Idiopathic subglottic stenosis and the consequences in cardiopulmonary exercise testing.

A 15-year-old male patient with progressive dyspnoea and exercise-related wheezing was analysed with spirometry, ECG and a cardiopulmonary exercise test with blood gas analysis. Earlier analysis by a paediatrician concluded no abnormalities. However, the previously performed spirometry test may have clarified the diagnosis in an earlier stage.Severe hypoventilation was seen during the exercise test with hypercapnia and hypoxaemia while hearing a stridor during exercise. Eventually, a circular subglottic stenosis was seen on a CT scan of the chest. No malignancy or granulomatosis with polyangiitis was seen in biopsy and pathologic examination. There was no history of trauma, intubation or infection. Therefore, the diagnosis idiopathic subglottic stenosis was established. Bronchoscopic balloon dilation followed several times, leading to full recovery.