Pathophysiological mechanisms of extraesophageal reflux in otolaryngeal disorders

As more than 40% of adults experience symptoms of the gastroesophageal reflux (GER) and 26% are affected by the extraesophageal reflux (EER), the aim of this article was to review the literature concerning pathophysiological mechanisms contributing to these common diseases. Reflux symptoms are ascribable for nearly one-third of otolaryngeal disorders. In contrast to patients solely affected by GERD, patients with otolaryngeal disorders attributable to extraesophageal reflux have a relatively good esophageal acid clearance but for unknown reasons increased amounts of laryngeal reflux. Transient upper esophageal sphincter relaxations are discussed as the pathophysiological mechanism, as the resting tone of the upper esophageal sphincter is not affected. When exposed to gastroduodenal contents, the ciliated epithelium of otolaryngeal structures is more susceptible to damage, and thereby even a few reflux episodes are suggested to cause extraesophageal reflux disease (EERD). Particularly active pepsin contributes to laryngeal lesions and eustachian tube dysfunction. Despite the importance of EER in laryngeal diseases, the causative role in other otolaryngeal disorders like sinusitis and otitis media with effusion remains unresolved.