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

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. 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. 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. 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.

Pala G ，Pignatti P ，Moscato G 《-》

Increased S-nitrosothiol levels in nonasthmatic eosinophilic bronchitis compared with cough variant asthma.

Nonasthmatic eosinophilic bronchitis (NAEB) and cough variant asthma (CVA) are common causes of chronic cough. Both are characterized by eosinophilic inflammation in the airways. However, airway hyperresponsiveness, which is a characteristic feature of CVA, is not observed in NAEB. We hypothesized that endogenous bronchodilator S-nitrosothiol (SNO) levels are different between patients with NAEB and CVA. SNO concentrations in sputum supernatant were measured using a commercially available kit in 20 NAEB and 21 CVA patients. The mean sputum eosinophil counts and exhaled nitric oxide values were similar in patients with NAEB (12.4 ± 2.3%, 80.6 ± 8.1 ppb) and CVA (15.3 ± 3.7%, 97.7 ± 9.2 ppb). By contrast, SNO levels in the airway lining fluid of NAEB patients were substantially higher than those of CVA patients (87.1 ± 9.8 vs. 46.8 ± 4.8 μM; p < 0.05). SNOs may be an important factor in determining the development of airway hyperresponsiveness in the presence of eosinophilic inflammation.

Lee BJ ，Jeung YJ ，Lee JY ，Choi DC ... -  《-》

Exhaled nitric oxide measurement is useful for the exclusion of nonasthmatic eosinophilic bronchitis in patients with chronic cough.

Oh MJ ，Lee JY ，Lee BJ ，Choi DC ... -  《CHEST》

Occupational exposure to toluene diisocyanate and neutrophilic bronchitis without asthma.

Pala G ，Pignatti P ，Moscato G 《-》

Exhaled nitric oxide in evaluation of young adults with chronic cough.

Kowal K ，Bodzenta-Lukaszyk A ，Zukowski S 《-》