Exercise-Induced Laryngeal Obstruction

The investigators propose a study that compares breathlessness and airway obstruction during intense exercise in 34 children and adolescents with Exercise-Induced Laryngeal Obstruction after breathing in ipratropium bromide or placebo. It is hypothesized that breathlessness and airway obstruction will be lower following breathing in ipratropium bromide compared with placebo.

The goal of this cross-sectional study is to investigate the prevalence of Exercise Induced Laryngeal Obstruction (EILO) in children with asthma. The hypothesis is that the prevalence will be around 15%, which is higher than the prevalence of 5-8% among the general adolescent population. This is based on the increased prevalence of EILO among adult asthmatics. Participants who are referred for an Exercise Challenge Test will perform an additional Continuous Laryngoscopy during Exercise Test with expiratory FEV1 curves, and fill in the Borg scale for dyspnea, Asthma Control Test, EILODI questionnaire and DISCO-RC questionnaire.