An office approach to the diagnosis of chronic cough.

Chronic cough is a common problem in patients who visit family physicians. The three most common causes of chronic cough in those who are referred to pulmonary specialists are postnasal drip, asthma and gastroesophageal reflux. The initial treatment of patients with cough is often empiric and may involve a trial of decongestants, bronchodilators or histamine H2 antagonists, as monotherapy or in combination. If a therapeutic trial is not successful, sequential diagnostic testing including chest radiograph, purified protein derivative test for tuberculosis, computed tomography of the sinuses, methacholine challenge test or barium swallow may be indicated. By using a standard protocol for diagnosis and treatment, 90 percent of patients with chronic cough can be managed successfully in the family physician's office. However, in some cases it may take three to five months to determine a diagnosis and effective treatment. For the minority of patients in whom this diagnostic approach is unsuccessful, consultation with a pulmonary specialist is appropriate.