Photopatch testing in Bogota (Colombia): 2011–2013

Summary Background Photopatch tests are used to diagnose photoallergic contact dermatitis and identify the causal agents. The frequencies of positive results and associated allergens vary by country; therefore, it is necessary to know the information specific to each country. Objective To establish the frequency of positive photopatch test results, and their relevance, in patients with suspected photoallergic contact dermatitis in a national dermatology centre located in Bogota, Colombia. Materials and methods One hundred patients investigated for possible photoallergic contact dermatitis were enrolled in the study. They were photopatch tested with a selected group of allergens, and occluded for 48 hours; the duplicate right‐hand panel was irradiated with 5 J/cm 2 ultraviolet ( UV)A . The readings were performed on day (D)2, D4 , and D6 , in accordance with the guidelines of the ICDRG , and the relevance was evaluated with the COADEX system. Results There were a total of 20 photopatch reactions in 15 patients, 95% of which were caused by UV filters, most frequently benzophenone‐3 (55%). Eight of the positive reactions (53.3%) appeared on D6 . Conclusions UV filters continue to be the most common causes of photoallergic contact dermatitis in our patients. Readings up to D6 (96 h after irradiation) are important to identify delayed positive reactions.