What is the cause of acute wrist and leg pain in a male patient in his 40s with no history of injury or trauma?

Acute Wrist and Leg Pain in a Male in His 40s Without Trauma

The most likely diagnosis is acute inflammatory arthritis, particularly gout or pseudogout, which commonly presents as acute polyarticular pain in middle-aged men without injury, and you should immediately obtain plain radiographs followed by joint aspiration with synovial fluid analysis to confirm the diagnosis and rule out septic arthritis. 1

Initial Diagnostic Approach

Immediate Imaging

• Obtain plain radiographs of both the wrist and affected leg joints as the first-line study 1
• Radiographs are widely available and can identify early erosive changes, soft-tissue swelling, chondrocalcinosis (suggesting pseudogout), or other bone abnormalities that guide further workup 1
• Look specifically for periarticular soft-tissue swelling and joint effusions on the lateral view 1

Critical Next Step: Joint Aspiration

• If radiographs are normal or show nonspecific arthritis with clinical suspicion of inflammatory arthritis or infection, proceed immediately to joint aspiration 1
• Aspiration is the definitive diagnostic test to differentiate between crystal arthropathy (gout/pseudogout), septic arthritis, and other inflammatory conditions 1
• Synovial fluid analysis should include cell count with differential, Gram stain, culture, and crystal examination under polarized microscopy 1

Key Clinical Features to Assess

History Elements That Point to Inflammatory Arthritis

• Acute onset over hours to days (not gradual) 2, 3
• Polyarticular involvement (wrist AND leg) strongly suggests systemic inflammatory process rather than mechanical injury 1
• Morning stiffness lasting >30 minutes 1
• Constitutional symptoms such as fever, malaise, or weight loss 1
• Dietary triggers (alcohol, red meat, seafood for gout) or recent illness 2

Physical Examination Findings

• Warmth, erythema, and swelling over affected joints indicate active inflammation 1, 2
• Severe pain with passive range of motion out of proportion to examination suggests inflammatory or infectious etiology 2, 3
• Palpable tophi (for gout) or other extra-articular manifestations 2

Laboratory Workup

Essential Blood Tests

• Serum uric acid level (though normal levels do not exclude acute gout) 2
• Complete blood count to assess for leukocytosis suggesting infection 1
• Inflammatory markers (ESR, CRP) are elevated in inflammatory arthritis and infection 1
• Rheumatoid factor and anti-CCP antibodies if rheumatoid arthritis is suspected 1

Advanced Imaging When Indicated

MRI with IV Contrast

• If radiographs are normal or nonspecific and inflammatory arthritis is suspected, MRI with IV contrast is the next appropriate study 1
• MRI is superior for detecting early synovitis, bone marrow edema (osteitis), and erosions before they become visible on radiographs 1
• Enhancing bone marrow edema on MRI is the strongest predictor of future disease progression in early rheumatoid arthritis, even more than serologies 1
• Dynamic contrast-enhanced MRI can quantify active synovitis and guide early aggressive treatment decisions 1

Ultrasound as Alternative

• Power Doppler ultrasound can identify active synovitis and early erosions 1
• US is particularly useful when MRI is contraindicated or unavailable 1
• US can guide therapeutic joint injections if needed 1

Critical Differential Diagnoses to Consider

Septic Arthritis (Cannot Miss)

• Fever, severe pain, and inability to bear weight or use the joint demand immediate aspiration 1
• Septic arthritis is a medical emergency requiring urgent drainage and antibiotics 1
• Do not delay aspiration for imaging if septic arthritis is suspected 1

Crystal Arthropathy (Gout/Pseudogout)

• Most common cause of acute monoarticular or oligoarticular arthritis in middle-aged men 2
• Gout classically affects the first metatarsophalangeal joint but can involve wrists and other joints 2
• Pseudogout (calcium pyrophosphate deposition) commonly affects wrists and knees 2

Early Rheumatoid Arthritis

• Polyarticular involvement of small joints (including wrists) in a symmetric pattern 1
• May present acutely but more commonly has subacute onset 1, 2
• Early diagnosis and treatment within 3 months of symptom onset prevents irreversible joint damage 1

Reactive Arthritis

• Acute oligoarticular arthritis following gastrointestinal or genitourinary infection 2
• Ask about recent diarrhea, urethritis, or conjunctivitis 2

Viral Arthritis

• Parvovirus B19, hepatitis B/C, or other viral infections can cause acute polyarthritis 4
• Usually self-limited but requires exclusion of other causes 4

Common Pitfalls to Avoid

• Do not diagnose "wrist sprain" in the absence of trauma—this is a treacherous diagnosis that delays recognition of serious pathology 5
• Do not rely on serum uric acid alone to exclude gout—levels can be normal during acute attacks 2
• Do not delay aspiration if infection is suspected—septic arthritis causes irreversible joint destruction within days 1
• Do not assume bilateral involvement excludes infection—disseminated gonococcal infection can cause polyarticular septic arthritis 1
• Do not order MRI before radiographs—plain films are essential first-line imaging and may provide the diagnosis 1

Management Algorithm

1. Obtain plain radiographs of wrist and affected leg joints immediately 1
2. Perform joint aspiration if radiographs are normal/nonspecific or if infection/crystal arthropathy suspected 1
3. Send synovial fluid for cell count, Gram stain, culture, and crystal analysis 1
4. Obtain blood work: CBC, ESR, CRP, uric acid, RF, anti-CCP 1, 2
5. If aspiration is non-diagnostic and inflammatory arthritis suspected, proceed to MRI with IV contrast 1
6. Refer to rheumatology urgently if inflammatory arthritis confirmed to initiate disease-modifying therapy within the critical 3-month window 1