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febrile child

systematic assessment of fever in children under 5 using the nice traffic light system to identify risk of serious illness — most fevers are viral but must not miss sepsis, meningitis, or kawasaki disease

paediatricscommonacute

About This Page

This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.

The Bottom Line

  • NICE NG143 traffic light system: Green (low risk), Amber (intermediate), Red (high risk)
  • RED flags: pale/mottled/blue skin, unrousable, weak/high-pitched/continuous cry, grunting, RR >60, moderate-severe recession, non-blanching rash, bulging fontanelle, focal neuro signs, bile-stained vomiting
  • Antipyretics for COMFORT if distressed — NOT to prevent febrile seizures, NOT solely to reduce temperature
  • Do NOT use tepid sponging. Do NOT routinely alternate paracetamol and ibuprofen
  • Fever in baby <3 months = high risk — refer urgently. <1 month = full septic screen
  • Fever for 5+ days: think Kawasaki disease

Overview

Fever is one of the most common presenting complaints in paediatrics. The vast majority of febrile illnesses in children under 5 are caused by self-limiting viral infections. However, fever may be the presenting feature of serious bacterial infections including meningitis, pneumonia, UTI, sepsis, or Kawasaki disease. NICE NG143 provides a structured traffic light approach to clinical assessment, guiding investigation and management based on risk stratification.

Epidemiology

Between 20–40% of parents report a febrile illness in their child each year. Fever is the most common reason for a child to see a GP and the second most common reason for hospital admission. The introduction of PCV13, Hib, and MenB/C/ACWY vaccines has significantly reduced invasive bacterial disease. Children under 3 months with fever are at highest risk — approximately 10–15% will have a confirmed bacterial infection.

Clinical Features

Symptoms
Fever — temperature elevated above normal
Coryzal symptoms (runny nose, cough, sore throat) — suggest viral URTI
Poor feeding or reduced fluid intake
Does not wake or stay awake when stimulated
Weak, high-pitched, or continuous cry
Bile-stained vomiting
Reduced urine output
Signs
Normal colour of skin, lips and tongue (GREEN)
Pallor reported by parent (AMBER)
Pale, mottled, ashen, or blue skin (RED)
Non-blanching rash (RED — meningococcal disease)
Tachycardia, tachypnoea, capillary refill >3 seconds
Bulging fontanelle, neck stiffness, focal neuro signs (RED)
Dehydration: dry mucous membranes, reduced skin turgor, sunken eyes

Investigations

First-line
Clinical assessment using traffic light systemMeasure temperature, HR, RR, capillary refill. Assess activity, colour, hydration
Urine sampleAll children with fever and no obvious source — clean catch, dipstick, MC&S
ObservationsPulse oximetry. Use age-appropriate APLS normal ranges
Second-line
BloodsFBC, CRP, blood culture, U&Es, glucose — in AMBER/RED group with no obvious source
CXRIf respiratory symptoms or fever without source in RED group
Lumbar punctureIf meningitis suspected. In <1 month with fever, LP is part of septic screen
Specialist
Further investigationsBased on clinical suspicion: echo if Kawasaki suspected, stool culture, viral PCR panel
1
Traffic light triage
  • GREEN: manage at home with safety netting
  • AMBER: safety net, consider investigations, non-paediatric practitioner should seek advice
  • RED: urgent referral and investigation
2
Antipyretic management
  • Paracetamol or ibuprofen ONLY if child appears distressed
  • Do NOT use to solely reduce temperature
  • Do NOT routinely alternate or combine paracetamol and ibuprofen
  • Do NOT use tepid sponging
  • Antipyretics do NOT prevent febrile seizures
3
Safety netting
  • Advise: regular fluids, do not overdress, keep away from nursery/school
  • Written and verbal advice: when to seek help (not drinking, worsening, non-blanching rash, seizure)
  • Fever >5 days: reassess and consider Kawasaki disease
  • Arrange follow-up or advise to return if no improvement
4
Fever <3 months
  • All babies <3 months with temp 38C+ should be assessed urgently
  • <1 month: full septic screen (blood culture, LP, urine) and empirical antibiotics
  • 1–3 months: assess with caution — low threshold for admission

Complications

  • Febrile seizures: 2–5% of children — manage supportively
  • Dehydration: From poor intake and increased losses
  • Missed serious bacterial infection: Meningitis, UTI, pneumonia, sepsis
  • Kawasaki disease: Consider if fever 5+ days with mucocutaneous features
UKMLA Exam Tips
  • 1Know the NICE NG143 traffic light system: GREEN/AMBER/RED
  • 2Antipyretics are for COMFORT, not to reduce temperature as a goal
  • 3Do NOT use tepid sponging — NICE explicitly recommends against it
  • 4Fever <3 months = always concerning. <1 month = full septic screen and empirical antibiotics
  • 5Fever for 5+ days: think Kawasaki disease
  • 6Non-blanching rash + fever = meningococcal disease until proven otherwise
practicetest your knowledge on febrile childApply what you've learnt with UKMLA-style questions from the iatroX Q-Bank — paediatrics and beyond.
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Verified Sources & References

NICE NG143 — Fever in under 5s