Why Paediatric Fever Is Examined
Fever is the most common reason for children to present to emergency departments and is a leading cause of paediatric OSCE stations. The NICE traffic light system (CG160) is the standard framework for all UK trainees and is universally examined. Examiners test systematic assessment, vital sign thresholds, identification of red flag features (meningococcal disease, serious bacterial infection), and safe management including when to admit and when to treat.
⚠️ Red Flag
Any child under 3 months with a temperature above 38 degrees C should be urgently assessed and admitted — their immune system is immature and bacterial infection can deteriorate rapidly with few warning signs.
Age-Appropriate Vital Sign Thresholds
Normal vital signs vary markedly with age — using adult thresholds in children is a critical error:
| Age | Heart rate (normal) | Respiratory rate (normal) | SBP (normal) |
|---|---|---|---|
| Under 1 year | 110-160 bpm | 30-40/min | 70-90 mmHg |
| 1-2 years | 100-150 bpm | 25-35/min | 80-95 mmHg |
| 2-5 years | 95-140 bpm | 25-30/min | 80-100 mmHg |
| 5-12 years | 80-120 bpm | 20-25/min | 90-110 mmHg |
| Over 12 years | 60-100 bpm | 15-20/min | 100-120 mmHg |
NICE Traffic Light System (CG160 2013, Updated 2021)
Green — Low Risk (Observe)
- Normal colour (skin, lips, tongue)
- Responds normally to social cues; content/smiling
- Stays awake or awakens quickly; strong normal cry
- Moist mucous membranes
- Normal skin turgor
Amber — Intermediate Risk (Urgent Assessment)
- Pallor reported by parent/carer
- Not responding normally; no smile
- Wakes only with prolonged stimulation
- Dry mucous membranes; poor feeding (infants); reduced urine output
- Rigors
- Fever for more than 5 days
- Swelling of a limb or joint; non-weight bearing
- New lump over 2 cm
Red — High Risk (Emergency — admit same day)
- Pale/mottled/ashen/blue colour
- No response to social cues; appears ill to a healthcare professional
- Unable to rouse or stays awake only if stimulated
- Weak, high-pitched, continuous cry
- Grunting
- Tachypnoea: over 60/min under 5; over 40/min aged 5-12
- Moderate or severe chest indrawing
- Reduced skin turgor (dehydration)
- Non-blanching rash
- Bulging fontanelle (under 18 months)
- Neck stiffness
- Seizure with fever (prolonged or focal)
Non-Blanching Rash — Meningococcal Disease
⚠️ Red Flag
A non-blanching rash in a febrile child is meningococcal disease until proven otherwise. Do the glass test: press firmly — if the rash does not blanch, administer IM benzylpenicillin (or IV ceftriaxone if available) immediately, then call 999. Do not wait for blood results or LP. Time to antibiotic administration is the most important determinant of outcome.
IM Benzylpenicillin doses:
- Under 1 year: 300 mg
- 1-9 years: 600 mg
- 10 years and above: 1200 mg
Fever Assessment — Focused History
Duration: How long has the child been unwell? Fever over 5 days = Kawasaki disease, occult serious infection, or malignancy until proven otherwise.
Source of infection:
- Upper respiratory: runny nose, sore throat, earache, cough
- Lower respiratory: fast breathing, chest indrawing, wheeze
- Urinary: crying on urination, smelly urine (UTI — most common serious bacterial infection in young children)
- CNS: neck stiffness, photophobia, bulging fontanelle, altered consciousness
- Skin/bones: redness, swelling, warmth, refusal to use a limb
Immunisation history: unimmunised children at higher risk of Hib, meningococcal C, pneumococcal disease.
Exposure history: contacts with meningitis, TB, chickenpox.
Management by Traffic Light Category
Green — low risk
- Advise parents on home management
- Paracetamol or ibuprofen for fever-related distress (see below)
- Safety netting: return if rash, child becomes harder to wake, child seems sicker
- No antibiotics unless source identified
Amber — intermediate risk
- Urgent assessment; investigations depending on clinical picture
- Full blood count, CRP, blood cultures, urine MC&S
- Consider LP if meningism features without CI
- Oral antibiotics if source identified; admit if uncertain
Red — high risk
- Immediate paediatric assessment; resuscitation team alert
- IV/IO access; blood cultures, FBC, CRP, blood gas, glucose, U&E
- IV antibiotics immediately (ceftriaxone 80 mg/kg OD — max 4 g)
- IV fluid 10 mL/kg bolus if signs of shock; reassess
Antipyretic Management
Indications for antipyretics: distress, discomfort, or child appears unwell due to fever — not to "prevent febrile convulsions" (evidence does not support this).
| Drug | Age | Dose | Frequency |
|---|---|---|---|
| Paracetamol | 2 months and above | 15 mg/kg | Every 4-6 hours; max 4 doses/24 hours |
| Ibuprofen | 3 months and above (over 5 kg) | 5-10 mg/kg | Every 6-8 hours with food |
Alternating paracetamol and ibuprofen is not routinely recommended by NICE (limited evidence) but may be used for prolonged fever distress under medical advice.
Frequently Asked Questions
"What is the most common serious bacterial infection in children under 2 years?"
Urinary tract infection. It accounts for up to 5-7% of febrile infants under 2 years and is easily missed because urinary symptoms may be absent. Urine should be tested in all children under 2 years with unexplained fever lasting more than 24 hours, using a clean catch specimen (not a bag specimen — high contamination rate) or catheter sample in infants. Dipstick is a useful initial screen; confirm with MC&S.
"What is Kawasaki disease and when should it be suspected?"
Kawasaki disease is a medium-vessel vasculitis affecting children under 5 years, of unknown aetiology. It is the leading cause of acquired heart disease in children in high-income countries (coronary artery aneurysms in 25% if untreated). Suspect when fever lasts 5 or more days plus at least 4 of: conjunctival injection (non-purulent), strawberry tongue/cracked lips, cervical lymphadenopathy, polymorphic rash, changes to hands/feet (oedema, desquamation). Treatment: IV immunoglobulin (IVIG) + aspirin reduces aneurysm risk by 80%.
"What is a febrile convulsion and how is it managed?"
A febrile convulsion is a seizure triggered by rapid rise in temperature (above 38 degrees C) in a child aged 6 months to 6 years without another CNS cause. Simple febrile convulsions: generalised, last under 15 minutes, no recurrence within 24 hours, child returns to normal. Manage: airway, lateral position, time the seizure, give rectal diazepam or buccal midazolam if lasting over 5 minutes. Reassure parents — febrile convulsions do not cause brain damage and the majority do not recur. Refer if complex (focal, prolonged, multiple within 24 hours) or if meningitis cannot be excluded.
"When should you perform a lumbar puncture in a febrile child?"
LP is indicated when bacterial meningitis is suspected and contraindications are absent. Do not perform LP if: child is shocked or haemodynamically unstable, there is a purpuric rash (meningococcal disease — give antibiotics immediately without LP), GCS below 12 or falling, focal neurology, or raised ICP (bulging fontanelle without crying, papilloedema). In these cases, give antibiotics immediately, stabilise, then consider LP later.
"What is the difference between a simple and complex febrile convulsion?"
Simple febrile convulsion: generalised tonic-clonic, duration under 15 minutes, no recurrence within 24 hours, full recovery within 1 hour, no prior neurological abnormality. Complex febrile convulsion: focal onset, duration above 15 minutes (febrile status epilepticus), more than one seizure in 24 hours, or post-ictal focal neurology (Todd's paresis). Complex febrile convulsions require investigation (EEG, MRI, LP), are associated with higher risk of subsequent epilepsy, and warrant paediatric neurology review.
Related Posts
- Paediatric History Taking OSCE — systematic history for the unwell child
- Paediatric Examination OSCE — examining the febrile child
- Meningitis OSCE — recognising and managing bacterial meningitis including in children