Onset of pallor in children between 1 month and 7 years of age, normochromic- normocytic anemia, absence of reticulocyte response, marrow red cell aplasia with preservation of other hematopoietic lines, and spontaneous recovery usually within one month without recurrence. It was first described by Gasser in 1949, who reported 12 children in whom erythroblastopenia followed toxic, allergic, or infectious episodes. White cell counts are normal.
Platelet counts are usually normal or slightly elevated when in the recovery phase.
Bone marrow examination shows substantial erythroblastopenia in most patients, often with maturation arrests. The major disease which must be differentiated from TEC is the Diamond- Blackfan anemia. First, in TEC the patients often have a previous history of a normal blood count. If the history and age are insufficient for distinguishing between TEC and Diamond- Blackfan anemia, other lab studies may be helpful. Wang and Mentzer pointed out in 1976 that evaluation of erythrocyte characteristics may allow a definitive diagnosis even where clinical findings are ambiguous.