Influenza A-Triggered Severe Acute Chest Syndrome in a Child With Sickle Cell Disease Complicated by Plastic Bronchitis and Posterior Reversible Encephalopathy Syndrome.

Acute chest syndrome (ACS) is one of the leading causes of morbidity and mortality in children with sickle cell disease (SCD) and is commonly precipitated by respiratory infections. Among viral triggers, influenza A is a recognized cause of severe ACS and may contribute to rapid clinical deterioration. We report a case of a nine-year-old girl with homozygous sickle cell disease (HbSS), with irregular follow-up and poor adherence to hydroxyurea therapy, who presented with severe influenza A-associated ACS. Her course was complicated by plastic bronchitis, posterior reversible encephalopathy syndrome (PRES), and markedly elevated transcranial Doppler velocities. She required admission to the pediatric intensive care unit, bronchoscopy with removal of bronchial casts, transfusion therapy, and coordinated multidisciplinary management. The case illustrates a severe and unusual constellation of pulmonary and neurological complications occurring in the setting of poorly controlled SCD. This case highlights the potential for influenza A to precipitate life-threatening ACS in children with SCD, particularly in the context of suboptimal disease control. It also underscores the complex interplay between pulmonary and neurological complications and emphasizes the importance of early recognition, timely escalation of care, and multidisciplinary management in severe presentations.