Contact dermatitis in hairdressers, 10 years later: Patch-test results in 300 hairdressers (1994 to 2003) and comparison with previous study

Background: In the last 20 years, the hairdressing profession has undergone important modifications, mainly because of a change in the substances and techniques used and improved occupational education. Objective To evaluate the modifications in the hairdressing profession and its actual risk of occupational allergic contact dermatitis (OACD). Methods: We studied all 300 hairdressers seen in our department from 1994 to 2003 and compared the results with those of a previous study of 379 hairdressers who attended our department from 1980 to 1993. All were patch-tested with the European Standard series and specific hairdressing products. As previously, most of the workers were women (93%), with a mean age (23.7 years) slightly higher than that of the workers in our previous study. Results: We found a significant increase in the frequency of positive patch-test responses (78.3% vs 58.8%) and OACD (58% vs 48.8%) with respect to our previous study. We also observed a significant increase in sensitization to most allergens, including p-phenylenediamine base (54% vs 45.9%), 4-aminobenzene (40.7% vs 31.9%), ammonium thioglycolate (2.7% to 12.3%), ammonium persulfate (7.9% to 14.3%), p-toluenediamine sulfate (6.8% to 15.3%), p-aminodiphenylamine (2.9% to 7.7%), o-nitro-4-phenylenediamine (2.1% to 7.3%), and aminophenols (0% to 9%), whereas a decrease was found in sensitization to Disperse Orange (17% vs 32.7%) and thioglycolic acid (15.3% to 3%). Conclusion: The high frequency and increase of sensitizations among hairdressers require urgent measures to improve protective measures and their application.