The gold standard for the diagnosis of allergic contact dermatitis is patch testing, during which allergens are affixed to the skin underneath tape and left for multiple days. A large area of clear skin is thus required for successful testing. While the back is traditionally thought to be the ideal area for testing, the thighs may be more available or advantageous. This study seeks to randomize patients undergoing patch testing to have patches placed on the back or the thighs. The investigators seek to understand the benefits of testing on the legs versus the back in terms of patient experience as well as achieving a successful test. This study will measure patient experience using a survey administered to patients. Quality of testing will be assessed by study coordinators prior the removal of patches.