Pediatric UTI occurs in 7% of children less than 2 years of age presenting with a fever.^1-3 The most concerning long-term consequence of febrile UTI is renal scarring, which may increase the risk of hypertension and chronic kidney disease. At the time of presentation, prompt diagnosis and antibiotic initiation can decrease the risk of renal scarring.^4-6 Another risk factor for renal scarring is urinary organism other than Escherichia coli.^7-9 Although there are individuals who may be genetically predisposed to renal scarring, there are currently no tests available for this purpose.^10-13 Young age at time of febrile infection is no longer thought to be a risk factor for renal scarring.^7,14,15

Since few of the aforementioned risk factors are modifiable, long-term management of initial febrile UTI centers around preventing recurrent infections. There is strong evidence that the risk of renal scarring increases with each febrile UTI.^14,16-18 A post hoc analysis of data from 2 multicenter prospective studies (RIVUR and CUTIE) reported a nearly 12-fold increase in the odds of renal scarring following the second febrile UTI (2.8% after the first episode vs 25.7% after the second episode; odds ratio 11.8, 95% CI 4.1-34.4).¹⁸

In addition to bowel-bladder dysfunction, vesicoureteral reflux (VUR) is a known risk factor for recurrent UTIs. Data from the 2 multicenter prospective studies demonstrated 2-year recurrence rates of 25.4% and 17.3% for children with and without VUR, respectively. Of note, children with bowel-bladder dysfunction in addition to VUR are at the highest risk of recurrence, with a 2-year recurrence rate of 56%.¹⁹ Another modifiable risk factor that can reduce recurrent infection is circumcision for uncircumcised boys under 1 year of age.²⁰ Once VUR is diagnosed, prophylactic antibiotics or antireflux surgery may be considered to reduce UTI risk.^21-23

The dilemma for providers evaluating a child following a first-time febrile UTI is whether or not to obtain a voiding cystourethrogram (VCUG). VCUG can help identify VUR and other congenital anomalies of the urinary tract that may increase the risk for recurrent UTI and renal scarring. The 2011 American Academy of Pediatrics UTI guideline, which was retired in 2022, recommends against performing routine VCUG in children less than 2 years of age presenting with a first-time febrile UTI and normal renal bladder ultrasound.^17,24

VCUG utilization and VUR diagnosis have decreased significantly following the 2011 American Academy of Pediatrics UTI guidelines.^25-28 A potential consequence of this change in practice pattern is a longer period in which children with underlying VUR go undiagnosed. This may lead to missed opportunities to decrease the risk of recurrent infection and renal scarring through treatment of VUR, as well as aggressive management of bowel and bladder dysfunction.^25,29

However, blindly obtaining VCUGs for all children presenting with a febrile UTI is not the solution. Nonselective utilization of VCUGs will exacerbate the problem of overdiagnosis and overtreatment of VUR, unnecessary instrumentation and radiation exposure for children without anatomic genitourinary anomalies, and tremendous expenditure of valuable health care resources.

Instead, necessity of VCUG following a febrile UTI should be based on a multitude of factors that may alter a child’s risk of recurrent UTI and renal scarring. For example, girls are at significantly higher risk for UTI compared to boys, except in early infancy. Uncircumcised boys are at higher risk for UTI compared to circumcised boys during infancy. Underlying constipation, voiding dysfunction, and bowel and bladder dysfunction increase the risk of recurrent infection, so it may be particularly important to identify additional modifiable risk factors such as VUR in this population. A child’s comorbidities and family history (particularly family members with VUR and renal scarring) should also be considered during this process; non-E coli urinary pathogen and complex clinical course are 2 factors that should prompt a VCUG following the initial febrile UTI.

Risk stratification of a child’s risk for recurrent infection and renal scar formation following a first-time febrile UTI is not straightforward. Calculation of risk is not an additive process, and risk changes over time in our growing patients. There have been efforts to simplify this process using risk calculators.^27,28 However, limitations in data granularity, heterogeneity in outcome measures, and lack of high-volume data are major barriers for developing an accurate and generalizable model that will enable a targeted workup for VUR.

So, should we be ordering more VCUGs to prevent kidney damage after UTI? Yes, but in a selective fashion, targeting the patients who stand to benefit the most from it.