Simultaneous acute splenic sequestration and transient aplastic crisis in children with sickle cell disease.

Acute splenic sequestration crisis (ASSC) is a hematological emergency in young children with sickle cell disease (SCD), characterized by worsening anemia and splenomegaly, usually with reticulocytosis and thrombocytopenia. Transient aplastic crisis (TAC) due to parvovirus B19 infection occurs in older children with SCD, and typically manifests as worsening anemia with reticulocytopenia and no splenomegaly. Five older children with SCD (4 HbSC, 1 HbSS on hydroxyurea) developed ASSC concurrent with TAC and had a severe clinical course. Our cases suggest that older children with SCD and acute parvovirus infection should be monitored closely for splenomegaly and multi-system dysfunction.