Varicella Zoster Virus Encephalitis with Advanced Human Immunodeficiency Virus Disease Diagnosed by Brain Biopsy.

A 40-year-old Japanese man with human immunodeficiency virus presented with disturbance of consciousness 2 years after dropping out. He was emaciated without any zoster skin lesions, and his CD4+ lymphocyte count was 4 cells/μL. Disseminated Mycobacterium avium infection and pneumocystis pneumonia were diagnosed, and a brain biopsy revealed varicella zoster virus (VZV) encephalitis with multiple real-time polymerase chain reaction tests and immunochemistry. Antiretroviral therapy and intravenous acyclovir were administered, and the patient survived with neurological sequelae. VZV encephalitis is rare, particularly among people with acquired immunodeficiency syndrome, but it is a significant disease with a poor prognosis.