Transient myeloproliferative disorder (TMD) is a hematologic abnormality usually associated with Down syndrome that may present with a skin eruption in addition to typical systemic findings. We report a case of a patient with TMD and a vesiculopustular eruption without the phenotypic characteristics of Down syndrome who was found to have mosaic trisomy 21. Mutations of the globin transcription factor 1 gene, GATA1, are associated with both TMD and acute megakaryocytic leukemia. Transient myeloproliferative disorder typically presents with pancytopenia, hepatosplenomegaly, and immature circulating white blood cells, and affects approximately 10% of neonates with Down syndrome. These abnormalities rapidly regress within the first few months of life. However, 20% to 30% of neonates with Down syndrome and TMD later develop leukemia. The tumor antigen PRAME (preferentially expressed antigen in melanoma) may serve as a marker for leukemic transformation. We report an illustrative case to alert clinicians about this uncommon cause of vesiculopustular eruption in a neonate without the phenotypic characteristics of Down syndrome and review the clinical findings and laboratory studies that aid in accurate diagnosis.