Eosinophilic bronchitis: update and review

Abstract

Eosinophilic bronchitis (EB) is a common cause of chronic cough, which shares similar airway eosinophilic inflammation with asthma, however, there is no airway hyperresponsiveness and airflow obstruction. The mechanism of the different phenotype between EB and asthma remains unclear. The differences in the location of airway inflammation, the level of inflammatory mediators, the imbalance of important metabolic pathways, and the degree of airway remodeling may result in different pathogenesis between EB and asthma. EB response well to inhaled corticosteroids but recurrence of EB is still high after treatment. The longer duration of treatment with inhaled corticosteroids could decrease the relapse rate. On the prognosis of EB, a long-term follow-up study suggested that EB should be a distinct entity rather than an early stage of asthma or chronic obstructive pulmonary disease.