What to do when patch test is negative: Making the best of your test and allergen selection

In a session directed by Amber Atwater, the discussion centers on what to do when patch test results are negative, which can be a challenging scenario in diagnosing allergic contact dermatitis. Dr. Marjorie Montanas Wiscovich outlines a three-step approach: first, considering the need to repeat the same test if there are doubts about allergen quality or testing technique; second, testing additional allergens based on patient history to increase the chance of identifying the culprit; and third, possibly reassessing the diagnosis if necessary. Key factors affecting test results include allergens' storage conditions, concentration levels, patch adhesion quality, and patient factors such as active dermatitis or recent sun exposure. Methods to enhance diagnosis may include additional tests like open application testing and using extended allergen series. Dr. Wiscovich emphasizes the importance of managing patient expectations regarding the possibility of negative results, highlighting the inherent limitations of patch testing despite its status as the gold standard for identifying contact allergies. Ultimately, a thorough clinical history and follow-up readings play essential roles in accurately diagnosing allergic contact dermatitis.