Photopatch Testing of 182 Patients: A 6-Year Experience at the Mayo Clinic

Background: Photopatch testing is important for diagnosing photoallergic contact dermatitis. Although results of photopatch testing have been presented from many European centers, there have been few reports of the results of photopatch testing in the United States. Objective: To review the Mayo Clinic's recent experience with photopatch testing, identify common photoallergens, and compare our current and previous findings. Methods: We retrospectively reviewed records of patients who underwent photopatch testing at the Mayo Clinic between January 1, 2000, and December 31, 2005 (N = 182). Results: Fifty-four patients (29.7%) had photoallergic contact reactions, and 29 (15.9%) had allergic contact reactions. The most common photoallergens were medications, sunscreen agents, fragrances, and antiseptics. Conclusion: Photopatch testing is the technique useful in identifying photoallergens. The series of allergens used must be constantly updated to reflect newly identified and outdated photoallergens. We present a 6-year experience with photopatch testing. Medications, sunscreen agents, fragrances, and antiseptics were the most frequently identified photoallergens.