The use of fractional exhaled nitric oxide in investigation of work-related cough in a hairdresser.

BACKGROUND Occupational and environmental factors may be a cause of nonasthmatic eosinophilic bronchitis (NAEB). The diagnosis of occupational NAEB requires evidence of sputum eosinophilia. Nevertheless, a minority of patients are not able to produce suitable sputum specimens. METHODS This case report describes a 25-year-old woman, working as a hairdresser since the age of 20 years and handling ammonium persulfate, who came under our observation for work-related rhinitis and cough. RESULTS A specific inhalation challenge with ammonium persulfate elicited dry cough, without any significant change in forced expiratory volume in 1 s (FEV(1) ). Sputum induction was unsuccessful both pre- and after specific inhalation challenge. Fractional exhaled nitric oxide (FeNO) values significantly increased after specific inhalation challenge, suggesting a diagnosis of occupational NAEB due to ammonium persulfate. CONCLUSIONS From this observation we suggest that FeNO measurement should be added to the investigation of work-related cough during specific inhalation challenge, and may be considered as an alternative to induced sputum to evaluate bronchial inflammation when sputum collection is unavailable or unsuccessful.