Reassessment of the microcytic anemia of lead poisoning

Hematologic abnormalities in childhood lead poisoning may be due, in part, to the presence of other disorders, such as iron deficiency or thalassemia minor. In order to reassess increased lead burden as a cause of microcytic anemia, we studied 58 children with class III or IV lead poisoning, normal iron stores, and no inherited hemoglobinopathy. Anemia occurred in 12% and microcytosis in 21% of these children. The combination of anemia and microcytosis was found in only one of 58 patients (2%). When only children with class IV lead poisoning were studied, the occurrence of microcytosis increased to 46%. However, the combination of microcytosis and anemia was found in only one of these 13 more severely affected patients. Microcytic anemia was similarly uncommon in children with either blood lead concentration greater than or equal to 50 microgram/100 ml. These data indicate that microcytosis and anemia occur much less commonly than previously reported in childhood lead poisoning uncomplicated by other hematologic disorders.