How often is chronic cough due to laryngopharyngeal reflux (LPR)? Are proton-pump inhibitors prescribed for gastroesophageal reflux disease (GERD) effective in the treatment of chronic cough?
—Charles S. Winans, MD, Chicago
LPR is thought to be a disorder of the upper esophageal sphincter and can be defined as the retrograde movement of gastric contents into the laryngopharynx. Symptoms of LPR often manifest as disorders of the larynx/hypopharynx, such as hoarseness, globus sensation, and chronic cough. In contrast to GERD, which is thought to be related to dysfunction of the lower esophageal sphincter, only about 35% of patients with LPR report heartburn (Ear Nose Throat J. 2002;81[9 Suppl 2]:7-9). However, both LPR and GERD are in the differential diagnosis for chronic cough, and both should be carefully considered in the patient with chronic cough and no obvious alternate etiology. Various studies have estimated that GERD accounts for 20%-40% of the incidence of chronic cough, but these epidemiologic data typically do not distinguish GERD from LPR as a distinct etiology, so the frequency of chronic cough due to LPR is not clear. Although proton-pump inhibitors are often used to treat LPR, there is limited evidence of their efficacy for this disorder. A prospective randomized trial comparing twice-daily esomeprazole 40 mg with placebo for 16 weeks failed to find a significant difference in symptoms at the end of the study (Laryngoscope. 2006;116:254-260).
—Daniel G. Tobin, MD (111-8)