Clinical Characteristics and Impact of Inducible Laryngeal Obstruction in the UK National Registry.

Background: Inducible laryngeal obstruction (ILO) describes inappropriate laryngeal closure during respiration, with airflow obstruction occurring at the glottic and/or supraglottic level, leading to breathlessness.

Objective: There is a paucity of data describing the demographics and impact of ILO. We aimed to report the clinical and demographic features of ILO in individuals entered prospectively in the UK national ILO registry.

Methods: Data were entered into a Web-based registry from participants with endoscopically confirmed ILO who were attending four established UK-wide specialist ILO centers between March 2017 and November 2019. All patients provided written informed consent.

Results: Data from 137 individuals were included. Most (87%) had inspiratory ILO and required provocation during endoscopy to induce symptoms. There was a female predominance (80%), mean age 47 years (SD, 15 years). The most common comorbidities included asthma (68%) and reflux (57%). Health care use was high: 88% had attended emergency health care with symptoms at least once in the previous 12 months and nearly half had been admitted to the hospital. A fifth had required admission to critical care owing to ILO symptoms. Patient morbidity was substantial; 64% reported impaired functional capacity (≥3 on the Medical Research Council Dyspnoea Scale) and a third stated that symptoms affected working capability.

Conclusion: We describe the first multicenter prospective characterization of individuals with endoscopically diagnosed ILO. Analysis of our multicenter data set identified ILO as associated with a high burden of morbidity and health care use, comparable to severe asthma. These data will support the development of health care resources in the future and guide research priorities.