Summary

We describe a case of a 3-year-old girl who was admitted with encephalopathy and a right-sided hemiparesis secondary to acute influenza A. She was up-to-date with the Australian National Immunisation Program (which does not routinely include the seasonal influenza vaccine). After initial treatment with intravenous antimicrobials and acyclovir, a brain and spinal cord MRI demonstrated extensive focal necrotic and haemorrhagic changes in keeping with acute necrotising encephalopathy (ANE). She was started on a course of oseltamivir and intravenous pulse methylprednisolone, followed by an oral weaning regimen of prednisolone. After an intense period of rehabilitation, she has made a remarkable recovery. Genetic testing has since confirmed that this girl has the RANBP2 gene mutation, which leads to increased susceptibility of developing ANE. This case report highlights ANE as a rare but severe complication of influenza, the unfortunate complication of having the RANBP2 mutation and the importance of paediatric influenza vaccination.