Patch Test Results to European Baseline Series in Turkey: A Prospective and Multicenter Study

Background Patch testing with the European Baseline Series (EBS) is an essential diagnostic tool for the assessment of allergic contact dermatitis. Objective The aims of the study were to describe the most common contact allergens identified with patch testing in Turkey and to establish the distribution of contact allergens among different regions in Turkey. Patients and Methods Twelve centers consisting of tertiary health care institutions were included in the study. A total of 1169 patients were patch tested with the EBS from 2015 to 2017. Results A total of 596 patients (51.0%) had 1 or more positive patch test reactions to the EBS. A total of 30.2% (n = 353) of those tested had clinical relevance. Contact sensitivity was more common in young patients. The most common 10 allergens were nickel sulfate (20.4%), followed by textile dye mix (8.6%), cobalt chloride (8.3%), potassium dichromate (8.0%), p-phenylenediamine base (4.5%), balsam of Peru (4.3%), methylchloroisothiazolinone/methylisothiazolinone (3.8%), thiuram mix (3.6%), fragrance mix I (3.0%), and methylisothiazolinone (2.9%). Conclusions This study provides a comprehensive profile of patch test results with the EBS in Turkey. An ongoing decrease in contact allergy to methylchloroisothiazolinone/methylisothiazolinone and methylisothiazolinone was observed. Textile dye mix and p-phenylenediamine are beginning to pose a new risk in Turkey.