Vesiculopustular eruptions in Down syndrome neonates with myeloproliferative disorders.

BACKGROUND Infants with Down syndrome are at increased risk for hematologic abnormalities, including leukemoid reaction, transient myeloproliferative disorder, and congenital leukemia. The differential diagnosis of a vesiculopustular eruption in an infant with Down syndrome and these hematologic abnormalities is broad and includes benign, self-limited disorders as well as life-threatening infections. OBSERVATION We describe 3 newborns with Down syndrome and vesiculopustular eruptions associated with myeloproliferative disorders during the neonatal period. These lesions differ from other neonatal vesicular eruptions in that they have a unique distribution, display pathergy, and contain immature hematopoietic cells similar to circulating blast cells. Resolution occurs without treatment as the hematologic disorder subsides. CONCLUSIONS Infants with Down syndrome and hematologic abnormalities may have a cutaneous eruption that has characteristic clinical and histopathologic findings. It is possible that this eruption has been unrecognized in the past because of its self-limited course. Whether this eruption is a prognostic factor for the subsequent development of leukemia is uncertain.