Metabolic disturbance as a cause of recurrent hematuria in children.

Metabolic disturbance as a cause of recurrent hematuria in children. To evaluate metabolic disturbance as a cause of hematuria, 250 children, aged eight months to fourteen years, with recurrent hematuria were studied. In the present series, metabolic disturbance was mainly due to idiopathic hypercalciuria (IH), the most common etiology of hematuria without proteinuria in childhood. Sixty-seven (27%) of the children had IH, ten children (4%) had hyperuricosuria, and 27 (11%) had nephrolithiasis. To better characterize the IH into renal (RH) or absorptive hypercalciuria (AH) subtypes, 45 of the 67 children (ranging age from six to twelve years) were further submitted to an oral calcium load test. Eighteen patients (40%) had AH, 7 (15.5%) RH and 20 (44.4%) could not be classified as having AH or RH [indeterminant (ID) idiopathic hypercalciuria group]. Intravenous pyelography or ultrasound were normal in all children. The oral calcium load test may be useful in characterizing the subtype of IH in some children; however, a great number of the IH children were characterized as indeterminant. Also hyperuricosuria, recently described as another metabolic disturbance associated with hematuria, may be an important cause of recurrent hematuria in children.