ALLERGY SKIN TESTING Skin Test Skin tests are a method of testing for allergic antibodies. A test consists of applying small amounts of the suspected substance, or allergen, onto the skin and noting the development of a positive reaction (which consists of a wheal, swelling, or flare in the surrounding area or redness). The results are read 15 to 20 minutes after application of the allergen. The skin test methods used are: Prick Method: The skin is pricked where a drop of allergen has already been placed. Intradermal Method: This method consists of injecting small amounts of an allergen into the superficial layers of the skin. Multi-Test Method: Allergen solutions are placed on the individual prongs of a multi-prong plastic device which is placed firmly on the back for 5 to 10 seconds, then removed. (this test is typically used on children) The Prick Test is the method of allergy testing to which most other tests are compared to. Prick tests are performed on the back and intradermal tests are performed on the upper arms. If there is a specific allergic sensitivity to one of the allergens, a red, raised, itchy wheal (caused by histamine release into the skin) will appear on the skin usually within 15-20 minutes. These positive reactions will gradually disappear over a period of 30-60 minutes, and normally no treatment is necessary for the itching. Hydrocortisone cream can be applied to these areas after testing if the itching persists. Occasionally, local swelling at a test site will being 4 to 8 hours after the skin tests are applied, particularly at sites of intradermal testing. These delayed responses are not serious and will disappear over the next week or so. They should be measured and reported to the Allergist at the patient's next visit. Severe allergic responses may occur during allergy skin testing. If a severe reaction might occur, a fully trained staff and emergency equipment is available. Interpreting the clinical significance of skin tests requires skillful correlations of the test results with the patient's clinical history. Positive tests indicate sensitization, the presence of allergenic antibodies, and are not necessarily correlated with clinical symptoms.