Reasoning GP · Algorithm · 1-page summary
Fever in children (0–12 years)
For: children with fever in primary care; the NICE traffic-light table is validated under 5, same principles to 12. Not for: adults (use the fever in adults algorithm); immunocompromised children follow their specialist fever or neutropenic sepsis pathway.
Core rule: the height of the fever and its response to antipyretics do not tell you who is seriously ill. Judge colour, activity, breathing, circulation, hydration and age; any infant under 3 months with ≥38°C is red; trust parental concern.
0Stop — call 999 now — only essential treatment that does not delay transfer (airway, oxygen, glucose, monitoring)
- New non-blanching petechial or purpuric rash, suspected meningitis or bulging fontanelle → 999. Meningococcal disease strongly suspected → IV/IM ceftriaxone (preferred) or benzylpenicillin unless it delays transfer.
- Shock: mottled, pale, ashen or blue skin, weak pulses, hypotension, altered mental state → 999. Capillary refill ≥3 s alone is amber.
- Reduced consciousness: GCS drop, not rousable or does not stay awake, weak, high-pitched or continuous cry; seizure ≥5 min or breathing compromised → 999
- Respiratory compromise: SpO₂ <92% in air, cyanosis, grunting, severe chest indrawing, apnoea, exhaustion → 999; oxygen if shock or SpO₂ <92%.
1Triage by age — age is the first risk modifier
| Age | Action |
|---|---|
| <3 months | ≥38°C = red → urgent paediatric (hospital) assessment, generally ≤2 h, even if well; 999 if block 0 features |
| 3–6 months | ≥39°C = amber → face-to-face; consider same-day paediatric review |
| 6 months–5 y | Viral most likely; traffic-light features, not temperature height |
| 5–12 years | Same principles (table not validated); local paediatric and sepsis pathways |
2Screen — one row is enough
- Other NICE red: no response to social cues, appears ill to you, RR >60, moderate chest indrawing, reduced skin turgor, focal neurology or focal seizure → Urgent ≤2 h. Also urgent (judgement, not NICE table): not tolerating fluids; surgical abdomen
- Immunocompromised (chemotherapy, neutropenia, central line, asplenia, transplant) → specialist advice, usually Same-day hospital
- Amber: pallor, less active, nasal flaring, SpO₂ ≤95% in air, capillary refill ≥3 s, rigors → face-to-face; Same-day paeds per clinical picture
- Fever ≥5 days with suspected Kawasaki (incl. incomplete; do not wait for 4–5 criteria); limb swelling and refusal to weight-bear → Same-day paeds
- Leukaemia: pallor, persistent fatigue, unexplained fever, persistent infection, generalised nodes, bone pain, bruising, bleeding → FBC ≤48 h; unexplained petechiae or hepatosplenomegaly → Immediate paeds
3Assess — full examination every time
☐ Axillary temperature (or tympanic 4 weeks–5 years) ☐ RR (amber >50 at 6–12 months, >40 over 1 year), HR, capillary refill, SpO₂ ☐ Undress: whole skin, nappy area, conjunctivae ☐ Hydration, fontanelle, ears, throat, chest, abdomen, joints ☐ Urine if UTI suspected or no clear source
No blood cultures or LP in primary care; no routine FBC, CRP or CXR in a well child with a clear viral illness.
4Classify — only if the screen is negative
- Green, viral — normal colour, response and cry, moist mucous membranes, clear viral source → home with safety-net.
- Bacterial focus — otitis media, tonsillitis, pneumonia, UTI (often no localising symptoms in infants) → treat the focus.
- Kawasaki — fever ≥5 days with conjunctival injection, oral mucosal or hand/foot changes, rash, cervical nodes; features may have resolved.
- Febrile seizure — simple and back to baseline: no routine EEG or imaging. Focal, complex, meningism or recurrence within 24 h → urgent paediatrics.
- Uncertain or no focus — higher risk of serious infection; say so, test urine, reassess.
5Treat today — doses: NICE/SPC, BNFC, local formulary
- Distress only: paracetamol or ibuprofen (≥3 months and ≥5 kg; not if dehydrated, renal impairment or chickenpox). Never together; alternate only if distress recurs before the next dose.
- Otitis media: most none or delayed; amoxicillin 5–7 days. Sore throat: FeverPAIN/Centor; phenoxymethylpenicillin 5–10 days. None for viral URTI.
- UTI ≥3 months: lower, trimethoprim or nitrofurantoin 3 days; upper, cefalexin 7–10 days. Non-severe pneumonia (3 months–11 years): amoxicillin 3 days. Check local guidance.
6Refer routinely and follow up
- Parental concern overriding your assessment, not improving, new symptoms or unable to assess adequately → Urgent GP / OOH face-to-face reassessment; look for a new focus.
- Renal ultrasound within 6 weeks: first UTI responding to treatment under 6 months, or recurrent UTI; atypical UTI → during the infection.
- Febrile seizure, diagnosis uncertain or atypical → specialist assessment.
7Never reassure by
- A lower temperature, or a fall after paracetamol or ibuprofen.
- A normal FBC or CRP: neither rules out serious infection.
- No neck stiffness or no rash: meningitis and meningococcal disease can occur without them.
- A well-appearing infant under 3 months with ≥38°C.
- An obvious viral focus in a child who stays unwell: test urine for a concurrent UTI.
- Recent vaccination, if symptoms are persistent, severe or unusual.
8Safety-net — say it, give it in writing, document it
999 “Call 999 if a rash appears that does not fade or a rash changes, your child has a fit, is less responsive, very sleepy or hard to wake, has a weak, high-pitched or constant cry, a stiff neck, dislikes light, has a bulging soft spot, finds breathing hard, fast or noisy, or is pale, mottled, blue or cold.”
Same day “Contact us today if they cannot keep fluids down or pass much less urine, the fever lasts 5 days or more, a limb or joint swells, they will not bear weight or have severe pain, symptoms are new or worse, or you are more worried.” No aspirin under 16.
✓Safe to leave primary care only if — all five, documented
No block 0–2 row applies; age over 3 months
Temp, RR, HR, capillary refill, SpO₂ and traffic-light colour recorded
Source named, or no source stated; urine tested if indicated
Drinking adequately; parent confident with the plan
Written safety-net given; review or referral owner set
Summary of the full Reasoning GP fever in children algorithm, which holds the detail, examination, investigations, antibiotic choices and evidence. Sources: NICE NG143, NG254, NG240, NG224, NG12 (updated April 2026), NG109, NG111, NG91, NG84, NG217, NG250; UKHSA. Clinical reference — follow local pathways; check doses in the SPC and local formulary.