The Incidence of Renal Scarring and its Related Factors in Children with First Pyelonephritis

Urinary tract infection (UTI) is common in children. UTIs are important in view of the morbidity and risk of scarring. Several factors have been reported to be responsible for progression to scarring. The aim of this study was to determine the incidence of scar and its related factors. In this study, 26 males and 77 females (3 months - 12 years) with first pyelonephritis were evaluated. All patients underwent ultrasound, cystourethrography, and Dimercaptosuccinic acid scan. A follow-up scan was performed 6 months later. Age, gender, organism, presence, and grade of vesicoureteral reflux (VUR), delay in treatment, total white blood cell counts (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels on admission were recorded. Logistic regression analysis was used to evaluate the association between the variables and scar. Of 103 patients, 47.6% had VUR. Scar was detected in 38.8%. There were significant associations between delay in treatment (p=0.0001), grade of VUR (p=0.03) and elevated ESR (p= 0.006), CRP (p=0.002) and WBC (p=o.oo5) with scar. No association was established with age, sex, VUR, and organism. On multivariate analysis, delay in treatment was independently associated with scar. We found that the grade of VUR, delay in treatment, and increased ESR, CRP and WBC were important factors related to scar.