It’s relatively common to discover that children sometimes have blood in their urine, either visible to the unaided eye or under a microscope. Nonetheless, kids with this condition (hematuria) require close attention, researchers report, although microscopic hematuria appears to be of lesser concern.

As Dr. Jerry Bergstein told AMN Health, “Our research shows that in otherwise healthy children, blood detected by microscopic examination of the urine in the absence of protein in the urine or high blood pressure does not require a diagnostic evaluation because clinically important disease is rarely detected.”

However, “long-term follow-up is mandatory.”

On the other hand, he added, “Blood in the urine that is visible to the naked eye warrants a thorough diagnostic evaluation because clinically important abnormalities are commonly discovered.”

Bergstein and colleagues at Indiana University School of Medicine, Indianapolis, studied 342 children with microscopic hematuria. No cause was found in 274 of these children. When a cause was found, it was most often due to high calcium levels or kidney damage from a strep infection, Bergstein’s group reports in the Archives of Pediatrics and Adolescent Medicine.

In another 228 children with obvious blood in the urine, no cause was established in 86 subjects. The most common cause again was high calcium levels, but ten patients “had clinically important structural abnormalities,” the researchers report. Another 53 underwent biopsy for suspected kidney disease.

SOURCE: Archives of Pediatrics and Adolescent Medicine, April 2005.