Recurrent croup in a young child: look beyond airways disease.

We reported here a boy aged 5 years who presented for the evaluation of recurrent croup since infancy. On chest examination, breath sounds were reduced throughout the right lung field with a shifting of the trachea and cardiac apex to the right side. The chest radiograph showed a small right lung with decreased vascularity, hyperinflated left lung and mediastinum shifted towards the right side. Flexible bronchoscopy revealed tracheomalacia with left bronchomalacia due to external pulsatile compression. In CT angiogram, the right pulmonary artery (PA) was absent with dilated left PA. Echocardiography did not show any features of pulmonary arterial hypertension (PAH). Since the child was growing well, and there was no limitation of activity and evidence of PAH, he was managed conservatively and kept on follow-up. Though unilateral absent PA is a rare condition, it should be suspected in children with unilateral hypoplastic lung.