Chronic persistent cough: diagnosis and treatment update.

The approach to patients with chronic cough has been well defined and evaluated in the literature through a number of prospective studies. Meticulous attention to detail of the afferent loop of the cough reflex has helped identify the cause of cough in most patients. The most common causes appear to be similar in both children and adults and include asthma, postnasal drip syndromes, gastroesophageal reflux diseases, and aspiration. In children, recurrent viral infections and infections with atypical organisms also are very prevalent. Specific therapy directed at the cause alleviates the cough in most patients. In some patients, there may be more than one cause of cough. Invasive testing (eg, bronchoscopy and esophageal pH probing) is rarely necessary. In patients in whom a specific cause cannot be identified or in whom cough modifiers are necessary while specific therapy is taking hold, antitussives of both the narcotic and nonnarcotic variety are helpful.