Patch testing is a test used to determine if you are allergic to something coming in direct contact with your skin. The most common allergens are fragrances and preservatives found in personal care products such as shampoos, soaps and detergents. The test is pain free, and no needles are involved. Adhesive patches are applied to the patient’s back in the office, where they remain in place for 48 hours. Once removed, positive reactions are noted and patients are educated about what they are allergic to and which products are safe for them to use. At South Nassau Dermatology, we have an extensive panel of over 125 of the most common allergens. The test has proven life changing for patients with recurrent itchy rashes that look like eczema, but are actually allergic contact dermatitis.