AdultPediatric
Fever is rectal T ≥ 38.0 °C (100.4 °F). Workup is driven by age. Neonates (< 28 d) get full sepsis evaluation regardless of appearance. 29–60 d use AAP 2021 / Step-by-Step / PECARN. ≥ 60 d are managed by appearance and source.
🚩 Red-flag clues (must not miss)
- •Any neonate (< 28 d) with fever = full sepsis workup + empiric abx + admit
- •Petechiae below the nipple line + fever = meningococcemia
- •Toxic appearance (Yale Observation Score elevated) at any age
- •Fever + bulging fontanelle, paradoxical irritability = meningitis
- •Fever > 5 days + conjunctivitis + rash + extremity changes = Kawasaki
History
- Duration, max temp, antipyretic response
- Vaccinations (Hib, PCV13, MenACWY)
- Sick contacts, travel, daycare
- Recent antibiotics (partially treated meningitis)
Exam
- PAT — appearance is the most predictive single feature
- Skin: petechiae, purpura, rash, mucous membranes
- Anterior fontanelle, neck supple, ears, oropharynx
- Joint exam (septic arthritis), bone (osteo)
Labs
- < 28 d: CBC + diff, blood cx, UA + urine cx, LP (cell count, gluc, protein, cx, HSV PCR), procalcitonin if available, RVP
- 29–60 d (low risk by Step-by-Step / AAP): UA + urine cx; consider blood cx, procalcitonin, CRP
- ≥ 60 d: source-directed (UA if no source < 24 mo)
Imaging
- CXR if respiratory signs or WBC > 20 K without source
- US/CT for occult source if persistent
Differential & next step
| Diagnosis | Clue | Next step |
|---|---|---|
| Viral URI (most common) | Rhinorrhea, cough, well | Symptomatic; return precautions |
| UTI | Fever without source, esp. girls < 24 mo, uncirc boys < 12 mo | Cath UA + cx; PO cefdinir if low risk, IV ceftriaxone if ill |
| Otitis media | Bulging TM with effusion | Amox 80–90 mg/kg/d if treating |
| Pneumonia (CAP) | Tachypnea, focal crackles, hypoxia | Amoxicillin high dose; admit if hypoxic |
| Bacteremia / occult | Toxic with WBC > 15 K | Blood cx, IV ceftriaxone, admit |
| Meningitis | Bulging font, nuchal, AMS | LP; ceftriaxone + vanc + dex; +acyclovir if neonate/HSV |
| Kawasaki disease | Fever ≥ 5 d + 4 of 5 criteria | Echo, IVIG 2 g/kg + ASA |
| Multisystem inflammatory syndrome (MIS-C) | Persistent fever + multi-organ + recent COVID | Echo, troponin, IVIG/steroids |
Medications & dosing
| Drug | Dose | Notes |
|---|---|---|
| Acetaminophen | 15 mg/kg PO/PR q4–6h (max 75 mg/kg/24h) | Avoid in neonate < 1 mo without consult |
| Ibuprofen | 10 mg/kg PO q6–8h (max 40 mg/kg/24h) | Avoid < 6 mo, dehydration, renal disease |
| Ceftriaxone (sepsis ≥ 1 mo) | 50 mg/kg IV (75–100 if meningitis, max 4 g) | Avoid in neonates (hyperbili / Ca-IVF) |
| Ampicillin (neonate) | 50 mg/kg IV q6–8h (meningitis 100 mg/kg q6h) | |
| Gentamicin (neonate) | 4 mg/kg IV q24h (term) | Adjust per gestational age |
| Cefotaxime (neonate) | 50 mg/kg IV q6–8h | |
| Acyclovir | 20 mg/kg IV q8h | Add if HSV risk (vesicles, maternal HSV, seizure) |
Management / next steps
- < 28 d: CBC, blood cx, UA/cx, LP → admit on amp + gent (+/− acyclovir)
- 29–60 d: risk-stratify (AAP 2021); low-risk → observation, high-risk → admit on ceftriaxone (+amp)
- ≥ 60 d well: source-directed
- Empiric antibiotics within 1 h if sepsis suspected
Source: https://fprmed.com/fprmedcom/Pages/Pedi/Pedi_Fever.html
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