Most common type of red cell aplasia occurring in previously healthy children 6-36 months old, or possibly older. Etiology is uncertain but related to decreased red blood cell production. It is important to distinguish from the more severe but less common congenital presentation of Diamond-Blackfan anemia. May be associated with recent viral infection. Characterized by normocytic anemia, reticulocytopenia and neutropenia, and otherwise normal physical exam. Usually self-resolving within 1-2 months.