Oral temperature ≥38.0 °C (100.4 °F); evaluate for infective vs non-infective causes by duration and pattern.
History taking
- • Onset, duration, pattern (continuous, remittent, intermittent), maximum recorded temperature
- • Associated symptoms: chills/rigors, sweats, headache, cough, dysuria, diarrhoea, rash, joint pain
- • Travel, contacts (TB, COVID), animal exposure, mosquito bites, recent surgery/IV lines
- • Drug history (antipyretics taken), comorbidities, immunosuppression, HIV status
Examination
- • Vitals: temperature, HR, BP, RR, SpO₂; look for sepsis (qSOFA)
- • Skin: rash, petechiae, eschar; LN: cervical/axillary/inguinal lymphadenopathy
- • Throat, ears, sinuses, chest, abdomen (hepatosplenomegaly), CVS, CNS (neck stiffness)
- • Pus pockets — teeth, perineum, IV sites, decubitus areas
Red flags
- • Hypotension, RR>30, altered sensorium, SpO₂<92%
- • Petechial/purpuric rash, neck stiffness
- • Fever >7 days without focus, immunocompromised host
- • Recent travel from malaria/Ebola-endemic area
Differential diagnosis
- • Viral fever, influenza, dengue, malaria, typhoid, chikungunya
- • Bacterial: UTI, pneumonia, cellulitis, enteric fever, meningitis
- • TB, abscess, infective endocarditis
- • Non-infective: drug fever, malignancy, autoimmune (SLE, vasculitis), thyrotoxicosis
Recommended investigations
- • CBC with peripheral smear, ESR/CRP
- • Urinalysis & culture, blood culture x2 if toxic/febrile >5 d
- • Malaria RDT + smear, dengue NS1/IgM (day-wise), Widal/typhidot
- • LFT, RFT, electrolytes; chest X-ray; targeted serologies
Diagnosis
- • Combine clinical pattern + focal signs + key investigations
- • Label as PUO if >3 weeks fever, ≥3 OPD visits or 3 days inpatient without diagnosis
Initial treatment / management
- • Antipyretic: Paracetamol 500–1000 mg PO 6–8 hourly (max 4 g/day)
- • Oral fluids 2.5–3 L/day; tepid sponging if T>39.5 °C
- • Treat focus: empirical antibiotic only if clear bacterial focus or sepsis
- • Admit if hypotensive, hypoxic, encephalopathic, bleeding, or platelets <30k
Prescription examples
- • Tab Paracetamol 650 mg — 1 tab PO TDS x 3 d (PRN fever)
- • Tab ORS sachet — in 1 L water, sip throughout day
- • If presumed bacterial UTI: Tab Nitrofurantoin 100 mg PO BD x 5 d
- • If malaria (P. vivax confirmed): Tab Chloroquine + Primaquine as per NVBDCP
Follow-up advice
- • Review in 48–72 h or earlier if red flag emerges
- • Repeat CBC + platelets in dengue endemic season daily until afebrile 48 h
- • Document defervescence and resolution of focus
Patient counselling
- • Adequate oral hydration and rest; avoid self-medication with antibiotics
- • Warning signs to return immediately: bleeding, breathlessness, drowsiness, persistent vomiting
- • Mosquito precautions in endemic areas (nets, repellents)
Referral criteria
- • Sepsis, persistent fever >7 d without focus, suspected meningitis/endocarditis
- • Pregnant patient with high-grade fever
- • Immunocompromised or post-transplant patient
Clinical pearls
- • Always recheck pulse-temperature dissociation (relative bradycardia → typhoid, drug fever)
- • In dengue, falling platelet + rising haematocrit signals plasma leak
- • Rule out malaria with smear AND RDT in endemic zones — single negative does not exclude
References
- • Harrison's Principles of Internal Medicine, 21e — Fever and PUO
- • WHO Dengue Guidelines 2009
- • NVBDCP National Drug Policy on Malaria (India)
Educational outpatient guide — verify against local guidelines before clinical use.
