The hypereosinophilic syndrome in association with acute lymphoblastic leukemia

Abstract

phenicol toxicity. The white blood cell count returned promptly following cessation of methicillin therapy. Levitt and associates ' described a 14-month-old boy with S. aureus pneumonia and gastroenteritis who developed severe neutropenia four days following onset of methicillin therapy. The bone marrow was consistent with maturational arrest of the granulocytic cells. The shift to the left seen in the bone marrow aspirate in Case 1 is consistent with that seen with other semisynthetic penicillins. This suggests that the neutropenia observed with oxacillin is secondary to a reversible toxic effect on the maturation of the granulocytic series. The possibility that the neutropenia was due to an immune mechanism cannot be excluded, but seems unlikely in view of the rapid rise in the neutrophil count following removal of the antibiotic. Bone marrow toxicity by penicillin-like drugs has been infrequently reported in children. Our observation o f severe neutropenia associated with oxacillin therapy in four children indicates that differential white blood cell counts should be obtained frequently during therapy. High-dose semisynthetic penicillins are now used frequently for long-term treatment of penicillin-resistant staphylococcal infections. Thus, there is a large potential for adverse effects on the bone marrow. In our experience with oxacillin, cessation of therapy resulted in recovery from neutropenia within several days.