Contact dermatitis is a red, itchy, often localized rash that can be caused by an allergic reaction to common day products such as soaps, jewelry, or fragrances as examples. While we can help treat contact dermatitis with medications, we would ideally like to find the ingredient that is causing the rash in order to minimize further irritation and discomfort. The way we can identify whether common allergens are reacting with the skin is through patch testing. Patch testing is a procedure we perform in the office that utilizes standardized haptens that could cause contact dermatitis. In our office, we use the North American 80 series of allergens to identify skin reactions caused by many common chemicals. If interested in patch testing, understand that it requires multiple office visits including the placement of the patches to the back as well as the initial and delayed readings. If any positive reactions are identified, we counsel our patients and provide them with information sheets about the allergen and common products that can be found to help them avoid them in the future.