17:I[462708,["/_next/static/chunks/3yo3kiro3bmlp.js","/_next/static/chunks/3vr2wvd8f2efb.js","/_next/static/chunks/2vtmb68_vu-9t.js","/_next/static/chunks/2s8mt6_8wrpfo.js","/_next/static/chunks/3vkulz2i3l61y.js","/_next/static/chunks/1cqw2i1silz0i.js","/_next/static/chunks/14dbm3lm_t629.js","/_next/static/chunks/335_v2mb569ld.js","/_next/static/chunks/3ykn5ops9bft5.js","/_next/static/chunks/3cmavum774kjt.js","/_next/static/chunks/3th-0-a2xf9qs.js","/_next/static/chunks/0p0xpwde6kzmv.js","/_next/static/chunks/401-sxxnzbtf_.js","/_next/static/chunks/0wywtv698a1v0.js","/_next/static/chunks/2botzqwpnrzyj.js"],"ArticleReader"] 18:T53ac,## Summary Urinary tract infection (UTI) in children ranges from lower UTI/cystitis to febrile UTI with renal parenchymal involvement. Presentation is strongly age-dependent: young infants may have fever, poor feeding, vomiting, lethargy, jaundice, hypothermia, or sepsis without urinary symptoms, while older children more often report dysuria, frequency, urgency, suprapubic pain, flank pain, or new incontinence.[1,2] Obtain urine **before antibiotics whenever this will not delay treatment of a seriously ill child**. For toilet-trained children, use a clean midstream sample. In non-toilet-trained children, catheterization or suprapubic aspiration gives the most reliable culture specimen. Plastic collection bags have high contamination rates and should not be used to establish a positive culture diagnosis.[1] Interpret urinalysis and culture together with age, symptoms, collection method, and prior antibiotic exposure. Nitrite is specific but can be falsely negative when bladder dwell time is short. Leukocyte esterase reflects pyuria but is less specific. The 2026 European Association of Urology (EAU) guideline considers clean-catch, midstream, and catheter cultures potentially significant at approximately **10³-10⁴ CFU/mL** when a monoculture fits the clinical picture; any growth from a correctly obtained suprapubic aspirate can be significant. Mixed growth usually indicates contamination.[1] Children with sepsis physiology, dehydration that cannot be corrected orally, persistent vomiting, urinary obstruction, impaired kidney function, or complex uropathy require hospital-level care. Age thresholds differ slightly by guideline: EAU recommends parenteral therapy for newborns and infants **<2 months** because of greater urosepsis risk, while NICE directs children **<3 months** with suspected UTI to urgent pediatric specialist care and IV treatment through the young-infant fever pathway.[1,3,4] For uncomplicated lower UTI in children ≥3 months, NICE recommends a **3-day** course using local susceptibility data, with trimethoprim or nitrofurantoin among first choices.[3] For acute pyelonephritis, NICE recommends **7-10 days** of oral treatment and review of IV therapy at about 48 hours with oral step-down when possible.[4] The 2026 EAU guideline recommends **4-7 days** for febrile UTI in many children, reflecting newer duration evidence. Local pediatric antimicrobial policy should state which framework it follows.[1] Imaging is selective rather than automatic after every UTI. EAU recommends renal/bladder ultrasound for febrile UTI, within 24 hours in infants and acutely ill children, and selective VCUG for infants <1 year with febrile UTI, atypical or recurrent infection, or abnormal ultrasound.[1] NICE uses a more selective ultrasound strategy based on age, atypical features, and recurrence.[2] ## Classification ### Lower UTI Cystitis is more likely with: - dysuria; - frequency or urgency; - suprapubic discomfort; - malodorous urine; - new daytime or nighttime wetting; - little or no systemic illness. Fever, flank pain, vomiting, or systemic toxicity should raise concern for upper UTI. ### Febrile or upper UTI Febrile UTI is commonly used as a clinical proxy for renal parenchymal involvement in younger children who cannot localize pain. Acute pyelonephritis is more likely with: - fever without another source; - flank or loin pain/tenderness; - vomiting; - systemic illness; - elevated inflammatory markers; - bacteremia or sepsis.[1,2] ### Atypical UTI NICE defines atypical UTI by features associated with severe infection, obstruction, structural disease, or an unusual organism:[2] - serious illness; - poor urine flow; - abdominal or bladder mass; - elevated creatinine; - sepsis; - failure to respond to appropriate antibiotics within 48 hours; - infection with a non-*Escherichia coli* organism. ### Recurrent UTI NICE defines recurrent UTI as:[2] - at least 2 episodes of upper UTI; or - 1 upper UTI plus at least 1 lower UTI; or - at least 3 episodes of lower UTI. ## Epidemiology and microbiology UTI is one of the most common bacterial infections in infants and young children. Risk varies with age, sex, circumcision status, prior UTI, and urinary tract anatomy.[1] *E. coli* is the dominant pathogen. Non-*E. coli* organisms become more likely with prior antibiotics, instrumentation, congenital urinary tract abnormalities, neurogenic bladder, recurrent infection, and hospitalization. Organisms include *Klebsiella*, *Proteus*, *Enterobacter*, *Enterococcus*, *Pseudomonas*, and others.[1] Risk factors for resistant organisms include previous UTI, recent hospitalization, recent antimicrobial exposure, long-term prophylaxis, and known urinary tract abnormalities. Empiric treatment must therefore use local resistance data and prior urine isolates whenever available.[1,3,4] ## Risk factors - previous UTI; - vesicoureteral reflux (VUR); - congenital obstruction or hydronephrosis; - neurogenic bladder; - incomplete bladder emptying; - bladder-bowel dysfunction; - constipation; - urinary catheterization or instrumentation; - stones; - uncircumcised status in infancy; - dysfunctional voiding or habitual holding; - immunocompromise.[1] Bladder-bowel dysfunction is especially important in recurrent infection. Treating constipation and voiding dysfunction can reduce recurrence.[1] ## Clinical features by age ### Neonates and young infants Possible features include: - fever or hypothermia; - poor feeding; - vomiting; - lethargy or irritability; - poor weight gain; - jaundice; - apnea; - sepsis physiology. A young infant with suspected UTI must be evaluated through an age-appropriate serious-bacterial-infection pathway rather than treated as isolated cystitis.[1-4] ### Infants and preschool children - fever without source; - vomiting; - abdominal discomfort; - irritability; - reduced intake; - malodorous urine; - new incontinence; - dysuria or frequency when the child can report them.[2] ### School-age children and adolescents Lower UTI usually produces dysuria, frequency, urgency, suprapubic pain, hematuria, or new enuresis. Upper UTI more often adds fever, flank pain, vomiting, and systemic illness. ## Immediate risk assessment Escalate urgently for: - age <3 months with suspected UTI under NICE pathways; - sepsis physiology or altered consciousness; - poor perfusion or hypotension; - dehydration not correctable orally; - persistent vomiting; - suspected obstruction; - markedly reduced urine output; - elevated creatinine; - significant immunocompromise; - known complex uropathy; - failure of suitable outpatient therapy.[1-4] > **Caution:** Do not delay sepsis treatment because obtaining an ideal urine specimen is taking too long. Collect an appropriate sample first when feasible, but resuscitation and effective antimicrobial therapy take priority in a seriously ill child. ## Urine collection ### Toilet-trained child Use a carefully collected clean midstream sample for urinalysis and culture when culture is indicated.[1] ### Non-toilet-trained child EAU 2026 strongly recommends bladder catheterization or suprapubic aspiration when a reliable specimen is required for urinalysis and culture.[1] Clean catch can be used as a noninvasive screening method, but contamination is higher than with catheterization or suprapubic aspiration. Collection bags have contamination rates around 50-60% in the EAU evidence review and should not be used to confirm a positive culture.[1] ### Timing and handling Collect before antimicrobial treatment whenever possible. Send promptly to the laboratory; if processing is delayed, refrigerate or use the laboratory's approved preservative and transport method.[2] ## Urinalysis ### Dipstick interpretation | Leukocyte esterase | Nitrite | Interpretation / next action | |---|---|---| | Negative | Negative | UTI is less likely. In a low-risk child ≥3 months, antibiotics are usually not indicated; culture can still be needed when illness risk is high or symptoms strongly conflict with dipstick findings.[2] | | Positive | Positive | UTI is likely; obtain culture when indicated and treat if the syndrome is compatible | | Negative | Positive | Nitrite strongly supports bacteriuria; send culture and usually treat when symptoms fit | | Positive | Negative | Could be UTI or sterile pyuria; culture and interpret with age, symptoms, and clinical risk | Nitrite formation generally requires several hours of bladder dwell time, so false-negative nitrite tests are common in infants who void frequently.[1] ### Microscopy EAU uses approximately **5 WBC/high-power field** in centrifuged urine or **>10 WBC/µL** in uncentrifuged urine as useful pyuria thresholds. Pyuria supports UTI but is not organism-specific and can occur with other inflammatory conditions.[1] ## Urine culture Culture should be interpreted in context, not by a single universal CFU threshold.[1] EAU 2026 notes: - febrile UTI commonly yields ≥10⁵ CFU/mL; - clean-catch, midstream, and catheter cultures may be significant at approximately 10³-10⁴ CFU/mL when a monoculture fits the clinical syndrome; - any growth from a correctly obtained suprapubic aspirate can be significant; - mixed growth usually indicates contamination; - in febrile infants <4 months, about 10³ CFU/mL can be clinically significant when the specimen is high quality and clinical/laboratory findings agree.[1] Send urine for culture when upper UTI is suspected, the child is <3 months, illness risk is high, dipstick is positive, infection is recurrent, there is poor response, or clinical findings and dipstick do not agree.[2] ## Blood tests Blood testing is unnecessary for every uncomplicated lower UTI. In an admitted or systemically ill child consider: - CBC; - creatinine, urea, and electrolytes; - CRP; - procalcitonin when it contributes to risk assessment; - blood cultures before antibiotics when bacteremia or sepsis is suspected.[1] EAU cites procalcitonin >1 ng/mL as associated with renal parenchymal involvement in young children, but it is not a stand-alone diagnostic criterion.[1] ## Differential diagnosis Consider: - vulvovaginitis or balanitis; - urethritis, including sexually transmitted infection in an appropriate adolescent context; - appendicitis; - gastroenteritis; - constipation; - nephrolithiasis; - glomerulonephritis; - interstitial nephritis; - inflammatory disorders causing sterile pyuria; - diabetes mellitus when polyuria is prominent; - urinary obstruction when flow is poor.[1,2] ## Antimicrobial treatment Choose therapy according to age, lower versus upper infection, illness severity, recent antibiotic exposure, prior isolates, allergy history, renal function, and the local antibiogram.[1,3,4] ### Young infants NICE: children **<3 months** with suspected UTI require urgent pediatric specialist care and IV therapy within the local young-infant fever/sepsis pathway.[3,4] EAU: newborns and infants **<2 months** with febrile UTI should generally receive parenteral therapy because urosepsis and severe pyelonephritis are more common.[1] This age-threshold difference is jurisdictional. Local neonatal/young-infant sepsis policy takes precedence. ### Uncomplicated lower UTI, age ≥3 months NICE recommends **3 days** for uncomplicated lower UTI.[3] | Drug | NICE pediatric dose | Course | |---|---|---| | Trimethoprim when resistance risk is low | 3-5 months: 4 mg/kg (max 200 mg) or 25 mg twice daily; 6 months-5 years: 4 mg/kg (max 200 mg) or 50 mg twice daily; 6-11 years: 4 mg/kg (max 200 mg) or 100 mg twice daily; 12-15 years: 200 mg twice daily | 3 days | | Nitrofurantoin when renal function is adequate | 3 months-11 years: 750 micrograms/kg four times daily; 12-15 years: 50 mg four times daily or 100 mg modified-release twice daily | 3 days | Second-choice NICE options include nitrofurantoin if not already used, culture-directed amoxicillin, or cefalexin. Use local licensing and formulary rules.[3] Nitrofurantoin is appropriate for lower UTI but should **not** be used to treat pyelonephritis because it does not achieve adequate renal tissue concentrations.[4] ### Acute pyelonephritis / febrile upper UTI, age ≥3 months Oral therapy is appropriate for many children who are not severely ill, can retain medication, and have reliable follow-up.[4] NICE first-choice oral therapy includes cefalexin:[4] | Age | Cefalexin dose | Duration | |---|---|---| | 3-11 months | 12.5 mg/kg or 125 mg twice daily; higher severe-infection dosing may be used within pediatric maximums | 7-10 days | | 1-4 years | 12.5 mg/kg twice daily or 125 mg three times daily | 7-10 days | | 5-11 years | 12.5 mg/kg twice daily or 250 mg three times daily | 7-10 days | | 12-15 years | 500 mg twice or three times daily; higher dosing can be used for severe infection within formulary limits | 7-10 days | Co-amoxiclav is an alternative only when culture confirms susceptibility under NICE guidance.[4] ### When IV therapy is needed Use parenteral treatment for severe systemic illness, inability to tolerate oral medication, sepsis, suspected obstruction, or another high-risk feature.[1,4] NICE options for children ≥3 months include:[4] - **ceftriaxone:** 50-80 mg/kg IV once daily in children up to 50 kg, maximum 4 g/day; older/larger children commonly receive 1-2 g once daily; - **cefuroxime:** 20 mg/kg IV three times daily, maximum 750 mg per dose, with higher severe-infection dosing under specialist guidance; - **gentamicin:** initial 7 mg/kg IV once daily, then adjust using drug concentrations and renal function; - **amikacin:** initial 15 mg/kg IV once daily, then adjust using drug concentrations and renal function. Review IV therapy at about **48 hours** and step down to oral treatment when clinically appropriate.[4] > **Caution:** Aminoglycosides require renal-function assessment and therapeutic drug monitoring. Neonatal antibiotic choices and ceftriaxone restrictions are age-specific; do not extrapolate the ≥3-month regimen to neonates. ### Duration differences between current guidelines - **EAU 2026:** febrile UTI, 4-7 days in many children; simple cystitis, 3-5 days.[1] - **NICE:** lower UTI in children ≥3 months, 3 days; oral pyelonephritis, 7-10 days; IV therapy reviewed at 48 hours with oral step-down when appropriate.[3,4] These differences reflect evolving evidence and differing national stewardship frameworks. Follow the local pediatric pathway and culture data. ## Response to treatment and treatment failure Most children receiving effective therapy improve clinically within 24-48 hours.[1] Failure to improve by 48 hours should prompt review of: - culture and susceptibility; - adherence and absorption; - resistant organism; - wrong diagnosis; - urinary obstruction; - renal or perinephric abscess; - infected stone; - urinary retention; - congenital urinary tract abnormality.[1,2] EAU recommends repeat ultrasound when fever persists or response is poor. Consider urinary drainage when infection remains unresponsive and obstruction, retention, or an infected collecting system is present.[1] ## Imaging after UTI ### EAU 2026 approach EAU recommends renal/bladder ultrasound in children with febrile UTI, performed **within 24 hours in infants and acutely ill children**. In toilet-trained children, pre- and post-void imaging can assess post-void residual and clues to bladder-bowel dysfunction.[1] EAU suggests selective VCUG during follow-up for: - first febrile UTI in an infant <1 year; - recurrent febrile UTI; - atypical UTI; - abnormal ultrasound; - abnormal DMSA in a top-down pathway.[1] DMSA can be considered at least 6 months after febrile UTI to assess persistent renal scarring, although routine use has declined because of radiation exposure and more selective imaging strategies.[1] ### NICE approach NICE uses a more selective imaging schedule:[2] - **Atypical UTI:** ultrasound during the acute infection. - **First UTI in an infant <6 months that responds well:** ultrasound within 6 weeks. - **Recurrent UTI:** ultrasound and selective DMSA according to age and recurrence pattern. - **VCUG/MCUG:** not routine; consider when ultrasound shows dilation, urine flow is poor, infection is non-*E. coli*, or there is a family history of VUR.[2] > **Current practice:** Imaging after childhood UTI is one of the clearest areas of guideline variation. Apply one coherent local pathway rather than mixing thresholds from different jurisdictions. ## Vesicoureteral reflux and recurrent UTI VUR increases recurrence risk, especially when dilating/high grade and accompanied by bladder-bowel dysfunction. Management depends on age, reflux grade, febrile recurrence, renal abnormalities, and family preferences. Not every child with VUR needs continuous antimicrobial prophylaxis. EAU supports prophylaxis for selected children at high risk of recurrence, including some with urinary tract abnormalities and children with VUR plus bladder-bowel dysfunction while voiding dysfunction is being corrected.[1] NICE advises against routine prophylactic antibiotics after a first UTI.[2] ## Bladder-bowel dysfunction Assess every toilet-trained child with recurrent or febrile UTI for: - constipation; - infrequent voiding; - urgency; - daytime wetting; - holding maneuvers; - incomplete emptying; - elevated post-void residual when indicated.[1] Treat constipation, establish regular voiding, optimize hydration, and refer for pediatric urology/continence care when symptoms persist. EAU strongly recommends identifying and treating bladder-bowel dysfunction because it lowers recurrent UTI risk.[1] ## Prevention - Encourage regular voiding and adequate hydration. - Treat constipation and bladder-bowel dysfunction. - Optimize catheterization technique in neurogenic bladder. - Avoid unnecessary antibiotic prophylaxis. - Use targeted prophylaxis only when recurrence risk and anatomy justify it. - Ensure families know to obtain early urine testing for future unexplained fever when recurrence risk is high.[1,2] EAU reports moderate evidence that cranberry products can reduce recurrence in selected children with normal urinary tracts, but supplements should not replace investigation and treatment of structural or voiding abnormalities.[1] ## Disposition and follow-up ### Consider outpatient treatment when - age is outside high-risk young-infant thresholds; - the child is hemodynamically stable; - oral intake and medication are tolerated; - there is no suspected obstruction or severe uropathy; - caregivers can obtain medications and return promptly; - follow-up of culture results is reliable. ### Admit or urgently refer when - sepsis or hemodynamic instability is present; - the child is a high-risk young infant; - there is persistent vomiting or dehydration; - oral therapy cannot be taken; - obstruction or significant renal impairment is suspected; - complex urinary anatomy or immunocompromise raises risk; - outpatient therapy has failed. Follow-up must include a system to review culture results and narrow, change, or stop antibiotics when appropriate. Recurrent febrile UTI, abnormal imaging, poor urine flow, or suspected bladder dysfunction warrants pediatric/urology review. ## Acute management checklist - Assess age, perfusion, hydration, and sepsis risk. - Obtain urine before antibiotics when this does not delay urgent treatment. - Use midstream urine in toilet-trained children; catheterization or suprapubic aspiration for reliable culture in non-toilet-trained children. - Perform dipstick/urinalysis and send culture when upper UTI, young age, high illness risk, recurrence, positive dipstick, discordant findings, or treatment failure makes culture important. - Start empiric antibiotics promptly for febrile/upper UTI; use local resistance data and previous cultures. - Use parenteral therapy for severe illness, high-risk young infants, inability to take oral medication, or complicated infection. - Review culture and clinical response within 24-48 hours. - Reassess urgently if fever or systemic illness persists; consider resistant bacteria, obstruction, abscess, or wrong diagnosis. - Apply the local imaging pathway after febrile, atypical, or recurrent UTI. - Identify constipation and bladder-bowel dysfunction before labeling recurrent infections as unavoidable. ## References 1. European Association of Urology. EAU Guidelines on Paediatric Urology: Urinary Tract Infections in Children. 2026 edition. https://uroweb.org/guidelines/paediatric-urology/chapter/urinary-tract-infections-in-children 2. National Institute for Health and Care Excellence. *Urinary tract infection in under 16s: diagnosis and management (NG224).* Published 2022; current online recommendations accessed 2026. https://www.nice.org.uk/guidance/ng224/chapter/Recommendations 3. National Institute for Health and Care Excellence. *Urinary tract infection (lower): antimicrobial prescribing (NG109).* Published 2018; current online recommendations accessed 2026. https://www.nice.org.uk/guidance/ng109/chapter/Recommendations 4. National Institute for Health and Care Excellence. *Pyelonephritis (acute): antimicrobial prescribing (NG111).* Published 2018; current online recommendations accessed 2026. https://www.nice.org.uk/guidance/NG111/chapter/recommendations19:T53ac,## Summary Urinary tract infection (UTI) in children ranges from lower UTI/cystitis to febrile UTI with renal parenchymal involvement. Presentation is strongly age-dependent: young infants may have fever, poor feeding, vomiting, lethargy, jaundice, hypothermia, or sepsis without urinary symptoms, while older children more often report dysuria, frequency, urgency, suprapubic pain, flank pain, or new incontinence.[1,2] Obtain urine **before antibiotics whenever this will not delay treatment of a seriously ill child**. For toilet-trained children, use a clean midstream sample. In non-toilet-trained children, catheterization or suprapubic aspiration gives the most reliable culture specimen. Plastic collection bags have high contamination rates and should not be used to establish a positive culture diagnosis.[1] Interpret urinalysis and culture together with age, symptoms, collection method, and prior antibiotic exposure. Nitrite is specific but can be falsely negative when bladder dwell time is short. Leukocyte esterase reflects pyuria but is less specific. The 2026 European Association of Urology (EAU) guideline considers clean-catch, midstream, and catheter cultures potentially significant at approximately **10³-10⁴ CFU/mL** when a monoculture fits the clinical picture; any growth from a correctly obtained suprapubic aspirate can be significant. Mixed growth usually indicates contamination.[1] Children with sepsis physiology, dehydration that cannot be corrected orally, persistent vomiting, urinary obstruction, impaired kidney function, or complex uropathy require hospital-level care. Age thresholds differ slightly by guideline: EAU recommends parenteral therapy for newborns and infants **<2 months** because of greater urosepsis risk, while NICE directs children **<3 months** with suspected UTI to urgent pediatric specialist care and IV treatment through the young-infant fever pathway.[1,3,4] For uncomplicated lower UTI in children ≥3 months, NICE recommends a **3-day** course using local susceptibility data, with trimethoprim or nitrofurantoin among first choices.[3] For acute pyelonephritis, NICE recommends **7-10 days** of oral treatment and review of IV therapy at about 48 hours with oral step-down when possible.[4] The 2026 EAU guideline recommends **4-7 days** for febrile UTI in many children, reflecting newer duration evidence. Local pediatric antimicrobial policy should state which framework it follows.[1] Imaging is selective rather than automatic after every UTI. EAU recommends renal/bladder ultrasound for febrile UTI, within 24 hours in infants and acutely ill children, and selective VCUG for infants <1 year with febrile UTI, atypical or recurrent infection, or abnormal ultrasound.[1] NICE uses a more selective ultrasound strategy based on age, atypical features, and recurrence.[2] ## Classification ### Lower UTI Cystitis is more likely with: - dysuria; - frequency or urgency; - suprapubic discomfort; - malodorous urine; - new daytime or nighttime wetting; - little or no systemic illness. Fever, flank pain, vomiting, or systemic toxicity should raise concern for upper UTI. ### Febrile or upper UTI Febrile UTI is commonly used as a clinical proxy for renal parenchymal involvement in younger children who cannot localize pain. Acute pyelonephritis is more likely with: - fever without another source; - flank or loin pain/tenderness; - vomiting; - systemic illness; - elevated inflammatory markers; - bacteremia or sepsis.[1,2] ### Atypical UTI NICE defines atypical UTI by features associated with severe infection, obstruction, structural disease, or an unusual organism:[2] - serious illness; - poor urine flow; - abdominal or bladder mass; - elevated creatinine; - sepsis; - failure to respond to appropriate antibiotics within 48 hours; - infection with a non-*Escherichia coli* organism. ### Recurrent UTI NICE defines recurrent UTI as:[2] - at least 2 episodes of upper UTI; or - 1 upper UTI plus at least 1 lower UTI; or - at least 3 episodes of lower UTI. ## Epidemiology and microbiology UTI is one of the most common bacterial infections in infants and young children. Risk varies with age, sex, circumcision status, prior UTI, and urinary tract anatomy.[1] *E. coli* is the dominant pathogen. Non-*E. coli* organisms become more likely with prior antibiotics, instrumentation, congenital urinary tract abnormalities, neurogenic bladder, recurrent infection, and hospitalization. Organisms include *Klebsiella*, *Proteus*, *Enterobacter*, *Enterococcus*, *Pseudomonas*, and others.[1] Risk factors for resistant organisms include previous UTI, recent hospitalization, recent antimicrobial exposure, long-term prophylaxis, and known urinary tract abnormalities. Empiric treatment must therefore use local resistance data and prior urine isolates whenever available.[1,3,4] ## Risk factors - previous UTI; - vesicoureteral reflux (VUR); - congenital obstruction or hydronephrosis; - neurogenic bladder; - incomplete bladder emptying; - bladder-bowel dysfunction; - constipation; - urinary catheterization or instrumentation; - stones; - uncircumcised status in infancy; - dysfunctional voiding or habitual holding; - immunocompromise.[1] Bladder-bowel dysfunction is especially important in recurrent infection. Treating constipation and voiding dysfunction can reduce recurrence.[1] ## Clinical features by age ### Neonates and young infants Possible features include: - fever or hypothermia; - poor feeding; - vomiting; - lethargy or irritability; - poor weight gain; - jaundice; - apnea; - sepsis physiology. A young infant with suspected UTI must be evaluated through an age-appropriate serious-bacterial-infection pathway rather than treated as isolated cystitis.[1-4] ### Infants and preschool children - fever without source; - vomiting; - abdominal discomfort; - irritability; - reduced intake; - malodorous urine; - new incontinence; - dysuria or frequency when the child can report them.[2] ### School-age children and adolescents Lower UTI usually produces dysuria, frequency, urgency, suprapubic pain, hematuria, or new enuresis. Upper UTI more often adds fever, flank pain, vomiting, and systemic illness. ## Immediate risk assessment Escalate urgently for: - age <3 months with suspected UTI under NICE pathways; - sepsis physiology or altered consciousness; - poor perfusion or hypotension; - dehydration not correctable orally; - persistent vomiting; - suspected obstruction; - markedly reduced urine output; - elevated creatinine; - significant immunocompromise; - known complex uropathy; - failure of suitable outpatient therapy.[1-4] > **Caution:** Do not delay sepsis treatment because obtaining an ideal urine specimen is taking too long. Collect an appropriate sample first when feasible, but resuscitation and effective antimicrobial therapy take priority in a seriously ill child. ## Urine collection ### Toilet-trained child Use a carefully collected clean midstream sample for urinalysis and culture when culture is indicated.[1] ### Non-toilet-trained child EAU 2026 strongly recommends bladder catheterization or suprapubic aspiration when a reliable specimen is required for urinalysis and culture.[1] Clean catch can be used as a noninvasive screening method, but contamination is higher than with catheterization or suprapubic aspiration. Collection bags have contamination rates around 50-60% in the EAU evidence review and should not be used to confirm a positive culture.[1] ### Timing and handling Collect before antimicrobial treatment whenever possible. Send promptly to the laboratory; if processing is delayed, refrigerate or use the laboratory's approved preservative and transport method.[2] ## Urinalysis ### Dipstick interpretation | Leukocyte esterase | Nitrite | Interpretation / next action | |---|---|---| | Negative | Negative | UTI is less likely. In a low-risk child ≥3 months, antibiotics are usually not indicated; culture can still be needed when illness risk is high or symptoms strongly conflict with dipstick findings.[2] | | Positive | Positive | UTI is likely; obtain culture when indicated and treat if the syndrome is compatible | | Negative | Positive | Nitrite strongly supports bacteriuria; send culture and usually treat when symptoms fit | | Positive | Negative | Could be UTI or sterile pyuria; culture and interpret with age, symptoms, and clinical risk | Nitrite formation generally requires several hours of bladder dwell time, so false-negative nitrite tests are common in infants who void frequently.[1] ### Microscopy EAU uses approximately **5 WBC/high-power field** in centrifuged urine or **>10 WBC/µL** in uncentrifuged urine as useful pyuria thresholds. Pyuria supports UTI but is not organism-specific and can occur with other inflammatory conditions.[1] ## Urine culture Culture should be interpreted in context, not by a single universal CFU threshold.[1] EAU 2026 notes: - febrile UTI commonly yields ≥10⁵ CFU/mL; - clean-catch, midstream, and catheter cultures may be significant at approximately 10³-10⁴ CFU/mL when a monoculture fits the clinical syndrome; - any growth from a correctly obtained suprapubic aspirate can be significant; - mixed growth usually indicates contamination; - in febrile infants <4 months, about 10³ CFU/mL can be clinically significant when the specimen is high quality and clinical/laboratory findings agree.[1] Send urine for culture when upper UTI is suspected, the child is <3 months, illness risk is high, dipstick is positive, infection is recurrent, there is poor response, or clinical findings and dipstick do not agree.[2] ## Blood tests Blood testing is unnecessary for every uncomplicated lower UTI. In an admitted or systemically ill child consider: - CBC; - creatinine, urea, and electrolytes; - CRP; - procalcitonin when it contributes to risk assessment; - blood cultures before antibiotics when bacteremia or sepsis is suspected.[1] EAU cites procalcitonin >1 ng/mL as associated with renal parenchymal involvement in young children, but it is not a stand-alone diagnostic criterion.[1] ## Differential diagnosis Consider: - vulvovaginitis or balanitis; - urethritis, including sexually transmitted infection in an appropriate adolescent context; - appendicitis; - gastroenteritis; - constipation; - nephrolithiasis; - glomerulonephritis; - interstitial nephritis; - inflammatory disorders causing sterile pyuria; - diabetes mellitus when polyuria is prominent; - urinary obstruction when flow is poor.[1,2] ## Antimicrobial treatment Choose therapy according to age, lower versus upper infection, illness severity, recent antibiotic exposure, prior isolates, allergy history, renal function, and the local antibiogram.[1,3,4] ### Young infants NICE: children **<3 months** with suspected UTI require urgent pediatric specialist care and IV therapy within the local young-infant fever/sepsis pathway.[3,4] EAU: newborns and infants **<2 months** with febrile UTI should generally receive parenteral therapy because urosepsis and severe pyelonephritis are more common.[1] This age-threshold difference is jurisdictional. Local neonatal/young-infant sepsis policy takes precedence. ### Uncomplicated lower UTI, age ≥3 months NICE recommends **3 days** for uncomplicated lower UTI.[3] | Drug | NICE pediatric dose | Course | |---|---|---| | Trimethoprim when resistance risk is low | 3-5 months: 4 mg/kg (max 200 mg) or 25 mg twice daily; 6 months-5 years: 4 mg/kg (max 200 mg) or 50 mg twice daily; 6-11 years: 4 mg/kg (max 200 mg) or 100 mg twice daily; 12-15 years: 200 mg twice daily | 3 days | | Nitrofurantoin when renal function is adequate | 3 months-11 years: 750 micrograms/kg four times daily; 12-15 years: 50 mg four times daily or 100 mg modified-release twice daily | 3 days | Second-choice NICE options include nitrofurantoin if not already used, culture-directed amoxicillin, or cefalexin. Use local licensing and formulary rules.[3] Nitrofurantoin is appropriate for lower UTI but should **not** be used to treat pyelonephritis because it does not achieve adequate renal tissue concentrations.[4] ### Acute pyelonephritis / febrile upper UTI, age ≥3 months Oral therapy is appropriate for many children who are not severely ill, can retain medication, and have reliable follow-up.[4] NICE first-choice oral therapy includes cefalexin:[4] | Age | Cefalexin dose | Duration | |---|---|---| | 3-11 months | 12.5 mg/kg or 125 mg twice daily; higher severe-infection dosing may be used within pediatric maximums | 7-10 days | | 1-4 years | 12.5 mg/kg twice daily or 125 mg three times daily | 7-10 days | | 5-11 years | 12.5 mg/kg twice daily or 250 mg three times daily | 7-10 days | | 12-15 years | 500 mg twice or three times daily; higher dosing can be used for severe infection within formulary limits | 7-10 days | Co-amoxiclav is an alternative only when culture confirms susceptibility under NICE guidance.[4] ### When IV therapy is needed Use parenteral treatment for severe systemic illness, inability to tolerate oral medication, sepsis, suspected obstruction, or another high-risk feature.[1,4] NICE options for children ≥3 months include:[4] - **ceftriaxone:** 50-80 mg/kg IV once daily in children up to 50 kg, maximum 4 g/day; older/larger children commonly receive 1-2 g once daily; - **cefuroxime:** 20 mg/kg IV three times daily, maximum 750 mg per dose, with higher severe-infection dosing under specialist guidance; - **gentamicin:** initial 7 mg/kg IV once daily, then adjust using drug concentrations and renal function; - **amikacin:** initial 15 mg/kg IV once daily, then adjust using drug concentrations and renal function. Review IV therapy at about **48 hours** and step down to oral treatment when clinically appropriate.[4] > **Caution:** Aminoglycosides require renal-function assessment and therapeutic drug monitoring. Neonatal antibiotic choices and ceftriaxone restrictions are age-specific; do not extrapolate the ≥3-month regimen to neonates. ### Duration differences between current guidelines - **EAU 2026:** febrile UTI, 4-7 days in many children; simple cystitis, 3-5 days.[1] - **NICE:** lower UTI in children ≥3 months, 3 days; oral pyelonephritis, 7-10 days; IV therapy reviewed at 48 hours with oral step-down when appropriate.[3,4] These differences reflect evolving evidence and differing national stewardship frameworks. Follow the local pediatric pathway and culture data. ## Response to treatment and treatment failure Most children receiving effective therapy improve clinically within 24-48 hours.[1] Failure to improve by 48 hours should prompt review of: - culture and susceptibility; - adherence and absorption; - resistant organism; - wrong diagnosis; - urinary obstruction; - renal or perinephric abscess; - infected stone; - urinary retention; - congenital urinary tract abnormality.[1,2] EAU recommends repeat ultrasound when fever persists or response is poor. Consider urinary drainage when infection remains unresponsive and obstruction, retention, or an infected collecting system is present.[1] ## Imaging after UTI ### EAU 2026 approach EAU recommends renal/bladder ultrasound in children with febrile UTI, performed **within 24 hours in infants and acutely ill children**. In toilet-trained children, pre- and post-void imaging can assess post-void residual and clues to bladder-bowel dysfunction.[1] EAU suggests selective VCUG during follow-up for: - first febrile UTI in an infant <1 year; - recurrent febrile UTI; - atypical UTI; - abnormal ultrasound; - abnormal DMSA in a top-down pathway.[1] DMSA can be considered at least 6 months after febrile UTI to assess persistent renal scarring, although routine use has declined because of radiation exposure and more selective imaging strategies.[1] ### NICE approach NICE uses a more selective imaging schedule:[2] - **Atypical UTI:** ultrasound during the acute infection. - **First UTI in an infant <6 months that responds well:** ultrasound within 6 weeks. - **Recurrent UTI:** ultrasound and selective DMSA according to age and recurrence pattern. - **VCUG/MCUG:** not routine; consider when ultrasound shows dilation, urine flow is poor, infection is non-*E. coli*, or there is a family history of VUR.[2] > **Current practice:** Imaging after childhood UTI is one of the clearest areas of guideline variation. Apply one coherent local pathway rather than mixing thresholds from different jurisdictions. ## Vesicoureteral reflux and recurrent UTI VUR increases recurrence risk, especially when dilating/high grade and accompanied by bladder-bowel dysfunction. Management depends on age, reflux grade, febrile recurrence, renal abnormalities, and family preferences. Not every child with VUR needs continuous antimicrobial prophylaxis. EAU supports prophylaxis for selected children at high risk of recurrence, including some with urinary tract abnormalities and children with VUR plus bladder-bowel dysfunction while voiding dysfunction is being corrected.[1] NICE advises against routine prophylactic antibiotics after a first UTI.[2] ## Bladder-bowel dysfunction Assess every toilet-trained child with recurrent or febrile UTI for: - constipation; - infrequent voiding; - urgency; - daytime wetting; - holding maneuvers; - incomplete emptying; - elevated post-void residual when indicated.[1] Treat constipation, establish regular voiding, optimize hydration, and refer for pediatric urology/continence care when symptoms persist. EAU strongly recommends identifying and treating bladder-bowel dysfunction because it lowers recurrent UTI risk.[1] ## Prevention - Encourage regular voiding and adequate hydration. - Treat constipation and bladder-bowel dysfunction. - Optimize catheterization technique in neurogenic bladder. - Avoid unnecessary antibiotic prophylaxis. - Use targeted prophylaxis only when recurrence risk and anatomy justify it. - Ensure families know to obtain early urine testing for future unexplained fever when recurrence risk is high.[1,2] EAU reports moderate evidence that cranberry products can reduce recurrence in selected children with normal urinary tracts, but supplements should not replace investigation and treatment of structural or voiding abnormalities.[1] ## Disposition and follow-up ### Consider outpatient treatment when - age is outside high-risk young-infant thresholds; - the child is hemodynamically stable; - oral intake and medication are tolerated; - there is no suspected obstruction or severe uropathy; - caregivers can obtain medications and return promptly; - follow-up of culture results is reliable. ### Admit or urgently refer when - sepsis or hemodynamic instability is present; - the child is a high-risk young infant; - there is persistent vomiting or dehydration; - oral therapy cannot be taken; - obstruction or significant renal impairment is suspected; - complex urinary anatomy or immunocompromise raises risk; - outpatient therapy has failed. Follow-up must include a system to review culture results and narrow, change, or stop antibiotics when appropriate. Recurrent febrile UTI, abnormal imaging, poor urine flow, or suspected bladder dysfunction warrants pediatric/urology review. ## Acute management checklist - Assess age, perfusion, hydration, and sepsis risk. - Obtain urine before antibiotics when this does not delay urgent treatment. - Use midstream urine in toilet-trained children; catheterization or suprapubic aspiration for reliable culture in non-toilet-trained children. - Perform dipstick/urinalysis and send culture when upper UTI, young age, high illness risk, recurrence, positive dipstick, discordant findings, or treatment failure makes culture important. - Start empiric antibiotics promptly for febrile/upper UTI; use local resistance data and previous cultures. - Use parenteral therapy for severe illness, high-risk young infants, inability to take oral medication, or complicated infection. - Review culture and clinical response within 24-48 hours. - Reassess urgently if fever or systemic illness persists; consider resistant bacteria, obstruction, abscess, or wrong diagnosis. - Apply the local imaging pathway after febrile, atypical, or recurrent UTI. - Identify constipation and bladder-bowel dysfunction before labeling recurrent infections as unavoidable. ## References 1. European Association of Urology. EAU Guidelines on Paediatric Urology: Urinary Tract Infections in Children. 2026 edition. https://uroweb.org/guidelines/paediatric-urology/chapter/urinary-tract-infections-in-children 2. National Institute for Health and Care Excellence. *Urinary tract infection in under 16s: diagnosis and management (NG224).* Published 2022; current online recommendations accessed 2026. https://www.nice.org.uk/guidance/ng224/chapter/Recommendations 3. National Institute for Health and Care Excellence. *Urinary tract infection (lower): antimicrobial prescribing (NG109).* Published 2018; current online recommendations accessed 2026. https://www.nice.org.uk/guidance/ng109/chapter/Recommendations 4. National Institute for Health and Care Excellence. *Pyelonephritis (acute): antimicrobial prescribing (NG111).* Published 2018; current online recommendations accessed 2026. https://www.nice.org.uk/guidance/NG111/chapter/recommendations7:["$","$L17",null,{"article":{"id":"medical-urinary-tract-infection-in-children","title":"Urinary Tract Infection in Children","slug":"urinary-tract-infection-in-children","description":"Urinary tract infection (UTI) in children ranges from lower UTI/cystitis to febrile UTI with renal parenchymal involvement. Presentation is strongly age-dependent: young infants may have fever, poor feeding, vomiting,…","aliases":[],"category":"Pediatrics","tags":["Pediatrics"],"updatedAt":"$undefined","body":"$18","headings":[{"id":"summary","text":"Summary","level":2},{"id":"classification","text":"Classification","level":2},{"id":"lower-uti","text":"Lower UTI","level":3},{"id":"febrile-or-upper-uti","text":"Febrile or upper UTI","level":3},{"id":"atypical-uti","text":"Atypical UTI","level":3},{"id":"recurrent-uti","text":"Recurrent UTI","level":3},{"id":"epidemiology-and-microbiology","text":"Epidemiology and microbiology","level":2},{"id":"risk-factors","text":"Risk factors","level":2},{"id":"clinical-features-by-age","text":"Clinical features by age","level":2},{"id":"neonates-and-young-infants","text":"Neonates and young infants","level":3},{"id":"infants-and-preschool-children","text":"Infants and preschool children","level":3},{"id":"school-age-children-and-adolescents","text":"School-age children and adolescents","level":3},{"id":"immediate-risk-assessment","text":"Immediate risk assessment","level":2},{"id":"urine-collection","text":"Urine collection","level":2},{"id":"toilet-trained-child","text":"Toilet-trained child","level":3},{"id":"non-toilet-trained-child","text":"Non-toilet-trained child","level":3},{"id":"timing-and-handling","text":"Timing and handling","level":3},{"id":"urinalysis","text":"Urinalysis","level":2},{"id":"dipstick-interpretation","text":"Dipstick interpretation","level":3},{"id":"microscopy","text":"Microscopy","level":3},{"id":"urine-culture","text":"Urine culture","level":2},{"id":"blood-tests","text":"Blood tests","level":2},{"id":"differential-diagnosis","text":"Differential diagnosis","level":2},{"id":"antimicrobial-treatment","text":"Antimicrobial treatment","level":2},{"id":"young-infants","text":"Young infants","level":3},{"id":"uncomplicated-lower-uti-age-3-months","text":"Uncomplicated lower UTI, age ≥3 months","level":3},{"id":"acute-pyelonephritis-febrile-upper-uti-age-3-months","text":"Acute pyelonephritis / febrile upper UTI, age ≥3 months","level":3},{"id":"when-iv-therapy-is-needed","text":"When IV therapy is needed","level":3},{"id":"duration-differences-between-current-guidelines","text":"Duration differences between current guidelines","level":3},{"id":"response-to-treatment-and-treatment-failure","text":"Response to treatment and treatment failure","level":2},{"id":"imaging-after-uti","text":"Imaging after UTI","level":2},{"id":"eau-2026-approach","text":"EAU 2026 approach","level":3},{"id":"nice-approach","text":"NICE approach","level":3},{"id":"vesicoureteral-reflux-and-recurrent-uti","text":"Vesicoureteral reflux and recurrent UTI","level":2},{"id":"bladder-bowel-dysfunction","text":"Bladder-bowel dysfunction","level":2},{"id":"prevention","text":"Prevention","level":2},{"id":"disposition-and-follow-up","text":"Disposition and follow-up","level":2},{"id":"consider-outpatient-treatment-when","text":"Consider outpatient treatment when","level":3},{"id":"admit-or-urgently-refer-when","text":"Admit or urgently refer when","level":3},{"id":"acute-management-checklist","text":"Acute management checklist","level":2},{"id":"references","text":"References","level":2}],"readingMinutes":14},"linkedMarkdown":"$19","backlinks":[],"related":[],"previewBySlug":{"abcde-approach":{"title":"ABCDE Approach","description":"The ABCDE approach is a structured method for the immediate assessment and treatment of a deteriorating or critically ill patient: Airway, Breathing, Circulation, Disability, Exposure. 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