Influenza B-associated acute necrotising encephalopathy of childhood treated with tocilizumab

The objective of the study is to describe the clinical presentation, investigations and management of a child with severe ANEC treated with tocilizumab in combination with methylprednisolone (MTP) and intravenous immunoglobulins (IVIG) with good outcome. Review of case notes and literature was done. A 10-year-old previously fit and well girl presented with fever, vomiting, loose stools with severe dehydration and shock. She had one episode of generalised-tonic-clonic-seizure, following which she had a reduced level of consciousness. She was invasively ventilated and received paediatric intensive care unit care. Neuroprotection given until day 3. Levetiracetam, oseltamivir, antibiotics and vitamins were started. Magnetic resonance imaging brain revealed a trilaminar pattern of diffusion-restriction in bilateral thalami on apparent diffusion coefficient (ADC) images and T2 and fluid-attenuated inversion recovery hyperintense areas in the brainstem, bilateral cerebellar hemisphere and thalami with diffusion-restriction suggestive of ANEC. Cerebrospinal fluid (CSF) analysis showed elevated protein, normal glucose, and no cells; the herpes simplex virus-polymerase chain reaction was negative. Electroencephalogram showed abnormal background with slowing, suggesting encephalopathy with no epileptiform activity. ANEC severity score was 8/9 (shock-3, brainstem lesions-2, age-2, CSF Protein-300 mg/dL-1). Hence, she was given MTP 30 mg/kg, a single dose of tocilizumab 800 mg and IVIG at 2 g/kg. The serum interleukin-6 level was elevated. Flu-panel showed influenza B. She was extubated on day 12. She was discharged home on day 19 and made a neurological recovery with supportive therapies and steroids. At present, a year later, the child is well except for mild squint and mild coordination difficulty and is attending mainstream school.