Nickel allergy in patch-tested female hairdressers and assessment of nickel release from hairdressers' scissors and crochet hooks

Background: Hand eczema as well as nickel contact allergy is prevalent among hairdressers. Recently, two female hairdressers were diagnosed with nickel contact allergy-related hand eczema following prolonged skin contact with scissors and crochet hooks used during work.
Objectives: To determine the proportion of hairdressers' scissors and crochet hooks that released an excessive amount of nickel and to determine the prevalence of nickel allergy among patch-tested female hairdressers.
Materials: Random hairdressers' stores in Copenhagen were visited. The dimethylglyoxime (DMG) test was used to assess excessive nickel release. The prevalence of nickel allergy among female hairdressers from the database at Gentofte Hospital was compared with the prevalence of nickel allergy among other consecutively patch-tested dermatitis patients.
Results: DMG testing showed that 1 (0.5%; 95% CI = 0 − 2.0) of 200 pairs of scissors and 7 (53.8%; 95% CI = 26.0 − 82.0) of 13 crochet hooks released an excessive amount of nickel. The prevalence of nickel allergy was higher among middle-aged and older female hairdressers than among young female hairdressers.
Conclusions: The prevalence of nickel allergy was lower among young hairdressers in comparison to older hairdressers. This may possibly be a result of the European Union (EU) Nickel Directive or a consequence of a decreased use of nickel-releasing work tools in salons. When nickel allergic hairdressers present with hand eczema, their work tools should be investigated for nickel release.