Inducible laryngeal obstruction (ILO) refers to respiratory disorders caused by airflow limitation in the larynx, including vocal cord dysfunction, and may sometimes be misdiagnosed as bronchial asthma (BA). Here, we report the case of an 11-year-old boy diagnosed with BA in infancy. He was referred to our Allergy Center and was taking a high dose of inhaled corticosteroids (ICS) due to frequent coughing from the age of 10 years and persistent coughing following COVID-19 infection at the age of 11. However, the patient continued to experience frequent coughing attacks and repeated visits to the emergency department after inhalation of β2-stimulants failed to improve his cough. We admitted him to the allergy center for examinations to assess the BA severity. In the airway hypersensitiveness test, saline inhalation performed prior to methacholine inhalation caused expiratory stridor and respiratory distress in the larynx, which worsened with β2-stimulant inhalation. Based on these results, we ruled out BA and diagnosed ILO. We instructed him on breathing maneuvers, and he was able to respond appropriately when symptoms appeared. We then started reducing his ICS dose.
Keywords: COVID-19; asthma action plan; bronchial asthma; inducible laryngeal obstruction; vocal cord dysfunction.