An international perspective on the demographic and clinical features of exercise induced laryngeal obstruction

Background: Exercise-induced laryngeal obstruction (EILO) is an important cause of exertional breathlessness and wheeze. Epidemiological understanding of EILO remains unclear and arises largely from Scandinavian countries. We provide the first international perspective on the demographic characteristics, laryngeal abnormalities and impact of EILO. Methods: Retrospective database review (from 5 expert centres in Denmark, UK, & USA), for patients undergoing clinical asthma and EILO work-up with continuous laryngoscopy during exercise (CLE) testing between 2014–2018. Results: A total of 1,007 individuals completed CLE, of these 586 (58%) demonstrated EILO. Demographic characteristics for cases with EILO were similar across centres; median age of 21 (80% were ≤ 34), a female preponderance (76%) and median 2-year delay to diagnosis; 20% were found to not have asthma despite prescription of inhalers. Half (49%) of subjects were elite athletes. Supraglottic EILO (i.e. collapse of the arytenoid structures) was the predominant form and only 18% had glottic level (i.e. vocal cord dysfunction [VCD]) closure. Conclusion: This international collaboration reveals similarities in the clinical characteristics of EILO highlighting delay to diagnosis, inappropriate asthma treatment and that exercise induced VCD is a misnomer. These findings help to further define this condition and improve clinician’s recognition.