Observational study of the natural history of eosinophilic bronchitis

Summary Background Eosinophilic bronchitis is an important cause of chronic cough. Treatment with inhaled corticosteroids is associated with a short‐term improvement in cough and reduced sputum eosinophil count but the long‐term outcome is uncertain. Objective To determine the long‐term outcome in patients diagnosed with and treated for eosinophilic bronchitis. Methods We have performed a longitudinal study of symptoms, eosinophilic airway inflammation, spirometry and airway hyper‐responsiveness in all patients diagnosed with eosinophilic bronchitis over 7 years. Results We identified 52 patients with eosinophilic bronchitis and longitudinal data of greater than 1 year (mean 3.1 years) was available in 32 patients, all of whom were treated with inhaled steroids. Three (9%) patients developed symptoms consistent with asthma and a methacholine PC20