Not all that wheezes is asthma - videolaryngoscopy during bicycle ergometry in children and adolescents

Abstract

Background:

Exercise-induced laryngeal obstruction is not uncommon in children and adolescents. Condition presents with distressing symptoms and is many times misdiagnosed as asthma. Our aim was to directly visualize the larynx during exercise in patients with the history of dyspnea and inspiratory stridor on exertion.

Methods:

We combined continuous flexible transnasal laryngoscopy with bicycle ergometry. Data from 37 consecutive patients were analysed; prior medical history and functional tests, larygeal endoscopic findings and ergometry results were assessed. Selected patients were further referred for laryngeal sensory testing.

Results:

All 37 subjects (22 female) completed the test. Their median age was 13.3 years (range 9-21 years). Seventeen were atopic, 18 were active athletes (mostly cyclists and swimmers with 6 and 3 subjects respectively). Exercise-induced laryngeal obstruction was diagnosed in 25 (60% female). Ten among them were atopics and the same number (40%) was treated for presumed asthma. Only one had moderate to severe bronchial hyperresposivness (p = 0.05), none had elevated exhaled nitric oxide (p = 0.03). No adverse reactions were recorded. Laryngeal sensory testing was performed in 22 subjects. Hypersensitivity was detected in 15, hyposensitivity in 1, 4 had normal results, 2 couldn't tolerate the test.

Conclusions:

Flexible videolaryngoscopy during bicycle ergometry can be performed safely in children and adolescents. It is a valuable diagnostic tool for assessment of possible exercise-induced laryngeal obstruction. Altered laryngeal sensitivity for mechanical stimuli might explain exercise-induced dynamic upper airway obstruction.