What are the key points to cover when discussing urinary tract infections (UTIs) in children, including clinical presentation, diagnosis, and treatment?

Urinary Tract Infections in Children: Clinical and Shelf-Relevant Presentation

The diagnosis and management of urinary tract infections (UTIs) in children requires proper specimen collection, accurate diagnosis based on both pyuria and significant bacteriuria (≥50,000 CFU/mL), and prompt treatment with appropriate antibiotics for 7-14 days to prevent renal scarring. 1

Epidemiology and Significance

• UTIs are among the most common bacterial infections in children, with the urinary tract being the most frequent site of occult serious bacterial infections in febrile infants 1
• Prevalence is approximately 5% in febrile infants and young children 2-24 months of age 1
• Risk factors vary by age and sex: uncircumcised males have higher risk in infancy, while females have higher risk beyond infancy 2, 3
• Early diagnosis and treatment are critical to preserve renal function of the growing kidney 2

Clinical Presentation

• Presentation varies by age:
  • Infants and young children (2-24 months): often nonspecific with fever as the only symptom 1
  • Older children: may present with specific urinary symptoms including dysuria, frequency, urgency, hematuria, abdominal/back pain, or new daytime incontinence 4
• Consider UTI in any infant or young child with unexplained fever ≥38.0°C (100.4°F) 1
• Delays in diagnosis and treatment increase risk of renal scarring 2

Diagnosis

• Proper specimen collection is essential to avoid contamination and misdiagnosis 5:
  • Toilet-trained children: clean-catch midstream urine sample
  • Non-toilet-trained children: catheterization or suprapubic aspiration (SPA)
  • Bag urine specimens are acceptable for urinalysis but NOT for culture due to high contamination rates 4
• Diagnostic criteria for UTI requires BOTH 1, 5:
  • Pyuria (white blood cells in urine)
  • ≥50,000 CFU/mL of a single uropathogen from an appropriately collected specimen
• Urinalysis alone cannot provide a definitive diagnosis 1
• Most common pathogens:
  • Escherichia coli (most common) 3
  • Other Enterobacteriaceae (Klebsiella, Proteus, Enterobacter) 6, 2

Treatment

• Initiate antibiotics promptly after obtaining urine for culture 5
• Route of administration:
  • Oral antibiotics are appropriate for most children who appear well and can tolerate oral intake 5
  • Parenteral therapy for toxic-appearing children or those unable to tolerate oral medications 5
• First-line oral options:
  • Trimethoprim-sulfamethoxazole: 8 mg/kg trimethoprim component daily divided every 12 hours 6
  • Cephalosporins (e.g., cefixime) 5, 7
  • Amoxicillin-clavulanate 5
• Duration of therapy:
  • 7-14 days for febrile UTIs 1, 5
  • Shorter courses (1-3 days) are inadequate for febrile UTIs 5
• Adjust therapy based on culture results and clinical response 5

Imaging

• Renal and bladder ultrasonography (RBUS) is recommended for:
  • All children <2 years with first febrile UTI 1
  • Older children with recurrent UTIs 4
• Purpose: to detect anatomic abnormalities requiring further evaluation 1
• Voiding cystourethrography (VCUG) is NOT routinely recommended after first UTI 1
• VCUG is indicated if 1:
  • RBUS reveals hydronephrosis, scarring, or findings suggestive of high-grade vesicoureteral reflux (VUR) or obstructive uropathy
  • Recurrence of febrile UTI
  • Atypical or complex clinical circumstances

Follow-up and Prevention

• Parents should seek prompt medical evaluation (within 48 hours) for future febrile illnesses 1
• Obtain urine specimen at onset of subsequent febrile illnesses in children with history of UTI 1
• Antimicrobial prophylaxis is not routinely recommended for children with first UTI without VUR or with grade I-IV VUR 1
• Evaluate and treat underlying conditions that may contribute to recurrent UTIs:
  • Constipation 2, 8
  • Voiding dysfunction 8

Complications and Long-term Outcomes

• Renal scarring is the most significant long-term complication 3
• Risk factors for renal scarring:
  • Delayed treatment (>48 hours after fever onset) 3
  • Recurrent UTIs 1
  • VUR (especially high-grade) 9
• Long-term consequences of renal scarring may include hypertension and chronic kidney disease 2, 3

Antimicrobial Stewardship Considerations

• Increasing antimicrobial resistance is a concern 3
• Avoid treating asymptomatic bacteriuria 5
• Base empiric therapy on local antimicrobial sensitivity patterns 5
• Avoid unnecessary use of broad-spectrum antibiotics 3