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Urinary Tract Infection (UTI) in Children — Introduction
Urinary tract infection (UTI) (outlink to CDC) is one of the most common serious bacterial infections in childhood and an important cause of fever, morbidity, and potential long-term renal damage. UTIs involve infection of the urinary system, including the bladder (cystitis) and kidneys (pyelonephritis). Early recognition and appropriate management are essential to prevent complications such as renal scarring, hypertension, and chronic kidney disease.
Epidemiology
UTIs occur in approximately 5–8% of girls and 1–2% of boys by 7 years of age. During infancy, UTIs are more common in boys, especially those who are uncircumcised. After the first year of life, girls are affected more frequently due to anatomical and behavioral factors.
Causative Agents
The most common causative organism is Escherichia coli, accounting for the majority of infections. Other pathogens include Klebsiella, Proteus, Enterococcus, and Pseudomonas aeruginosa, particularly in children with structural abnormalities or catheterization. Link to Genitourinary system MCQs
Risk factors and Presentation
Risk factors include vesicoureteral reflux, urinary tract obstruction, neurogenic bladder, constipation, poor perineal hygiene, and dysfunctional voiding. Clinical presentation varies with age: neonates and infants may present with nonspecific signs such as fever, poor feeding, vomiting, or irritability, whereas older children typically present with dysuria, frequency, urgency, abdominal pain, or flank pain.
Prevention
Because recurrent infections increase the risk of renal scarring, identifying children at risk and initiating preventive strategies — including behavioral measures and, when indicated, antibiotic prophylaxis — is an important component of pediatric care.
UTI Prophylaxis in Children
| Drug | Dose (once daily unless stated) | Age suitability | When preferred | Important notes |
|---|---|---|---|---|
| Nitrofurantoin | 1–2 mg/kg at bedtime | >1 month | First-line prophylaxis | Avoid if G6PD deficiency; may cause nausea |
| Trimethoprim-Sulfamethoxazole (TMP-SMX) | 2 mg/kg (TMP component) | >2 months | Common first choice | Avoid in neonates; risk of Stevens-Johnson syndrome |
| Trimethoprim alone | 2 mg/kg | >2 months | Alternative to TMP-SMX | Useful if sulfa allergy |
| Cephalexin | 10–12 mg/kg | All ages | Infants & vesicoureteral reflux | Good safety profile |
| Amoxicillin | 10–15 mg/kg | <2 months | Neonatal prophylaxis | Resistance common after infancy |
| Cefixime | 2 mg/kg | >6 months | Resistant organisms | Used less commonly |
Indications for UTI Prophylaxis
- Vesicoureteral reflux (Grade III–V)
- Recurrent febrile UTIs (≥2 in 6 months or ≥3/year)
- Obstructive uropathy awaiting surgery
- Neurogenic bladder
- After first febrile UTI in infants until evaluation complete
Duration
- Continue until:
- VUR resolves or is surgically corrected
- Child becomes toilet trained and infection-free
- Specialist review recommends stopping
Key Clinical Points
✔ Give at bedtime for maximal bladder concentration
✔ Encourage hydration & regular voiding
✔ Treat constipation (important risk factor)
✔ Monitor for breakthrough infections and resistance
Treatment of UTI in Children
Empirical Antibiotic Therapy (Based on Clinical Type)
| Clinical Type | Oral Antibiotics (Outpatient) | IV Antibiotics (Inpatient / Severe) | Duration |
|---|---|---|---|
| Simple cystitis (Afebrile UTI) | Nitrofurantoin 5–7 mg/kg/day ÷ 2 doses Cephalexin 50–100 mg/kg/day ÷ 3–4 doses TMP-SMX 8–10 mg/kg/day (TMP component) ÷ 2 doses | Usually not required | 5–7 days |
| Febrile UTI / Acute pyelonephritis | Cefixime 8 mg/kg/day OD Amoxicillin-clavulanate 40–50 mg/kg/day ÷ 2–3 doses | Ceftriaxone 50–75 mg/kg OD Cefotaxime 150 mg/kg/day ÷ 3 doses Gentamicin 5–7 mg/kg OD | 7–14 days |
| Neonatal UTI (<2 months) | Not preferred | Ampicillin + Gentamicin OR Cefotaxime | 10–14 days |
| Complicated UTI / Toxic child | Not preferred | Ceftriaxone ± Amikacin Consider Piperacillin-Tazobactam if resistant | 10–14 days |
Organism-Specific Considerations
| Organism | Preferred Drugs |
|---|---|
| Escherichia coli | Cephalosporins, Nitrofurantoin, TMP-SMX (if sensitive) |
| Proteus | Avoid Nitrofurantoin; use cephalosporins |
| Pseudomonas aeruginosa | Ceftazidime, Piperacillin-Tazobactam |
| Enterococcus | Ampicillin, Amoxicillin |
Supportive Management
| Measure | Details |
|---|---|
| Hydration | Encourage oral fluids |
| Antipyretics | Paracetamol / Ibuprofen |
| Treat constipation | Important to prevent recurrence |
| Follow-up culture | If no improvement in 48 hours |
| Imaging | RBUS after first febrile UTI (especially <2 years) |
Important Clinical Points
✔ Send urine routine + culture before starting antibiotics
✔ Switch from IV to oral once clinically improved (24–48 hrs)
✔ Modify antibiotics according to culture sensitivity
✔ Admit if: toxic appearance, persistent vomiting, dehydration, neonate, poor follow-up
