Occupational and non-occupational allergic contact dermatitis to hair dyes in Greece. A 10-year retrospective study

Background Oxidative hair dyes are an important source of chemical exposure and a major risk factor for the development of occupational and non-occupational allergic contact dermatitis (ACD) worldwide. Objective To identify the frequency of common allergens associated with occupational and non-occupational ACD to hair dyes during the last 10 years, in Greece. Methods We retrospectively reviewed the medical records of patients with suspected ACD to hair dyes from 2010-2019. All patients with patch-test-confirmed ACD to hair dyes were evaluated. Results Out of 501 patients with suspected ACD to hair dyes, 362 had at least one positive reaction to hair dye allergens (62.4% were customers and 37.6% were hairdressers). The mean age of customers and hairdressers was 43.8 years and 30.8 years, respectively. Of the customers, 58.9% were exposed to dyes for >10 years and 61% of hairdressers for <5 years. The most common site of ACD among customers was the scalp (85%) and among hairdressers the hands (90%). p-Phenylenediamine (PPD) was the most common contact allergen (52.2%), followed by toluene-2,5-diamine, p-aminophenol, m-aminophenol, and ammonium persulfate. Conclusions Sensitization prevalences for PPD and cross-reacting allergens have increased in Greece during the last decade, regardless of occupational or non-occupational exposure to hair dyes.