Hyponatremic Hypertensive Syndrome Presenting as Malignant Hypertension in a Four-Year-Old Girl

The prevalence of renal and renovascular hypertension in the general population is not known precisely; in children it probably accounts for the majority of cases of secondary hypertension. The symptoms of renovascular hypertension vary, and sometimes it can be asymptomatic. In rare cases, clinical manifestations can include electrolyte disorders including hyponatremia. An uncommon etiology of true hyponatremia of renal origin is the hyponatremic hypertensive syndrome. It has been reported in adults with malignant hypertension, but was considered as an unusual form of presentation of renovascular disease in children. In this report, a four-year-old girl presented with hypertensive encephalopathy related to the hyponatremic hypertensive syndrome caused by right renal artery stenosis. Treatment with percutaneous angioplasty was successful, with total resolution of symptoms. This case emphasizes the importance of routine blood pressure evaluation as a major contribution to the prevention of morbidity and mortality associated with severe forms of hypertension in children.