Pre-eruptive varicella encephalitis and cerebellar ataxia

Varicella-related neurologic symptoms usually appear during or following the exanthem. Pre-eruptive neurologic manifestations are extremely rare. We report a 6-year-old boy who developed encephalitis, characterized by drowsiness and left-sided hyperactive deep tendon reflexes and cerebellar ataxia, both of which antedated the exanthem by 16 days. The diagnostic and public health implications are discussed.