Chronic Cough Due to Gastroesophageal Reflux Disease: Laryngoscopy
When GERD causes cough by irritating the larynx, laryngoscopy has the potential to demonstrate signs consistent with “reflux laryngitis” (eg, posterior laryngitis with red arytenoids and piled-up interarytenoid mucosa). Bronchoscopy and chest-imaging studies have the potential to detect abnormalities consistent with aspiration. Bronchoscopy may reveal airway signs consistent with aspiration (eg, subglottic stenosis,2 hemorrhagic tracheobronchitis, and erythema of subsegmental bronchi); chest-imaging studies may demonstrate a wide spectrum of parenchymal abnormalities. While laryngoscopic and bronchoscopic signs are consistent with reflux-induced injury, one must be cautious and not assume that merely observing changes consistent with inflammation and edema of the larynx and lower airways is specific for GERD because they may also potentially be due to the act of coughing itself that is provoked by other diseases. Link
When laryngoscopy, bronchoscopy, and chest-imaging studies are normal, it is assumed that GERD has caused cough by stimulating the esophageal-bronchial reflex. Multiple prospective clinical studies have suggested this latter pathophysiologic scenario to be the most common, Evidence is mounting (eg, prospective before-and-after, successful antireflux surgery intervention trial in patients who had previously failed to improve despite total/near-total elimination of esophageal acid; prospective, randomized, controlled pharmacologic studies; and randomized, controlled intra-esophageal acid/saline solution challenge studies) that there are likely to be multiple potential triggers of cough including, but not limited to, acid in the gastric refluxate, and the triggers of cough may differ among patients. While it is not known what the nonacid factors are, they may include- alkaline pH, pancreatic enzymes, bile, and esophageal dysmotil-ity. Because esophageal dysmotility can be commonly demonstrated in patients with GERD, it is not clear whether or when esophageal dysmotility is an adverse occurrence due to GERD or contributing to GERD.