Unmasking nonasthmatic eosinophilic bronchitis as an important cause of chronic cough

Nonasthmatic eosinophilic bronchitis (NAEB) ranked third among the most common causes of chronic cough in China, however, it could be a comorbidity of upper airway cough symptom and gastroesophageal reflux cough. Chronic cough is the predominant or sole presenting complaint of NAEB. Normal lung function and negative bronchial hyper-responsiveness with airway eosinophilia (as evidenced by induced sputum, bronchoalveolar lavage or bronchial brushing) is diagnostic of NAEB pending on good clinical response to inhaled corticosteroids. At present the dose and course of inhaled corticosteroid therapy could not be recommended, though inhaled budesonide at a dose of 400μg bid for at least 4 weeks has been suggested, and short course oral corticosteroid is recommended when necessary. Add-on montelukast could reduce cough symptom, alleviate airway eosinophilia and reduce the dosage of inhaled corticosteroids. Exposure to low concentration of aeroallergens might play an important role in the pathogenesis of NAEB, and difference in the site of mast cell infiltration might have pivotal role in the pathophysiological difference between NAEB and asthma. DOI: 10.11855/j.issn.0577-7402.2014.05.07