Abstract

Chronic cough is a common significant health problem. Upper airway cough syndrome, asthma and gastroesophageal reflux disease are thought to be the most common causes of chronic cough in adults. Cause-directed treatment is the mainstay of the current diagnostic approaches for chronic cough. However the empiric therapy because of its simplicity and less expense has also been accepted as a surrogate for cause-directed therapy. Algorithms integrating diagnostic protocol and empiric therapy are advocated for the management of chronic cough patients in guidelines. However many clinics report a significant percentage of patients with unexplained (idiopathic) chronic cough despite detailed investigations and treatment trials. There is agreement among some clinicians that idiopathic chronic cough should be considered as a disorder rather than just a symptom. Recently, cough reflex hypersensitivity has been advocated as the underlying mechanism of idiopathic cough. There is pressing need to understand the pathogenesis of idiopathic cough and to develop novel antitussive drugs that down regulate cough reflex hypersensitivity.