Work

‘The prevalence of exercise-induced laryngeal obstruction (EILO) among children with asthma’: a study protocol of a prospective cross-sectional study

Year: 2026

Type: article

Abstract: Introduction Exercise-induced symptoms are common within the paediatric population and can hamper participation in sports and play, negatively impacting cardiorespiratory activity and social interaction. Exercise-induced bronchoconstriction (EIB) is a prevalent and well-known cause of exercise-induced symptoms. Especially in children with asthma, exercise-induced symptoms are often primarily attributed to EIB, although other causes of exercise-induced symptoms are numerous. In patients with exercise-induced laryngeal obstruction (EILO), narrowing of the larynx during exercise causes symptoms similar to those of EIB. The reported prevalence of EILO among adults with asthma ranges from 13% to 47%, whereas EILO prevalence among the general adolescent population is 5%–8%. Currently, the prevalence of EILO among asthmatic adolescents has not yet been investigated. In this study, we aim to investigate the prevalence of EILO among adolescents with asthma. Knowledge of EILO prevalence in this specific group can help to determine the position of the continuous laryngoscopy during exercise (CLE) test in diagnostic guidelines for adolescents with asthma.Methods and analysis This study protocol describes a prospective cross-sectional study that aims to include 200 participants from the outpatient paediatric department of Medisch Spectrum Twente (Enschede, The Netherlands) and Haukeland University Hospital (Bergen, Norway). Consecutive participants referred for an exercise challenge test (ECT) to evaluate their asthma will be informed and asked to participate. Reasons for non-participation or exclusion will be registered. Participants are eligible for inclusion if they are between 12 and 18 years of age and have asthma confirmed with at least one objective lung function test during the last 2 years. Demographic background variables and comorbidities will be collected. Included children will undergo both an ECT and CLE test within a time frame of 1 month. The primary outcome is the prevalence of EILO in the study population of adolescents with asthma, calculated as a percentage with a 95% CI.Ethics and dissemination Ethical approval has been granted and the study is registered at ClinicalTrials.gov ( NCT06480084). Study results will be presented at medical conventions and in peer-reviewed scientific journals.

Source: BMJ Open Respiratory Research

DOI: 10.1136/bmjresp-2025-003518