The Three Types of Skin Tests

As previously mentioned, there are three types of skin tests that one can perform in order to identify allergens. The first is a skin prick test. This is done by pricking the skin with a needle, just deep enough so that the droplets of suspected allergen solutions can get into the skin when placed on the pin prick holes. If the person’s skin becomes red, raised and itchy at the site of the allergen placement, then it is taken to mean that the person tested is positively allergic to that specific allergen. The next kind of test is an intradermal test, which is performed when the skin prick test comes up negative but a substance is still suspected of being an allergen.

When performing this test, a tiny amount of that specific allergen solution gets injected into the skin. Because of this, this test is more sensitive than the first, and can often lead to positive results in people that don’t have allergies due to its invasive nature. This is known as a false positive. Lastly, there is the skin patch test. In this test the allergen solution is applied to a pad that is then bound to the person’s skin for between 24 and 72 hours. This test is specifically used to detect an annoying skin allergy known as contact dermatitis.