Vesicoureteric reflux — Rapid | Doctor’s Passport

Synopsis

Explain reflux as a developmental ureterovesical-junction problem, distinguish it from acute infection, identify children at risk of renal injury, and use selective surveillance, prophylaxis and surgery rather than reflexive intervention.

Vesicoureteric reflux is retrograde movement of urine from bladder into one or both ureters, sometimes reaching the kidney because the ureterovesical junction does not close effectively.
Primary VUR is congenital and often improves as the intramural ureter lengthens with growth. Secondary VUR results from high bladder pressure or outlet dysfunction.
VUR causes no distinctive symptom by itself; it is usually discovered after antenatal urinary dilatation, febrile UTI or selective MCUG.
Reflux is graded I–V on MCUG. Grade describes anatomical extent and dilatation, but management also depends on age, infection recurrence, renal damage and bladder-bowel function.
First-line assessment is UTI history, culture results, voiding pattern, constipation, growth, blood pressure, urinalysis and renal function when disease is bilateral or scars are suspected.
Ultrasound assesses kidney growth, parenchyma, ureters and bladder but cannot reliably exclude reflux. MCUG is the reference anatomical test when NICE-defined indications exist.
Do not use MCUG routinely after every UTI. NICE restricts it by age, recurrence, atypical features, ultrasound dilatation, poor flow, non-E. coli infection and family history.
First-line management is prompt treatment of UTI, normal fluids and timed voiding, plus active treatment of constipation and dysfunctional elimination.
Do not prescribe prophylaxis simply because one uncomplicated UTI occurred. For recurrent UTI or selected high-grade VUR, consider a daily low-dose antibiotic only with specialist advice.
When prophylaxis is used, select from current NICE age and weight tables using prior susceptibilities and renal function, review benefit and resistance at least every 6 months, and keep rapid access for breakthrough cultures.
Surgery is not routine. Urological options are considered for recurrent febrile infections despite optimised conservative care, significant high-grade reflux, worsening renal risk or selected anatomical problems.
Long-term follow-up is proportional: normal imaging and no recurrence may need none, whereas bilateral defects, hypertension, proteinuria or impaired function require renal surveillance.

Key red flags

A baby under 3 months with fever or suspected UTI requires urgent paediatric assessment regardless of known reflux grade.

Sepsis, anuria, poor urine flow, palpable bladder, raised creatinine or marked bilateral hydronephrosis requires urgent investigation for infected obstruction.

Recurrent febrile UTI despite appropriate prophylaxis raises concern for resistance, non-adherence, bladder dysfunction or an anatomy needing surgical review.

Hypertension, persistent proteinuria, impaired eGFR, poor growth or bilateral renal defects indicates clinically important reflux nephropathy and nephrology follow-up.

Bilateral impalpable testes, proximal hypospadias or other atypical genital development with urinary abnormality may indicate a broader congenital or endocrine diagnosis.

A weak stream in a boy suggests posterior urethral valves or outlet dysfunction, not uncomplicated primary reflux alone.

Investigation priorities

First-line: renal and bladder ultrasoundFirst stepFirst line

Assess kidney size and parenchyma, hydronephrosis, ureters, bladder and post-void residual.

Management branches

DiagnosisConfirm clinically relevant reflux

Imaging or recurrent infection raises suspicion of VUR.

Verify UTI history and review ultrasound, bladder emptying, constipation and urinary stream.
Use MCUG only when the NICE age and phenotype criteria justify invasive reflux imaging.
Grade reflux and integrate DMSA, kidney growth, function and infection burden in a paediatric urology or nephrology plan.

ConservativeProtect against infection

Renal function is stable and immediate surgery is not indicated.

Provide rapid-access urine sampling and prompt culture-directed treatment for fever or urinary symptoms.
Normalise fluids, timed voiding and complete emptying, and treat constipation or dysfunctional elimination actively.
Use ultrasound, blood pressure, proteinuria and renal-function surveillance at intervals set by grade and parenchymal risk.

Key medicines

Trimethoprim prophylaxisWith specialist advice from age 3 months: 2 mg/kg orally at night, maximum 100 mg per dose; NICE also gives age-banded alternatives. Review the trial at least every 6 months and use a different antibiotic for acute UTI.Check culture susceptibility, renal function, blood count when prolonged treatment warrants it, folate-antagonist interactions and pregnancy possibility in adolescents; resistance and uncertain benefit must be discussed.

Nitrofurantoin prophylaxisWith specialist advice and eGFR at least 45 mL/minute: age 3 months to 11 years, 1 mg/kg orally at night; age 12 to 15 years, 50 to 100 mg at night, reviewed at least every 6 months.Do not use for acute pyelonephritis. Avoid when renal function is insufficient and monitor for pulmonary, hepatic, neurological or haemolytic toxicity during prolonged exposure; follow MHRA and BNFC advice.

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