[Diagnostic significance of hematuria in pediatrics].

Hematuria is the presence of more than 5 RBC's in repeated urinary sediments. Erythrocyturia may be present as an isolated finding or it may be associated to other clinical findings that may lead to the etiology of the hematuria. Its origin may be renal or extrarenal. In the neonate, meatal or urethral bleeding, polycystic kidney or hydronephrosis must be considered. In the infant, hematuria may be due to vascular disease, renal vein thrombosis, as well as to urinary tract infection, urinary tract obstruction or acute tubular interstitial nephritis due to drug ingestion. Primary and secondary glomerulopathies, urinary tract infection and urolithiasis are the most frequent causes of hematuria in pre-school or school-age children. The diagnostic approach emphasizes the importance of the clinical history, familial background and the circumstances of presentation. RBC casts and proteinuria may suggest the presence of a glomerulopathy. Leukocyturia is more frequent in urinary tract infections and requires urine cultures and intravenous pyelogram. In cases of isolated hematuria, blood clotting test, P. T., P.T.T., platelet count and RBC's morphology may be required to rule out hematological disorders. The intravenous pyelogram, voiding cystogram, and occasionally cystoscopy will help to rule out urological abnormalities. If the previous results were negative, the renal biopsy will help to distinguish IgA mesangiopathy, Alport's syndrome or essential hematuria; this last diagnosis resulting by exclusion.