Skin tests are medical procedures used to identify allergies or sensitivities to specific substances. During these tests, a small amount of the allergen, such as pollen or pet dander, is applied to the skin, usually on the forearm or back. The skin's reaction is then observed for redness, swelling, or itching, which indicates an allergic response. There are different types of skin tests, including skin prick tests, where a tiny prick introduces the allergen, and intradermal tests, which involve injecting a small amount of allergen just under the skin. These tests help healthcare providers diagnose allergies and guide treatment options.