How to manage a patient with ankle and knee pain, recent gastrointestinal (GI) infection, elevated inflammatory markers (Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP)), and no fever?

Management of Post-Infectious Reactive Arthritis

This patient should be treated with NSAIDs as first-line therapy for post-infectious reactive arthritis following gastrointestinal infection. 1, 2

Clinical Diagnosis

This presentation is classic for reactive arthritis (ReA) following gastrointestinal infection:

• Asymmetric oligoarthritis (ankle and knee) developing 2-4 weeks after GI infection is pathognomonic for reactive arthritis 1
• Elevated inflammatory markers (ESR, CRP) with normal other labs and absence of fever supports a post-infectious inflammatory arthropathy rather than septic arthritis 3, 1
• The 2-week interval between GI infection and joint symptoms fits the typical timeline for reactive arthritis 1

First-Line Treatment: NSAIDs (Answer B)

NSAIDs are the recommended initial therapy for reactive arthritis:

• NSAIDs control inflammation and symptoms in the majority of reactive arthritis cases and should be tried first before escalating to other immunosuppressive agents 2
• CRP rises and falls more rapidly than ESR with treatment response, making it useful for monitoring NSAID efficacy 1
• NSAIDs are effective for controlling clinical manifestations of inflammation in post-infectious arthropathies 2

Practical NSAID Regimen:

• Use full anti-inflammatory doses (e.g., naproxen 500mg twice daily or ibuprofen 600-800mg three times daily) 2
• Continue for 2-4 weeks with clinical reassessment 1
• Monitor ESR/CRP every 1-3 months until remission 1, 4

Why NOT the Other Options

Steroids (Option A) - Reserve for refractory cases:

• Corticosteroids are not first-line for reactive arthritis 2
• Should be reserved for patients who fail NSAIDs or have severe, disabling symptoms 2
• Risk-benefit ratio favors trying NSAIDs first in this uncomplicated presentation 2

Methotrexate (Option C) - Only for chronic/recurrent disease:

• Disease-modifying agents like methotrexate are indicated only when reactive arthritis becomes chronic (>3 months) or recurrent 2
• This patient has acute symptoms of only 2 weeks duration 1
• Methotrexate requires 6-12 weeks to show effect, making it inappropriate for acute management 2

Aspirin (Option D) - Insufficient anti-inflammatory potency:

• Aspirin at analgesic doses lacks sufficient anti-inflammatory effect for reactive arthritis 2
• NSAIDs are superior to aspirin for inflammatory arthropathies 2

Critical Follow-Up Strategy

Monitor treatment response systematically:

• Repeat ESR and CRP in 2-4 weeks to assess response to NSAIDs 1, 4
• Clinical improvement should precede laboratory normalization - focus on pain reduction and functional improvement 1
• If no improvement after 4-6 weeks of NSAIDs, consider short course of oral corticosteroids (prednisone 20-40mg daily) 2
• If symptoms persist beyond 3 months, refer to rheumatology for consideration of methotrexate or other DMARDs 2

Important Pitfalls to Avoid

• Do not escalate to steroids or methotrexate without adequate NSAID trial - most reactive arthritis resolves with NSAIDs alone 2
• Do not dismiss the diagnosis if inflammatory markers normalize but symptoms persist - clinical assessment takes precedence 1, 5
• Rule out septic arthritis if fever develops or single joint becomes hot/swollen - this would require joint aspiration 3
• Exclude inflammatory bowel disease if GI symptoms persist or recur, as this changes management entirely 3