Symptomless microhaematuria in schoolchildren: causes for variable management strategies

We reviewed published data on the frequency of underlying disorders in schoolchildren with microscopic or gross isolated haematuria (IH), and evaluated management strategies. We found five reports of microscopic IH in screened asymptomatic schoolchildren, three reports of microscopic IH detected by case-finding, and five surveys of kidney biopsies in referred children with microscopic and gross IH. We listed the reported underlying disorders, and estimated the benefit from their early detection and treatment. Most children with microscopic IH, whether detected by screening or case-finding, had no significant underlying disease. Some had disorders that may benefit from early treatment (membranoproliferative glomerulonephritis, obstructive uropathy, urolithiasis), or counselling (hereditary nephropathy, renal cystic disease). The combined prevalence of these five diseases was 0-7.2% in children with microscopic IH detected by screening, and 3.3%-13.6% in those with microscopic IH detected by case-finding. The combined prevalence of membranoproliferative glomerulonephritis and hereditary nephropathy among kidney biopsies was 11.6%-31.6% in children with microscopic IH, and 3.6%-42.1% in children with gross IH. Variable management strategies for schoolchildren with IH result from uncertainty about the frequency of underlying disorders and the efficacy of their early treatment. With no evidence that detecting IH leads to prevention of renal function impairment, screening for IH in symptomless schoolchildren is not warranted. Once detected, however, IH justifies further investigation.