Clinical features of primary human herpesvirus-6 infection in an infant with acute lymphoblastic leukemia.

Purpose: The primary infection with human herpesvirus-6 developed concurrently with diagnosis of acute lymphoblastic leukemia and initiation of intensive chemotherapy for the disease in a 4-month-old girl.

Results: Prolonged viremia persisted for 7 days in the presence of neutralizing antibodies, and clinical features such as prolonged febrile and diarrheal period, no appearance of skin rash, and marked bulging fontanelle for 7 days in the absence of the virus DNA in spinal fluid may suggest an atypical clinical course of exanthem subitum and an unusual viral replication in immunocompromised condition.