San Diego Allergy, Asthma & Immunology Consultants, Inc
(Food Allergy Testing, Food Intolerance, Gluten Sensitivity)
Allergy testing is considered by most Board-Certified Allergists to be the best way to identify your allergens. Allergy testing is performed by scratching/pricking a small amount of allergen into your arm and seeing how much reaction it causes within 15 minutes. The reaction is caused by the interaction between the allergens, allergy antibodies (IgE) and your immune cells (mast cells.) Mast cells release histamine and other chemicals, causing itching, swelling, and redness at the site of the skin test.
Testing involves being “pricked” with several plastic Multitest devices. Each white Multitest device has 8 skin testing prongs. Each prong is dipped in a well and each well contains a different food allergen. 15 minutes later, the results are written down and interpreted. Interpretation involves measuring the wheal and flare response to each of the allergens which were tested. Usually (but not always), the larger the wheal and flare response, the worse the allergy. The wheal is the raised area of skin. The flare is the red area of skin surrounding the wheal. Your testing sheet will indicate the size of the wheal and the size of the flare. For example, a result of 5/15 for alder tree indicates that there was a 5 mm wheal and a 15 mm flare.
One of the testing prongs contains histamine, which is used as a positive control. Another prong contains saline, which is used as a negative control.