Fever in Adults: A Rational Diagnostic Pathway

Prof. Dr. H.M.P. Singh

Introduction

Fever is a common presenting problem with a broad differential. Over-investigation increases cost without improving outcomes — a structured approach balances thoroughness and pragmatism.

Framework

1. Is the patient unstable? If yes → immediate resuscitation and broad-spectrum empiric antibiotics if sepsis suspected.

2. History and exposure: Travel, animal contacts, occupational risks, medications, immunosuppression.

3. Pattern & duration: Acute (<2 weeks) often infectious; prolonged fevers need wider differential (TB, autoimmune, malignancy).

4. Focused tests: CBC, ESR/CRP, blood cultures if febrile and systemically unwell, urinalysis, chest X-ray if respiratory symptoms. Use directed tests rather than blanket panels.

5. When to image: Localizing signs or persistent fever despite initial workup — consider ultrasound or CT based on clinical suspicion.

Case vignette

A 35-year-old with low-grade fever, weight loss and night sweats for 3 weeks. Chest X-ray shows upper-zone infiltrate — sputum sent and anti-TB therapy started after confirmatory microbiology.

Bottom line

Let clinical clues guide testing. Reserve invasive or high-cost diagnostics for when initial evaluation points the way.