Polycythemia vera as a cause of systemic hypertension.

An underlying medical condition as a cause for elevated blood pressure is suspected when hypertension occurs in younger children or those with markedly high readings (hypertensive urgency or emergency). We highlight a unique presentation and underlying medical condition, polycythemia vera (PV), as the cause of secondary hypertension in an asymptomatic 5-year-old child presenting for a routine physical examination and found to have hypertensive urgency. Laboratory evaluations revealed leukocytosis, polycythemia, thrombocytosis, and low erythropoietin level. JAK2-V617F mutational analysis confirmed the diagnosis of PV. She was managed with antihypertensive medications, therapeutic phlebotomy, and cytoreductive therapy with notable improvement in hypertension over time. She continues regular follow-up with nephrology and hematology/oncology. She has not had any further serious complications or evolution of her PV. This case demonstrates the importance of a broad differential diagnosis in the setting of very early onset hypertension, including myeloproliferative disorders.