Allergic contact dermatitis is an itchy skin condition (rash) caused by an allergic reaction to material (the allergen) in contact with the skin. It arises some hours after contact with the responsible material, and settles down over some days providing the skin is no longer in contact with it. Sometimes it is easy to recognize what allergen contacted the skin and no specific tests are necessary. The rash usually (but not always) completely clears up if the allergen is no longer in contact with the skin, but recurs even with slight contact with it again. To treat contact dermatitis successfully, you need to identify and avoid the cause of your reaction.
Dermatology providers apply patch tests in patients with allergic contact dermatitis to find out whether their skin condition may be caused or aggravated by a contact allergy. Patch testing helps identify which substances may be causing the allergic reaction in a patient, and may identify allergens not identified by blood testing or skin prick testing. It is intended to produce a local allergic reaction on a small area of the patient's back, where the diluted allergens are placed.
At Arkansas Dermatology, patch testing involves ready-to-use substances placed onto a small disc (a patch) that is then taped onto the outside of your skin, usually on your back. There is no pricking or injecting of substances into the skin. The discs contain different substances or mixes, all of which are well-known causes of contact dermatitis. You will be tested to numerous ingredients that are selected based on your history and skin findings.
A skin patch test is designed to help your provider determine whether or not you are allergic to any of the substances included on the discs. We may also be able to test you to your individual skin care products if necessary.