Urinary tract infections under 24 months old: Is it possible to predict the risk of renal scarring?

Background: Urinary tract infection is one of the most common bacterial infections in the first two years of life and it can lead to irreversible renal scarring. Renal scintigraphy is the gold standard method for detection of renal scars. The aim of our work was to revise the cases of pyelonephritis, detect the possible predictors for renal scarring and compare those results we would have obtained if we had followed current NICE guidelines. Methods: Retrospective analysis of all patients aged under 24 months evaluated in the paediatric department and diag- nosed with pyelonephritis during a three -year period. We excluded the cases in which no renal scintigraphy was performed. Results: Of the 59 children analysed, 50.8% were boys and 86.4% were under one -year old. Escherichia coli was the predominant bacteria. Renal ultrasonography showed abnormal findings in 23 patients (39%). The incidence of renal scarring was 15.3%. Age, atypical urinary tract infection and abnormal renal ultrasonography seem to be correlated with risk of renal scarring, although the results were not statistically significant. C -reactive protein level is significantly correlated with renal scarring risk (p=0.047). Working outside the NICE guidelines allowed us to catch 7 further renal scars. Conclusions: It’s arguable if renal scintigraphy must be performed in all cases of pyelonephritis diagnosed in the first 24 months of life or only when there are other risk factors for renal scarring. Age, atypical urinary tract infection, C -reactive protein level and renal ultrasonography results must be taken into account in the decision to perform renal scintigraphy in a child. More prospective studies with larger cohorts are needed.