The clinical significance of asymptomatic gross and microscopic hematuria in children.

BACKGROUND The development of asymptomatic gross or microscopic hematuria is relatively common in children. OBJECTIVE To evaluate the clinical importance of hematuria in children and the necessity for such an evaluation using a defined diagnostic protocol. DESIGN The protocol included a personal and family history, physical examination and blood pressure determination, and a set of comprehensive laboratory and radiological examinations. RESULTS Of 342 children with microscopic hematuria, no cause was uncovered in 274 patients. The most common cause discovered was hypercalciuria (16%), followed by post-streptococcal glomerulonephritis (1%). Of 228 children with gross hematuria, no cause was uncovered in 86 patients. The most common cause discovered was hypercalciuria (22%). Ten patients had clinically important structural abnormalities. Fifty-three patients qualified for renal biopsy; 36 had IgA nephropathy. CONCLUSIONS Our results suggest that diagnostic evaluation for potential causes of asymptomatic microscopic hematuria in children may not be necessary. Because microscopic hematuria can, rarely, be the first sign of occult renal disease, long-term follow-up is mandatory. As clinically important abnormalities of the urinary tract are commonly discovered in children with asymptomatic gross hematuria, a thorough diagnostic evaluation is warranted.