What is the appropriate workup and treatment for a patient presenting with hot swollen joints?

Workup and Management of Hot Swollen Joints

The diagnostic workup for a hot swollen joint must include joint aspiration to rule out septic arthritis, which is a medical emergency, followed by appropriate laboratory and imaging studies to determine the specific etiology and guide treatment. 1, 2

Initial Assessment

History

• Duration and onset of symptoms
• Pattern of joint involvement (monoarticular vs. polyarticular)
• Morning stiffness duration (>30 minutes suggests inflammatory arthritis)
• Response to NSAIDs or corticosteroids (improvement suggests inflammatory cause)
• Previous episodes of similar symptoms
• Recent infections, trauma, or procedures
• Medication history
• Occupational exposures

Physical Examination

• Complete examination of all peripheral joints for tenderness, swelling, and range of motion
• Assessment of joint temperature, erythema, and effusion
• Examination of the spine if back pain is present
• Skin examination for rashes, tophi, or nodules
• Systemic examination for signs of infection or other systemic diseases

Diagnostic Algorithm

Step 1: Joint Aspiration (Critical First Step)

• Perform joint aspiration for any hot, swollen joint to rule out septic arthritis 1, 3
• Send synovial fluid for:
  • Cell count and differential (>50,000 WBC/mm³ with >90% neutrophils suggests infection)
  • Crystal analysis (polarized light microscopy)
  • Gram stain and culture
  • Glucose and protein levels

Step 2: Laboratory Tests

• Complete blood count with differential
• Inflammatory markers (ESR, CRP)
• Autoimmune panel including:
  • Rheumatoid factor (RF)
  • Anti-CCP antibodies (higher specificity for RA at 95-98%) 4
  • ANA if systemic autoimmune disease is suspected
• Uric acid levels (if gout is suspected)
• HLA-B27 testing if reactive arthritis or spondyloarthropathy is suspected 1

Step 3: Imaging Studies

• Plain radiographs of affected joints to:
  • Exclude metastases
  • Evaluate joint damage (erosions)
  • Assess for chondrocalcinosis (CPPD)
• Consider ultrasound ± MRI for:
  • Persistent arthritis unresponsive to treatment
  • Suspicion of differential diagnoses (metastatic lesions, septic arthritis)
  • Evaluation of synovitis and effusion 1

Management Based on Diagnosis

1. Septic Arthritis (Medical Emergency)

• Immediate orthopedic consultation
• Joint drainage (arthrocentesis or surgical)
• Empiric broad-spectrum antibiotics pending culture results
• Hospitalization for intravenous antibiotics

2. Crystal-Induced Arthritis (Gout/Pseudogout)

• NSAIDs (e.g., ibuprofen) for acute attacks if not contraindicated 5
• Colchicine as an alternative
• Consider intra-articular corticosteroid injections for large joints 1
• For gout: urate-lowering therapy after acute attack resolves
• For pseudogout: treat underlying metabolic conditions

3. Inflammatory Arthritis (RA, Psoriatic Arthritis, etc.)

• Grade 1 (Mild):

  • NSAIDs and/or acetaminophen for pain relief 1
  • Consider early rheumatology referral if symptoms persist >4 weeks

• Grade 2 (Moderate):

  • NSAIDs at higher doses
  • If inadequately controlled, initiate prednisone 10-20 mg/day for 4-6 weeks 1, 6
  • Slow taper over 4-6 weeks if improvement occurs
  • Consider intra-articular corticosteroid injections for large joints
  • Rheumatology referral

• Grade 3-4 (Severe):

  • Oral prednisone 0.5-1 mg/kg 1
  • Consider disease-modifying antirheumatic drugs (DMARDs):
    • Synthetic: methotrexate, leflunomide
    • Biologic: TNF-α or IL-6 receptor inhibitors
  • Urgent rheumatology consultation 1, 4

4. Reactive Arthritis

• NSAIDs for symptom control
• Treat underlying infection if identified
• Consider short-term corticosteroids for severe symptoms
• Rheumatology referral if symptoms persist

Monitoring and Follow-up

• Patients with inflammatory arthritis should be monitored with serial rheumatologic examinations, including inflammatory markers, every 4-6 weeks after treatment initiation 1
• Plain radiographs of hands and feet should be performed every 6-12 months during the first few years to monitor joint damage in patients with inflammatory arthritis 4
• Early recognition of inflammatory arthritis is critical to avoid erosive joint damage 1

Important Caveats

• Never delay joint aspiration when septic arthritis is suspected - it is a medical emergency with significant morbidity and mortality 7
• Crystal-induced arthropathies (gout and pseudogout) are common causes of hot swollen joints but can coexist with infection 8
• A negative joint aspirate culture does not completely rule out septic arthritis if clinical suspicion remains high 3
• Consider Charcot neuroarthropathy in patients with diabetes who present with a red, hot, swollen foot, even in the presence of ulceration or infection 1
• Early referral to rheumatology is recommended for persistent joint swelling or arthralgia lasting >4 weeks 1, 4
• Monoarticular rheumatoid arthritis is a rare cause of a single hot joint but should be considered in the differential diagnosis 9

By following this structured approach, clinicians can efficiently diagnose and manage patients presenting with hot swollen joints, ensuring appropriate treatment and preventing long-term joint damage.