What is the initial approach to managing a patient with fever and arthralgia?

Initial Management of Fever with Arthralgia

Immediately exclude malaria in any patient with fever and arthralgia who has traveled to endemic areas within the past year, and simultaneously rule out life-threatening infections including dengue, enteric fever, and rickettsial diseases based on geographic exposure. 1

Immediate Diagnostic Priorities

Travel and Exposure History

• Document specific countries/regions visited, exact dates of travel, and timing of symptom onset relative to return 1
• Identify fresh-water exposure (lakes/rivers) suggesting leptospirosis or schistosomiasis, particularly 4-8 weeks post-exposure 1
• Assess for tick exposures or outdoor activities in endemic areas for rickettsial diseases 2
• Evaluate contact with livestock or consumption of unpasteurized dairy products (brucellosis) 1
• Note any insect bites, particularly day-biting mosquitoes in tropical regions 1

Critical Clinical Features to Document

• Timing of fever pattern: High-spiking fevers suggest dengue, chikungunya, or adult-onset Still's disease 1, 3
• Rash characteristics: Salmon-colored transient rash suggests Still's disease; urticarial rash with eosinophilia suggests Katayama syndrome 1, 3
• Joint involvement pattern: Severe back pain and arthralgia are characteristic of dengue; polyarthritis suggests acute rheumatic fever or reactive arthritis 1, 4
• Respiratory symptoms: Cough and dyspnoea developing 3 days after fever onset may indicate influenza-related complications 1

Geographic-Specific Differential Diagnosis

Returning from Asia or South America

• Dengue fever is the most common arbovirus in travelers from Asia 1
• Obtain dengue PCR if symptoms present 1-8 days; IgM if >5 days post-symptom onset 1
• Chikungunya presents with severe arthralgia, particularly affecting small joints 1
• Diagnose via PCR early (days 1-4) or IgM/IgG from days 5-7 1
• Enteric fever (typhoid/paratyphoid) is the commonest serious tropical disease from Asia requiring treatment after malaria exclusion 1

Returning from Sub-Saharan Africa

• Malaria must be excluded first - it is the most important potentially fatal cause 1
• Obtain three malaria tests over 72 hours if initial tests negative but suspicion remains 2
• Blood cultures for enteric fever (80% sensitive in first week) 1
• Consider Katayama syndrome if fresh-water exposure 4-8 weeks prior with eosinophilia >0.45 × 10⁹/L 1

No Recent Travel

• Adult-onset Still's disease: Look for extreme hyperferritinemia, leukocytosis, and salmon-colored rash with high-spiking fevers 3
• Acute rheumatic fever: Requires documented preceding Group A Streptococcal infection plus Jones criteria (two major or one major and two minor manifestations) 4
• Q fever: Consider if exposure to livestock; diagnose with phase II IgG ≥1:128 or fourfold rise in paired sera 1

Initial Laboratory Investigations

Mandatory First-Line Tests

• Malaria testing (thick and thin blood films) - repeat up to three times over 72 hours if endemic area exposure 1, 2
• Blood cultures (obtain before antibiotics) - critical for enteric fever and bacteremia 1
• Complete blood count: Thrombocytopenia suggests dengue; eosinophilia suggests Katayama syndrome; leukocytosis with extreme hyperferritinemia suggests Still's disease 1, 3
• Inflammatory markers (CRP, ESR) and ferritin 3
• Liver function tests and lactate dehydrogenase 1

Geographic/Exposure-Specific Testing

• Dengue PCR (days 1-8) or IgM (>day 5) for Asia/South America travel 1
• Chikungunya PCR or serology for recent epidemic areas 1
• Schistosomiasis serology if fresh-water exposure 4-8 weeks prior (mean seroconversion 1.6 months) 1
• Q fever serology if livestock exposure 1

Empiric Treatment Decisions

When to Treat Empirically Without Waiting for Results

For suspected enteric fever with clinical instability: Start ceftriaxone immediately; ciprofloxacin remains alternative for sub-Saharan Africa travel 1

For suspected Katayama syndrome: The combination of fresh-water exposure 4-8 weeks previously, fever, urticarial rash, and eosinophilia warrants empiric praziquantel 40 mg/kg in divided doses 4 hours apart, repeated 6-8 weeks later 1

For suspected Q fever with acute presentation: Initiate doxycycline 100 mg twice daily immediately 1

Symptomatic Management

• Antipyretics and analgesics for comfort and to facilitate coughing 1
• Avoid aspirin in dengue due to bleeding risk 1
• NSAIDs appropriate for symptomatic relief in most non-dengue cases 1
• Manage dengue as outpatient with daily FBC monitoring unless high hematocrit or falling platelets indicate shock risk 1

Red Flags Requiring Immediate Hospitalization

• Evidence of organ dysfunction, severe thrombocytopenia, or mental status changes 2
• Oxygen saturation <92% or respiratory distress 1
• Signs of dengue hemorrhagic fever or shock syndrome 1
• Confusion, seizures, or reduced Glasgow coma scale (cerebral malaria or hypoglycemia) 1
• Hypotension with systolic blood pressure compromise 1

Common Pitfalls

• Do not dismiss malaria based on single negative test - requires three tests over 72 hours for confident exclusion 2
• Do not delay treatment for RMSF or meningococcemia while awaiting laboratory confirmation 2
• Do not attribute all fever/arthralgia to viral illness without excluding treatable bacterial causes 1
• Do not overlook adult-onset Still's disease in patients with negative infectious workup and extreme hyperferritinemia 3
• Remember cross-reaction of flavivirus IgG (dengue, yellow fever, Japanese encephalitis, tick-borne encephalitis vaccines) complicates serologic interpretation 1