Risk of Renal Scarring in Children With a First Urinary Tract Infection: A Systematic Review

To our knowledge, the risk of renal scarring in children with a urinary tract infection (UTI) has not been systematically studied.To review the prevalence of acute and chronic renal imaging abnormalities in children after an initial UTI.We searched Medline and Embase for English-, French-, and Spanish-language articles using the following terms: "Technetium (99m)Tc dimercaptosuccinic acid (DMSA)," "DMSA," "dimercaptosuccinic," "scintigra*," "pyelonephritis," and "urinary tract infection." We included articles if they reported data on the prevalence of abnormalities on acute-phase (≤15 days) or follow-up (>5 months) DMSA renal scans in children aged 0 to 18 years after an initial UTI. Two evaluators independently reviewed data from each article.Of 1533 articles found by the search strategy, 325 full-text articles were reviewed; 33 studies met all inclusion criteria. Among children with an initial episode of UTI, 57% (95% confidence interval [CI]: 50-64) had changes consistent with acute pyelonephritis on the acute-phase DMSA renal scan and 15% (95% CI: 11-18) had evidence of renal scarring on the follow-up DMSA scan. Children with vesicoureteral reflux (VUR) were significantly more likely to develop pyelonephritis (relative risk [RR]: 1.5 [95% CI: 1.1-1.9]) and renal scarring (RR: 2.6 [95% CI: 1.7-3.9]) compared with children with no VUR. Children with VUR grades III or higher were more likely to develop scarring than children with lower grades of VUR (RR: 2.1 [95% CI: 1.4-3.2]).The pooled prevalence values provided from this study provide a basis for an evidence-based approach to the management of children with this frequently occurring condition.