Background: Hairdressers are at risk for occupational respiratory diseases, but the risk factors, causal agents, and underlying mechanisms are not completely defined.
Aim: To describe the features of a large group of hairdressers consecutively referred to our center for suspected occupational asthma (OA) over an 8-year period, the type of occupational respiratory diseases, the etiologic agents, and the diagnostic tests.
Results: Forty-seven hairdressers (mean age, 25 years; range, 17 to 52 years) were studied. On the basis of the response to the specific inhalation challenge (SIC), 24 patients received a diagnosis of OA (51.1%), which was due to persulfate salts in 21 patients (87.5%), permanent hair dyes in 2 patients (8.3%), and latex in 1 patient (4.2%). Thirteen of these 24 patients (54.2%) also received a diagnosis of occupational rhinitis, which was due to persulfate salts in 11 patients (84.6%) and to paraphenylenediamine in two patients (15.4%). Patients with persulfate asthma had a long period of exposure to bleaching agents, a long latent period between the start of exposure and the onset of symptoms, and a prevalent eosinophilic airway inflammation in induced sputum. The skin-prick test with ammonium persulfate performed in a subset of patients gave negative results
Conclusions: In the present study, we confirmed that persulfate salts are the major agents involved in OA and occupational rhinitis in hairdressers. The positive response to the SIC in only a part of the population of symptomatic exposed workers, the period between the starting of exposure and the onset of symptoms, the type of response to the SIC, and the high frequency of association of asthma with other diseases such as dermatitis and rhinitis suggest an immunologic mechanism that remains to be elucidated.