Varicella zoster virus (VZV) has been increasingly linked with encephalitis and atypical presentations in immunosuppressed patients. We present a patient with history of immunosuppressant intake for polymyositis who initially presented with throbbing frontal headache that raised the suspicion of migraine. She did not respond to anti-migraine medication and later developed stimulus induced myoclonus. She then had significant neurological decline and eventually became encephalopathic. Her initial imaging of brain was unremarkable which warranted further investigations. She was then diagnosed to be VZV positive in the cerebrospinal fluid (CSF) sample that confirmed VZV encephalitis. She responded well to IV Acyclovir treatment and her neurological function improved significantly. In this case, there was delay in diagnosis of VZV in the setting of immunosuppression and non-specific clinical presentation. Therefore, we encourage to strongly consider early VZV diagnostic work up and treatment in immunocompromised patients who can present with non-specific symptoms without a typical cutaneous rash.
Keywords: Encephalitis; Immunocompromised; Polymyositis; VZV.