Pathophysiology, Causes and Treatment of Chronic Cough in Adults: Literature Review

Abstract

Received September 1, 2014 Accepted June 23, 2015 Address for correspondence Myung-Whun Sung, MD, PhD Department of Otorhinolaryngology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 03080, Korea Tel +82-2-2072-3830 Fax +82-2-745-2387 E-mail mwsung@snu.ac.kr Chronic cough is a common symptom and the etiology of which can be challenging to diagnose. The key to successful management is to establish a diagnosis and to treat the cause of cough. Asthma, gastro-esophageal reflux, and postnasal drip syndrome have been thought to be most common causes of chronic cough. Various causes such as lung diseases (sarcoidosis, pertussis), obstructive sleep apnea, drug (angiotensin-converting enzyme inhibitor), and psychological status can induce chronic cough. However, many chronic cough patients do not have an identifiable cause. We need to understand the mechanisms underlying central and peripheral sensitization, how they interact with cough triggers and their relationship with the sensations that drive the urge to cough, and the subsequent motor cough response in chronic cough. Heightened cough reflex sensitivity is persistent and their cough is unexplained in many patients. In most patients who visited otorhinolaryngoloy clinics, it is possible to manage a majority of chronic cough patients successfully using a protocol based on presenting symptoms and therapeutic trials for the common causes of cough. However, there are few therapeutic options for patients with unexplained chronic cough. There is a pressing need to understand the physiological basis of unexplained chronic cough and to develop novel antitussive drugs that down regulate cough reflex sensitivity. Korean J Otorhinolaryngol-Head Neck Surg 2015;58(11):744-53