Chronic cough: Diagnosis and treatment

Cough is a common symptom in the smoking and non-smoking patient seeking medical attention from the office-based physician. Often, a comprehensive history and physical examination suggest the correct diagnosis, and specific therapy can be directed to the underlying disease. A chest roentgenogram is an essential part of the workup; it may suggest tuberculosis, chronic fungal infection, bronchiectasis, or lung abscess. In addition, bronchogenic carcinoma, which is increasing in frequency in the population, has several common manifestations that can be recognized on the chest roentgenogram. Pulmonary function studies are often helpful in the workup of the patient with chronic cough. A pattern of obstructive lung disease is seen with asthma, chronic bronchitis, and bronchiectasis. Diseases that cause lung fibrosis, such as idiopathic pulmonary fibrosis, sarcoidosis, and pneumoconiosis, give a restrictive ventilatory defect. Bronchoprovocation testing can be helpful when baseline pulmonary function tests are normal and the diagnosis of postviral bronchitis or cough-variant asthma is suggested. If the bronchial inhalation challenge is negative, these diagnoses can be excluded. Chronic rhinosinusitis with associated postnasal drip is one of the most common causes of chronic cough and is often difficult to confirm because the physical examination and roentgenogram of the paranasal sinuses may be normal. In a great majority of patients with chronic cough, a diagnosis can be established by simple, clinical and laboratory procedures used in the outpatient setting.