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

Abstract

BACKGROUND: To our knowledge, the risk of renal scarring in children with a urinary tract infection (UTI) has not been systematically studied. OBJECTIVE: To review the prevalence of acute and chronic renal imaging abnormalities in children after an initial UTI. METHODS: We searched Medline and Embase for English-, French-, and Spanish-language articles using the following terms: “Technetium 99mTc 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. RESULTS: 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]). CONCLUSIONS: 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.