Abstract
Introduction: Chronic cough is a common cause for consultation, often view as a difficult clinical problem. A stepwise approach may be useful to avoid performing expensive and sometimes invasive tests in many patients. The measurement of exhaled nitric oxide (FeNO) is currently used to assess airway inflammation with an eosinophilic component especially in asthma. Nevertheless, its place for the investigation of chronic cough is still debated.
The aim of this study was to assess the prevalence of high FeNO in chronic coughing patients and to describe their clinical, etiologic and functional characteristics.
Methods: One hundred patients referred for assessment of chronic cough underwent a FeNO measurement at the same time than a first line exploration by thoracic imaging and spirometry or plethysmography .
Results: Twenty five patients had a high FeNO (over 25ppb). For four of them, a specific diagnosis (COPD, Bronchiectasis, Interstitial disease) was made after the first line exams. Among the 21 remaining patients, 3 were considered as asthmatic and 6 had a cough-variant asthma after metacholine challenge was performed. Twelve patients didn't have any bronchial hyperreactivity. All of them received an inhaled corticosteroid treatment. Improvement was observed in 10 of them.
Conclusions: Exhaled NO measurement is an interesting and easy tool to use in the first line exploration of chronic cough beside chest imaging and lung function tests. It allows to identify patients with high FeNO who can get few complementary investigations. In these selected patients, inhaled corticosteroids are usually effective.
- © 2014 ERS
