The aim of this study was to determine the association between previously documented risk factors such as recurrent pyelonephritis with the incidence of renal scarring after acute pyelonephritis in children.

Children with acute pyelonephritis who were admitted to the Department of Pediatrics of a teaching hospital during 2007–2009 were enrolled in this study. DMSA scans were obtained 4–6 months after the last episode of pyelonephritis in all patients.

A total of 80 children with acute pyelonephritis were enrolled in this study. Most of them were girls (77.5%), with a median age of 12 months. Nearly half of the children (n=44; 55%) had one or more renal scars. The distribution of gender, CRP level and leukocytosis did not differ significantly regardingthe absence or presence of renal scars (p>0.05). Most of the scars occurred in children who had presented with bilateral pyelonephritis (69.4% vs. 18.2%, p=0.001). Most of the patients with renal scars had a positive history of vesicoureteral reflux (VUR) (75% vs.13.6%, p=0.001). The significant roles of recurrent pyelonephritis and presence of VUR were further confirmed by multivariate analysis.

According to our findings, presence of VUR and recurrent pyelonephritis are independently associated with a higher incidence of renal scarring.