Irritable Larynx Syndrome

Irritable larynx syndrome (ILS) was first described by Murray Morrison and colleagues as a comprehensive theoretical framework to account for the clinical presentation of laryngeal hyper-responsiveness. A central thesis of the ILS theory is that laryngeal irritation is inevitable in all individuals. Everyone experiences postnasal drip, gastroesophageal reflux/laryngopharyngeal reflux, and cough from time to time. Most individuals maintain tolerance to irritating agents in the laryngeal and ambient environments without developing chronic laryngeal behaviors. ILS occurs when the threshold of tolerance to the irritation is surpassed.

The larynx has chemoreceptors and pressure receptors, both of which send signals back to the brain about the presence of irritants or potentially life-threatening substances. Presence of irritants or life-threatening agents may trigger a range of laryngeal responses from a throat ...