CASE FOR DIAGNOSIS Stridor in an infant

A 7 month old male presented with stridor from the age of 6 weeks. He was one of identical twins born at 38 weeks gestation following an otherwise uncomplicated pregnancy and delivery. He remained completely well until 6 weeks of age when the isolated symptom of stridor began gradually, increased in loudness until 10 weeks of age and then remained constant until presentation. It was present at all times, worse on exertion and not influenced by body position nor feeding. The child had remained well throughout and was thriving with no episodes of fever, feed refusal nor swallowing difficulties. There was no history of ingested nor inhaled foreign body. A clinical diagnosis of laryngomalacia had been made by several medical practitioners. On examination he was well looking with normal growth. He had biphasic stridor that was louder on expiration, rough in character and associated with mild indrawing of intercostal muscles. The chest was normally shaped and clear to auscultation. Examination was otherwise normal. The unusual character of stridor and age of onset of symptoms prompted further investigation. His chest radiograph was normal with no apparent airway narrowing. Barium swallow showed no obvious abnormality but was limited owing to technical difficulties. Flexible fibreoptic bronchoscopy was performed. This was followed by spiral computed tomography (CT) of the chest, (fig. 1) and a bronchogram (fig. 2).