The febrile child
Your mission: find the source — and make sure it isn't one of the killers. Spotting the seriously ill child, using the NICE traffic-light system, investigating by age and risk, and sending the rest home safely. Built for revision, not live patient decisions.
Settle them, and check the basics
look before you touchRed flags — what each should make you think
Watch the child from the doorway before you call their name. Running round the play area with a toy, or floppy and glued to a parent? Activity and interaction tell you a lot. But young babies — especially under 3 months — can be seriously ill and look deceptively quiet, so have a low threshold for them.
If the child looks sick — act as you assess (paediatric Sepsis Six)
- O₂High-flow oxygenaim SpO₂ above 94%
- IVIV or IO access, bloodsgas + lactate, glucose (treat hypoglycaemia), FBC, U&E, CRP, blood cultures
- ℞IV / IO antibioticswithin the hour — ceftriaxone; add amoxicillin if under 3 months (Listeria)
- flConsider fluid resuscitationcrystalloid bolus 10 mL/kg, reassess after each — older textbooks quote 20 mL/kg; follow current NICE and local guidance
- inoConsider inotropes earlyif not responding to around 40–60 mL/kg
- ☎Involve seniors and PICU earlysenior ED, senior paediatrician, critical care / retrieval
Understand the child — history, examination, risk
the traffic lightMeasure the temperature properly
- Under 4 weeks — electronic thermometer in the axilla
- 4 weeks to 5 years — electronic or chemical-dot axillary thermometer, or infrared tympanic
- Don't use forehead strips (unreliable), or oral / rectal routes in the under-5s
- A parent's reported fever counts — take it seriously even if the child is normothermic now
Fever is usually defined as 38°C or above. Beyond the under-6-month thresholds, the height of the fever doesn't tell you how sick the child is. High temperatures (40–42°C) don't damage tissue and don't predict febrile seizures. Look at the trend and the child, not the number.
The history — what to ask
- The fever — onset, duration, daily peaks, any fever-free gap (matters most past 5 days), temperatures recorded at home
- Behaviour — lethargy, off feeds; does it improve when the fever settles? Rigors? Febrile seizures?
- Antipyretics — which, what dose, and the time of the last dose
- Focal symptoms — cough, ear pulling, sore throat or refusing food (look in the mouth), vomiting, diarrhoea, dysuria, smelly urine, limp
- Rash — when it appeared relative to the fever, where it started, how it spread
- Hydration — oral intake, wet nappies / urine output
- Vaccinations — are they up to date?
- Birth history in young babies — preterm, NICU stay, maternal GBS or a previous baby with invasive GBS, prolonged rupture of membranes, perinatal antibiotics
- PMH — recurrent infections, immunocompromise, congenital heart or renal disease
- Contacts and exposures — sick contacts, foreign travel, suspicious food, school outbreaks. Are there vulnerable contacts at home (pregnant, newborn, immunocompromised)?
- Parental concern — ask what they're worried about. "Fever phobia" is common, and naming the fear lets you reassure them directly.
Work A–E — assess and act as you go
The NICE traffic-light system (under-5s)
Grade every child. One feature in a column puts them in that column. It guides investigation and disposition when there's no clear diagnosis.
green — low risk
- Normal colour
- Responds normally, content, smiles
- Stays awake or wakes quickly
- Strong normal cry, or not crying
- Normal skin and eyes, moist mucous membranes
- No amber or red features
amber — intermediate
- Pallor reported by parent
- Not responding normally, no smile, wakes only with prolonged stimulation, less active
- Nasal flaring; RR >50 (6–12 m) or >40 (>12 m); SpO₂ ≤95% in air; crackles
- HR >160 (<12 m), >150 (12–24 m), >140 (2–5 y)
- CRT ≥3 s, dry mucous membranes, poor feeding, reduced urine
- Age 3–6 months with temp ≥39°C
- Fever ≥5 days, rigors
- Swollen limb or joint, not weight-bearing
red — high risk
- Pale, mottled, ashen or blue
- No response to social cues, looks ill to a clinician
- Doesn't wake, or won't stay awake
- Weak, high-pitched or continuous cry
- Grunting, RR >60, moderate–severe recession
- Reduced skin turgor
- Age under 3 months with temp ≥38°C
- Non-blanching rash, bulging fontanelle, neck stiffness
- Status epilepticus, focal neurology, focal seizures
The killers you must not miss
tap to open eachWhat points toward it, what would rule it in, and how to manage it.
A petechial or purpuric rash that doesn't blanch, especially spreading, with an unwell child. Early on the rash can be macular and blanching, and some children have no rash at all. Look for leg pain, cold hands and feet, and abnormal skin colour too.
A clinical diagnosis. Don't wait for bloods or PCR. A well child with a few petechiae above the nipple line after coughing or vomiting may be observed with senior input and bloods.
Parenteral antibiotics immediately: IV ceftriaxone in hospital (benzylpenicillin IM/IV in primary care before transfer). Resuscitate with fluid, call senior and PICU early. Notify public health, who arrange prophylaxis for contacts.
Drowsiness or reduced consciousness, irritability, bulging fontanelle, neck stiffness (often absent in infants), seizures. Focal fits or focal neurology suggest HSV encephalitis.
Lumbar puncture (if no contraindication: reduced or fluctuating GCS, focal signs, shock, coagulopathy, recent seizure). Don't delay antibiotics for the LP.
IV ceftriaxone (plus amoxicillin under 3 months). Add IV aciclovir if drowsy, encephalopathic or with focal signs or seizures. Dexamethasone per local and NICE guidance when bacterial meningitis is likely. Senior and PICU early.
Any red feature: tachycardia, tachypnoea, CRT ≥3 s, mottled or cold skin, reduced consciousness, reduced urine output. Hypotension is a late, pre-arrest sign in children. Children compensate until they suddenly don't.
A clinical picture supported by gas and lactate. Use your trust's age-specific sepsis tool or PEWS.
Paediatric Sepsis Six (stage 1): antibiotics within the hour, fluid bolus with reassessment after each, early inotropes if fluid-refractory, PICU and retrieval team.
Any baby under 3 months with a temperature of 38°C or more. They can look well and still have bacteraemia, UTI or meningitis (GBS, E. coli, Listeria).
Septic screen: FBC, CRP, blood cultures, urine, plus stool culture if diarrhoea and a CXR only if respiratory signs. LP in all under 1 month, in unwell infants aged 1–3 months, and in those aged 1–3 months with WBC <5 or >15 ×10⁹/L.
Parenteral antibiotics for under 1 month, and for 1–3 months if unwell or WBC abnormal: cefotaxime / ceftriaxone plus amoxicillin for Listeria (neonatal units may use local regimens). Low threshold to admit.
Fever for 5 days or more plus: bilateral non-purulent conjunctivitis; red cracked lips or strawberry tongue; swollen red hands and feet (peeling later); polymorphous rash; cervical lymphadenopathy. Often a very miserable child.
Clinical, supported by bloods (high CRP / ESR, anaemia, later thrombocytosis, low albumin, sterile pyuria) and echocardiogram. Infants under 1 year often have incomplete features but the highest coronary risk.
Refer to paediatrics the same day. IV immunoglobulin and aspirin under specialist care; IVIG within 10 days of fever onset protects the coronary arteries. Echo follow-up for coronary aneurysm.
Fever with a swollen or hot joint, a limp, refusing to weight-bear, or a baby not moving a limb (pseudoparalysis). Both are amber features.
Bloods (WCC, CRP, ESR, cultures), ultrasound for effusion, joint aspiration. Kocher criteria can help separate it from transient synovitis.
Urgent orthopaedic and paediatric referral, joint washout, IV antibiotics after cultures.
A child with scarlet fever, chickenpox or a skin infection who becomes much more unwell: erythroderma, shock, severe limb pain, empyema or a spreading soft-tissue infection.
Clinical, with blood cultures and throat or skin swabs.
Sepsis pathway, IV antibiotics per local iGAS policy (often with clindamycin for toxin), early senior and PICU, surgical review for any necrotising infection. Notify public health.
Don't forget the mimics
Not every hot, drowsy child is infected. In older children consider illicit drugs (MDMA, amphetamines, ketamine) and other toxins. Also think of intussusception (lethargy, vomiting, colicky pain, redcurrant-jelly stool), DKA, and malaria in anyone back from an endemic area.
Find the source — reaching a diagnosis step by step
the algorithm- 1Is the child seriously ill?Any red feature or a positive sepsis screen → resuscitate and treat now (stages 1 & 3). Diagnosis comes second.
- 2Is the child under 3 months?Yes → treat as high risk whatever they look like: septic screen, ± LP, ± antibiotics, admit.
- 3Is there a non-blanching rash?Yes → meningococcal disease until proven otherwise.
- 4Has the fever lasted 5 days or more?Yes → screen for Kawasaki features. If none, discuss with paediatrics as a prolonged fever / PUO.
- 5Is there a clear focus?Ears, throat, chest, urine, gut, skin, joints → treat that source (table below). If you find a source, you often need no further tests.
- 6No focus found?Investigate by traffic light (stage 5). Always test the urine. Re-examine after antipyretics; how the child looks then matters more than the temperature.
The common sources — what points to each, and what to do
URTI / viral illness
Acute otitis media
Tonsillitis / pharyngitis
Scarlet fever
UTI / pyelonephritis
Bronchiolitis
Pneumonia
Gastroenteritis
Viral exanthems
Think laterally. A child refusing food may have the source in their mouth (stomatitis, tonsils). A febrile child who won't walk may have a hip, not a "virus". And always ask: what am I treating, and for whom? Parents' expectations alone are not an indication for antibiotics.
Investigate — by age and traffic light
indicated, not routineUnder 3 months
Red features, no source
Amber features, no source
Green features, no source
Bedside glucose
Specific tests
Don't be falsely reassured
A fall (or no fall) in temperature after paracetamol or ibuprofen doesn't separate serious from minor illness. What matters is how the child looks once comfortable: a bouncing, feeding, interactive child with a normal heart rate is reassuring. If the source is still unclear after basic tests, even in a well child, discuss with the paediatric team. Observation for a few hours is a perfectly good investigation.
How the plan comes together
disposition · safety netgreen → home
Source found or well with no red or amber features. Discharge with advice.
Safety-net: what to expect, how long it lasts, when to come back.
amber → think
No diagnosis but amber features: consider discharge only with a clear safety-net plan (written advice, review arrangements, direct access back), or admit / observe.
Factor in age, social circumstances, parental concern and the time of day.
red → admit
Any red feature, under 3 months with fever, or an unusual or non-blanching rash. Refer to paediatrics; PICU if critically unwell.
Hand over: traffic-light features, antibiotic times, fluid given, LP done or deferred.
Antipyretics — for distress, not the number
- Use paracetamol or ibuprofen only if the child is distressed; don't treat the temperature for its own sake
- Continue only while distressed; switch to the other agent if the first doesn't help
- Don't give both together; alternate only if distress returns before the next dose is due
- Antipyretics don't prevent febrile seizures
- No tepid sponging; don't under-dress or over-wrap
- Explain to parents that fever is a normal response to infection and is rarely harmful in itself
Safety-netting — tell parents to come back if…
- The child has a fit
- A rash appears that doesn't fade under a glass
- The child becomes harder to wake, floppy, or has a weak or high-pitched cry
- Breathing becomes fast or hard work, or there's grunting
- Signs of dehydration: no wet nappy for 12 hours, dry mouth, sunken eyes or fontanelle, not drinking
- The fever lasts 5 days or more
- They're more worried than before, or simply can't cope
Encourage regular fluids, check on the child during the night, and keep them off nursery or school while febrile.
What you see now may not be how the child looks in six hours. "Just a virus" can still make a well child decompensate. So the safety net isn't an afterthought — it's part of the treatment. Nicely done getting here.
Clerking template
copy or downloadThe febrile child — documentation structure
A structure and prompt list to help you document and think systematically. It is not a completeness check and cannot guarantee nothing is missed — use your trust's own proforma, your seniors, and your clinical judgement. Content is AI-generated and not yet fully reviewed.