Steroid therapy in an infant with human herpesvirus 6 encephalopathy

We describe a 10-month-old girl who developed convulsive status during febrile illness. Human herpesvirus 6 DNA was detected in both the serum and the cerebrospinal fluid by polymerase chain reaction. Interleukin-6 was increased in the serum. The patient improved after a commencement of steroids pulse therapy. This case suggests that proinflammatory cytokines are responsible for the pathogenesis of the encephalopathy.