Presentation of Acute Megakaryoblastic Leukemia Associated with a GATA ‐1 Mutation Mimicking the Eruption of Transient Myeloproliferative Disorder

Children with trisomy 21 are prone to developing hematologic disorders, including transient myeloproliferative disorder ( TMD ) and acute megakaryoblastic leukemia ( AMKL ). The papulovesicular eruption of TMD provides an important clue to the diagnosis. In contrast, AMKL rarely has associated cutaneous findings. We report the case of a 22‐month‐old child with trisomy 21 who presented with the acute onset of diffusely scattered and crusted papules, plaques, and vesicles. A thorough infectious evaluation was negative and the patient was unresponsive to empiric antibiotic and antiinflammatory therapies. Complete blood count ( CBC ) was notable for mild pancytopenia, with a normal peripheral smear. Two weeks later he was reassessed and found to have a population of blasts on repeat CBC . Subsequent evaluation ultimately led to a diagnosis of AMKL . This is the first reported case of a cutaneous eruption in a young child with Down syndrome and transformed AMKL . When children with trisomy 21 present with the acute onset of crusted papules and vesicles that cannot be accounted for by an infectious etiology, a diagnosis of AMKL should be considered even in the absence of a history of TMD .