Urinary tract infections in children

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Last reviewed: 12 Aug 2025

Last updated: 05 Jun 2025

Urinary tract infections (UTIs) are common in children. Symptoms and signs may be nonspecific, particularly in neonates and infants. Older children may have dysuria, urgency, or frequency with a lower urinary tract infection, or fever, loin or back pain, and vomiting with upper UTI (pyelonephritis).

An appropriately obtained urine specimen can confirm the diagnosis and pathogen; urine culture and antimicrobial susceptibility testing will define the appropriate antibiotic for treatment.

Anatomic and functional abnormalities of the urinary tract and bowel may predispose children to recurrent UTIs. Further evaluation of children with recurrent UTIs is required to identify any treatable underlying cause. Recurrent UTIs may lead to renal scarring and renal insufficiency.

Definition

Pediatric urinary tract infection (UTI) is an illness caused by infection of the lower urinary tract (cystitis), the upper urinary tract (pyelonephritis), or both. The presence of pyuria and symptoms distinguishes UTI from asymptomatic bacteriuria.[1]

Asymptomatic bacteriuria is the presence of bacteria in urine obtained in asymptomatic children on routine screening or incidentally during other investigations. The prevalence of asymptomatic bacteriuria is 0.37% in boys and 0.47% in girls, with highest rates in uncircumcised boys younger than 1 year old and girls older than 2 years of age.[2] Asymptomatic bacteriuria does not require treatment.[3]

Uncomplicated UTI occurs in a child who has a structurally and functionally normal urinary tract, normal renal function, and a competent immune system. Complicated UTI occurs in a child who has a structural or functional abnormality of the urinary tract.[1]

History and exam

Key diagnostic factors

fever >102.2°F (>39°C)
irritability (neonates and infants)
poor feeding (neonates and infants)
suprapubic tenderness
costovertebral angle tenderness

Full details

Other diagnostic factors

foul-smelling urine (infants, older children, and adolescents)
dysuria (preschool age, older children, and adolescents)
urinary frequency (older children and adolescents)
abdominal/flank pain (infants, older children, and adolescents)
vomiting
ill appearance (neonates)
gross hematuria (older children and adolescents)
new-onset urinary incontinence (toddlers, older children, and adolescents)

Full details

Risk factors

age <1 year
female sex
uncircumcised boys in the first year of life
previous UTI
bladder and bowel dysfunction
vesicoureteral reflux
sexual activity
no history of breastfeeding
anatomic abnormalities or previous surgery to the urinary tract
immunosuppression
protein-energy malnutrition

Full details

Diagnostic investigations

1st investigations to order

urine dipstick
urine microscopy
urine culture

Full details

Investigations to consider

urine flow cytometry
blood culture
complete blood count
inflammatory markers
fungus urine culture
serum creatinine, BUN and electrolytes
renal and/or bladder ultrasound
dimercaptosuccinic acid (DMSA) scan
voiding cystourethrogram (VCUG)

Full details

Treatment algorithm

INITIAL

vesicoureteral reflux: no history of febrile UTIs

ACUTE

age ≤2 months

age >2 months

ONGOING

recurrent UTIs

Contributors

Authors

Joana Dos Santos, MD, MHSc, FRCPC

Assistant Professor of Pediatrics

Medical Pediatric Urologist

The Hospital for Sick Children

Toronto

Ontario

Canada

Disclosures

JDS declares that she has no competing interests.

Acknowledgements

Dr Joana Dos Santos would like to gratefully acknowledge Dr Beatrice Goilav, Dr Frederick Kaskel, Dr Mary Anne Jackson, and Dr Rene VanDeVoorde, previous contributors to this topic.

Disclosures

BG, FK, MAJ, and RV declare that they have no competing interests.

Peer reviewers

Martin Koyle, MD, MSc, FAAP, FACS, FRCS(Eng), FRCSC

Professor

Department of Surgery and Institute of Health Policy, Management and Evaluation

Staff Pediatric Urologist

The Hospital for Sick Children

Toronto

Ontario

Canada

Disclosures

MK declares that he has no competing interests.

Daniel T. Keefe, MD, FRCSC

Pediatric Urology Fellow

The Hospital for Sick Children

Toronto

Ontario

Canada

Disclosures

DTK declares that he has no competing interests.

Peer reviewer acknowledgements

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Disclosures

Peer reviewer affiliations and disclosures pertain to the time of the review.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

European Association of Urology. Guidelines on paediatric urology. 2024 [internet publication].Full text

National Institute for Health and Care Excellence. Urinary tract infection in under 16s: diagnosis and management. Jul 2022 [internet publication].Full text

Mattoo TK, Shaikh N, Nelson CP. Contemporary management of urinary tract infection in children. Pediatrics. 2021 Feb;147(2):e2020012138.Full text Abstract

American College of Radiology. ACR appropriateness criteria: urinary tract infection - child. 2023 [internet publication].Full text

Peters CA, Skoog SJ, Arant BS Jr, et al; American Urological Association. Management and screening of primary vesicoureteral reflux in children: AUA guideline. 2017 [internet publication].Full text

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

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Guidelines
- Paediatric urology: urinary tract infections in children
- Guidelines on paediatric urology: urinary tract infections in children
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Patient information
Urinary tract infections in children
More Patient information
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Urinary tract infections in children

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic investigations

1st investigations to order

Investigations to consider

Treatment algorithm

vesicoureteral reflux: no history of febrile UTIs

age ≤2 months

age >2 months

recurrent UTIs

Contributors

Authors

Joana Dos Santos, MD, MHSc, FRCPC

Disclosures

Acknowledgements

Disclosures

Peer reviewers

Martin Koyle, MD, MSc, FAAP, FACS, FRCS(Eng), FRCSC

Disclosures

Daniel T. Keefe, MD, FRCSC

Disclosures

Peer reviewer acknowledgements

Disclosures

References

Key articles

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials

Guidelines

Patient information

Log in or subscribe to access all of BMJ Best Practice

Log in or subscribe to access all of BMJ Best Practice

Log in to access all of BMJ Best Practice