Hand contact dermatitis in hairdressers: clinical and causative allergens, experience in Bangkok.

Hand dermatitis in hairdressers is a common occupational contact dermatitis. Irritant contact dermatitis is thought to be more common. To investigate the causes of hand dermatitis, common allergens, clinical patterns, morphology and onset of lesions among hairdressers. Forty four hairdressers who were diagnosed with hand dermatitis in a dermatological outpatient department were included and investigated by patch testing with standard and hairdressing related allergens and/or prick test. Allergic contact dermatitis was diagnosed with a positive patch test reaction in 33 cases (75%), irritant contact dermatitis was found in 11 cases (25%). The clinical manifestations were mostly scaly plaques (68.18%) or vesicles (50%). The most common site of involvement was the palms (38.63%). The common causative allergens were paraphenylenediamine (45.45%), nickel (31.18%), fragrance mix (20.45%), p-toluenediamine sulphate (18.18%), ammonium persulfate (13.63%), and p-aminophenol (13.63%). Allergic contact dermatitis is more common among hairdressers, PPD was the most common causative allergen in our study.