Urinary Tract Infection (UTI) – Children

🔍 When to Suspect

A child with urinary symptoms or unexplained fever; symptoms are often non-specific in infants <3 months (e.g., fever, vomiting, poor feeding)

From the full topic in The Ocean Library: Urinary Tract Infection (UTI) – Children

🧭 When to suspect

Suspect a urinary tract infection (UTI) in any child with urinary symptoms or an unexplained fever – it is one of the commonest serious bacterial infections of childhood, and it is easily missed because the presentation is so age-dependent:

• In infants under 3 months, the signs are non-specific: fever, vomiting, poor feeding, lethargy, irritability or prolonged jaundice.

• In children over 3 months, look for dysuria, frequency, urgency, abdominal or loin pain, new daytime wetting, and cloudy or malodorous urine.

E. coli causes the great majority of cases.

Two skills matter most:

• First, an age rule: any baby under 3 months with a suspected UTI needs immediate paediatric referral, with urine sent for urgent microscopy and culture – never a dipstick rule-out.

• Second, separate lower UTI (cystitis) from acute upper UTI (pyelonephritis), because it changes both the antibiotic course length and the threshold for referral.

NICE defines an upper UTI as bacteriuria with a fever of 38°C or higher, or bacteriuria with a fever below 38°C plus loin pain or tenderness.

Lower UTI (cystitis)
• Bacteriuria with no systemic features.
• Dysuria, frequency, urgency, suprapubic or abdominal pain, new daytime wetting, cloudy or offensive urine.

Upper UTI (acute pyelonephritis)
• Bacteriuria plus fever ≥38°C, or fever <38°C with loin pain/tenderness.
• Systemically unwell – high fever, rigors, vomiting, loin pain.

Source: NICE NG224 · NICE NG109 · NICE NG111

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