Successful High-Dosage Dexamethasone Treatment of H1N1 Influenza A Pneumonia Complicated with Acute Necrotizing Encephalitis in an HIV-Infected Adult

Neurological manifestations in H1N1 influenza A infection are very rare, especially in adults, and its mechanism of action is still uncertain. Here, we reported the case of a 53-year-old woman with human immunodeficiency virus infection (HIV) who had H1N1 influenza A pneumonia complicated with very rare acute necrotizing encephalitis, although the HIV was under control. With prompt identification and administration of high dosage of dexamethasone, her mental status improved from stupor to clear, with minimal right hemiparesis. Further, brain magnetic resonance image revealed great resolution of mass effect. This dramatic improvement in response to the treatment may improve our understanding of the pathophysiology between H1N1 influenza A infection and acute necrotizing encephalitis.