Skin tests are used to identify numerous potential allergens. This includes airborne, food-related, and contact allergens. The three types of skin tests are scratch, intradermal, and patch tests.

Your doctor will typically try a scratch test first. During this test, an allergen is placed in liquid, then that liquid is placed on a section of your skin with a special tool – allergy applicator, that lightly punctures the allergen into the skin’s surface. You’ll be closely monitored to see how your skin reacts to the foreign substance. If there’s localized redness, swelling, elevation, or itchiness of the skin over the test site, you’re allergic to that specific allergen.