A urinary tract infection is an infection of the bladder, urethra, ureters, and/or kidneys and is a common infection in infancy and childhood. Risk factors include congenital anomalies of the kidneys and urinary tract (CAKUT), female sex, lack of circumcision in young boys, and bladder and bowel dysfunction. As in adults, the most common causative pathogen is Escherichia coli. Children and adolescents often present with classic symptoms of UTI (e.g., dysuria, urinary frequency). However, nonverbal and/or young children often have nonspecific symptoms, which may include fever, irritability, poor feeding, and new-onset urinary incontinence. Diagnosis is based on symptoms and urinalysis and urine culture results. Imaging is not required for diagnosis but is used to evaluate for suspected acute complications (e.g., renal abscess) and underlying structural anomalies (e.g., vesicoureteral reflux). The first-line imaging modality is renal and bladder ultrasound (RBUS); further imaging depends on the patient's history, ultrasound results, and/or specialist recommendations. Treatment of pediatric UTIs involves antibiotics (oral or IV) and management of any underlying causes. Recurrent UTIs are common in children, and patients and/or their caregivers should be educated on preventive measures. Complications of pediatric UTIs, especially if severe or recurrent, include sepsis, renal scarring, chronic kidney disease, and hypertension.
UTI in adults is discussed in a separate article; see “ .”
Risk factors for pediatric UTI 
- All ages
Children ≤ 24 months of age
- Uncircumcised boys 
- Age < 12 months
- Children > 24 months of age and adolescents
Although uncircumcised young boys are at an increased risk for UTIs, the preventative effect of circumcision on UTI development is not considered sufficient to recommend circumcision for all patients. 
- adolescents are similar to those in adults, e.g.: in children and
- Caregivers may report the following in young children:
Subtypes and variants
Atypical pediatric UTI 
- Definition: a collection of clinical features suggestive of underlying pathology or complicated infection 
Clinical features 
- Severe symptoms (e.g., sepsis, poor urine stream, raised creatinine)
- Caused by a pathogen other than E. coli
- Persistent symptoms despite 48–72 hours of antibiotics
- Complications (e.g., renal abscess)
- Personal or family history of urinary tract abnormalities (e.g., high-grade vesicoureteral reflux) 
- Abdominal or bladder mass
Determine the need for urinalysis based on age and clinical features; indications include: ; 
- Age < 2 months: any ill-appearing and/or febrile infant 
- Age 2–24 months ; 
- Age > 24 months with clinical features of pediatric UTI
- Send urine culture if:
- Imaging studies are required for:
Urine studies 
Collection methods 
- Not toilet trained
- Toilet trained:
- Positive : suggests bacteria
- Positive pyuria : suggests
- Microscopy: presence of bacteria on Gram stain and/or 
- Significant bacteriuria confirms the diagnosis.
- Thresholds vary based on collection method and across guidelines; follow local protocols. 
Imaging in pediatric UTI
- First febrile UTI in children aged ≤ 24 months 
- Atypical pediatric UTI or recurrent febrile UTIs (any age) 
RBUS should be performed during acute illness for children with persistent high fever or severe illness; for other children delaying imaging by up to 6 months may allow for better visualization. 
Renal bladder ultrasound (RBUS) 
- Preferred initial imaging modality for pediatric UTIs 
- Most structural abnormalities can be detected on RBUS.
- Does not expose the patient to radiation
- Potential findings include:
Voiding cystourethrography 
- Only used if there is high suspicion for VUR because of its invasive nature and use of radiation
- Potential findings include:
Advanced imaging 
- Nuclear medicine cystography 
- DMSA scan)  (
- Start empiric antibiotics for pediatric UTI (e.g., cephalosporins) while awaiting urine culture results.
- Screen for admission criteria.
- Adjust treatment when culture results become available.
- Provide supportive treatment, e.g., antipyretics, analgesia.
- If fever persists for > 72 hours, consider urgent imaging for pediatric UTI to rule out renal abscess. 
- Refer patients with complications or CAKUT to nephrology/urology.
- Educate patients and caregivers on prevention of pediatric UTI.
Admission criteria for pediatric UTI 
- IV antibiotics required (for indications, see “Empiric antibiotics for pediatric UTI”)
- Consider admitting patients with any of the following:
- Age 1–2 months 
- Significant renal tract anomalies 
- Barriers to follow-up
- Follow local guidelines and protocols if available.
- Always check local resistance patterns before initiating treatment.
|Empiric antibiotics for pediatric UTI |
|Indications||Recommended antibiotics||Duration |
Repeat urine culture is not necessary unless symptoms persist. 
-  (e.g., from poor hygiene, irritation)
- Appendicitis or mesenteric lymphadenitis 
- Diabetes mellitus or diabetes insipidus (may cause urinary frequency) 
- Genital injury 
- Sexually transmitted infections 
The differential diagnoses listed here are not exhaustive.
Chronic (due to recurrent UTIs) 
- Renal scarring 
We list the most important complications. The selection is not exhaustive.
- Educate caregivers on nonspecific and the need to seek early treatment.
- Promptly identify and treat any underlying conditions including:
- (see “ ”) 
- CAKUT (e.g., , )
- Encourage children to urinate regularly. 
- Consider recommending an increase in fluid intake. 
- Uncircumcised boys: Encourage daily gentle retraction of the foreskin for cleaning. 
- Discuss antibiotic prophylaxis for recurrent UTIs with a specialist; use is controversial. 
- Some evidence suggests that probiotics and cranberry supplements may prevent recurrence, but further research is required.