Respiratory Syncytial Virus Infection Triggering a Pulmonary Hypertensive Crisis in a Boy With Prader-Willi Syndrome-Associated Sleep-Disordered Breathing.

Prader-Willi syndrome (PWS) is a multisystem genetic disorder frequently complicated by sleep-disordered breathing, including obstructive sleep apnea. Respiratory infections may precipitate acute decompensation in vulnerable patients with PWS. A four-year-old boy with genetically confirmed PWS receiving growth hormone therapy developed respiratory distress and cyanosis. He was found to be respiratory syncytial virus-positive and presented with acute respiratory acidosis and markedly elevated aminotransferases with coagulopathy. Echocardiography showed right-sided cardiac dilation consistent with pulmonary hypertension. He was managed with noninvasive ventilation, oxygen supplementation, and diuretics, followed by step-down to nasal continuous positive airway pressure. Liver enzymes normalized as his respiratory status improved. Polysomnography after stabilization showed obstructive sleep apnea with considerable nocturnal desaturation, and home continuous positive airway pressure was initiated. Respiratory syncytial virus (RSV) infection can trigger acute-on-chronic respiratory failure and cardiopulmonary decompensation in children with PWS and unrecognized severe nocturnal hypoxemia. Early screening and ongoing surveillance for sleep-disordered breathing, cardiopulmonary complications, and careful management during intercurrent infections are essential. RSV immunoprophylaxis, such as palivizumab, may warrant individualized consideration in high-risk young children with PWS who have impaired airway clearance or considerable respiratory comorbidity.