylactic reaction occurs. Food Allergy Diagnosis usually begins with a thorough medical history, a complete physical examination and selected tests to rule out underlying medical conditions not related to food allergy. Patients may also have to keep a food diary and record symptoms over a period of time.
Several tests are available to determine if a person is allergic to a certain food.
In skin-prick testing, a diluted extract of the suspected food is placed on the skin, which is scratched or punctured. A blood test can provide similar information as that obtained by skin testing. This test is performed by a board-certified allergist. These tests have enabled allergists to identify the most common allergens, and also to determine what foods and additives do not cause allergic reactions. If a food allergy is diagnosed, the only proven therapy is avoidance of the offending food.