A 69-year-old woman presents with complaint of chronic cough. She is a former smoker, but quit over 20 years ago. She is healthy except for hypertension, for which she takes amlodipine; she is on no other medications. The cough has been present for 6 months. She produces scant clear sputum in the morning and denies hemoptysis or weight loss. The cough is more prominent at night. It is not exacerbated by exercise or cold exposure. There is no exposure history to potential lung toxins. She denies runny nose, nasal allergies, or postnasal drip. She has occasional heartburn, promptly relieved by two tablets of calcium carbonate. Physical examination and PA/lateral chest x-ray are normal. What is the next best step in the evaluation of this patient?
A. Therapeutic trial of proton pump inhibitorChronic cough is a common problem encountered in the clinic. Although patients are often worried about serious disease such as lung cancer, emphysema, or tuberculosis, these dire diagnoses are rare in the absence of a compatible history and chest x-ray. The commonest causes are (1) acid reflux (with inflammation of the larynx and trachea); (2) postnasal drip syndrome; (3) cough-variant asthma; and (4) drug-induced cough due to angiotensin-converting enzyme inhibitors (ACEIs). Extensive testing such as CT scanning, bronchoscopy, or esophageal pH monitoring is not recommended. The practitioner should make the best diagnosis on the basis of initial data, and then institute a therapeutic trial, understanding that a response often takes weeks or months. This patient’s nocturnal symptoms and occasional postprandial reflux (patients often do not have severe symptoms of GERD) would direct you toward a trial of PPIs. If she had allergic symptoms or cobblestoning of the posterior pharynx, a trial of nasal steroids/decongestants would be reasonable. Childhood asthma, intermittent wheezing, or exacerbation of symptoms with exercise or cold exposure would direct you toward a therapeutic trial of bronchodilators. Spirometry is usually normal unless the patient is having symptoms at the time of examination; methacholine challenge can be employed in selected patients. Amlodipine does not cause drug-induced cough. If the patient does not respond to high-dose PPIs, other therapeutic trials might be instituted.