Exposures and reactions to allergens among hairdressing apprentices and matched controls

Objectives. To estimate the degree of exposure and adverse skin reactions to chemical substances in a cohort of hairdressing apprentices, at the start of their education, as compared with a matched sample from the general population. Materials. During their first 2 weeks of training, 382 hairdressing apprentices were enrolled in this study. All apprentices completed a self-administered questionnaire that included questions regarding, for example, exposures and skin reactions to hair dye, perfumed products, and piercings. For comparison, the questionnaire was sent to a control group from the general population, matched on age, sex, and postal code (n = 1870). Results. Within the previous year, 95.2% of hairdressing apprentices and 66.9% of the control group had dyed their hair (p < 0.001); the apprentices dyed their hair, on average, 6.6 times per year, as compared with 3.7 times per year in the control group (p < 0.001). The mean age of the first hair dying among the apprentices was 12.1 years, as compared with 13.3 years for the matched control group (p < 0.001). The hairdressing apprentices reported more eczematous reactions to hair dye (p = 0.002) than the controls. Semi-permanent so-called 'black henna tattoos' had been carried out in 48.1% of the apprentices, as compared with 31.0% of the controls (p < 0.001). Conclusions. Both hairdressing apprentices and the matched control group of young people from the general population were highly exposed to potent allergens. The hairdressing apprentices were even more exposed to products containing hair dye substances and piercings, and reported more adverse reactions to hair dye products than their matched controls from the general population.