Transient myeloproliferative disorder with vesiculopustular eruption: Early smear is useful for quick diagnosis.

We report a male infant with Down syndrome who had a transient myeloproliferative disorder associated with skin lesions. He was transferred to a neonatal intensive care unit because of low body weight, fetal edema, disseminated intravascular coagulation, and 10% blast cells in the peripheral blood. On postnatal day (PD) 1, erythema with small papules, vesicles, and pustules appeared on the entire body. A smear preparation from the pustules on PD 2 showed 10% blast cells. A biopsy specimen taken on PD 5 revealed subcorneal pustules containing neutrophils and eosinophils. Genetic analyses detected a somatic mutation (197G>T, Glu295Stop) in exon 2 of GATA-1. On PD 10, the eruptions resolved spontaneously and the population of blast cells in peripheral blood decreased to 1%. The number of blast cells in pustules decreased markedly after three days. Therefore, we recommend that cytologic examination should be performed as early as possible.