Parvovirus B19 Infection Mimicking Juvenile Myelomonocytic Leukemia in an Immunocompetent Child.

Most of the parvovirus infections in humans are benign. Clinical manifestations of parvovirus B19 infections in children vary from erythema infectiosum in healthy children to aplastic crisis in patients with hematological disorders (such as sickle cell disease) and immunocompromised patients. Parvovirus B19 infects the erythroid progenitor cell in the bone marrow and causes transient erythroblastopenia. Transient leukoerythroblastic reaction is a rare presentation of parvovirus infection. Our case is a child presenting with fever of unknown origin (FUO) who was investigated and treated in different hospitals for FUO. He was investigated for infections, rheumatological causes, and malignancies. Clinical manifestations and bone marrow findings were mimicking juvenile myelomonocytic leukemia (JMML) but eventually diagnosed to have a parvovirus B19 infection, which resolved spontaneously in due course.