What is the recommended workup and treatment for gout?

Workup and Treatment for Gout

The definitive diagnosis of gout requires identification of monosodium urate (MSU) crystals in synovial fluid, supported by clinical features and imaging findings, followed by a treat-to-target approach with urate-lowering therapy (ULT) to achieve serum uric acid levels below 6 mg/dL. 1

Diagnostic Workup

Definitive Diagnosis

• Crystal identification: Synovial fluid analysis for MSU crystals is the gold standard for diagnosis 1
• If crystal identification is not possible, diagnosis can be supported by:
  • Clinical features: Podagra (first MTP joint involvement), presence of tophi, rapid response to colchicine
  • Imaging findings: Characteristic changes on ultrasound or dual-energy CT 1

Essential Laboratory Tests

• Serum uric acid level: Baseline measurement (though may be normal during acute flares)
• Renal function: Creatinine clearance assessment (impacts medication dosing) 1
• Cardiovascular risk assessment: Lipid profile, blood pressure, glucose 1

Comorbidity Screening

• Systematically screen for associated conditions:
  • Renal impairment
  • Coronary heart disease
  • Heart failure
  • Stroke
  • Peripheral arterial disease
  • Obesity
  • Hyperlipidemia
  • Hypertension
  • Diabetes 1

Treatment Approach

Acute Gout Flare Management

1. First-line options (start as early as possible):

   • Colchicine: 1 mg loading dose, followed by 0.5 mg one hour later on day 1 (within 12 hours of flare onset) 1, 2
   • NSAIDs: With PPI if appropriate
   • Corticosteroids: Oral (30-35 mg/day prednisolone for 3-5 days) or intra-articular injection 1

2. Special populations:

   • Renal impairment: Avoid colchicine and NSAIDs in severe renal impairment 1, 2
   • Drug interactions: Avoid colchicine with strong P-glycoprotein/CYP3A4 inhibitors (e.g., cyclosporin, clarithromycin) 1, 2
   • Multiple contraindications: Consider IL-1 blockers if colchicine, NSAIDs, and corticosteroids are contraindicated 1

Long-term Management

Urate-Lowering Therapy (ULT)

1. First-line ULT:

   • Allopurinol: Start at low dose (50-100 mg daily, lower in renal impairment) and titrate upward to reach target 1, 3
   • Gradually increase dose every 2-5 weeks until target serum urate is achieved 3

2. Second-line options (if allopurinol fails or is not tolerated):

   • Febuxostat 1, 3
   • Uricosurics (e.g., probenecid, benzbromarone) 1
   • Combination therapy: Xanthine oxidase inhibitor plus uricosuric 1

3. Severe refractory gout:

   • Pegloticase: Reserved for severe cases when all other options have failed 1, 3

Flare Prophylaxis

• Duration: First 6 months of ULT initiation 1
• Medication options:
  • Colchicine: 0.5-1 mg daily (reduce dose in renal impairment) 1, 3, 2
  • Low-dose NSAIDs: If colchicine contraindicated 1
  • Low-dose corticosteroids: Alternative option 1

Treatment Targets

• Serum urate goal: <6 mg/dL (360 μmol/L) for most patients 1, 4
• More aggressive target: <5 mg/dL (300 μmol/L) for severe gout with tophi 1, 4
• Duration: Continue treatment for at least 3 months after reaching target (6 months if tophi present) 5

Lifestyle Modifications

• Weight management: Weight loss if appropriate 1
• Diet recommendations:
  • Avoid/limit: Alcohol (especially beer and spirits), sugar-sweetened drinks, excessive meat and seafood intake 1, 5
  • Encourage: Low-fat dairy products, adequate hydration (2.5-3L daily) 1, 3
• Regular exercise 1

Monitoring

• Serum uric acid levels: Regular monitoring to ensure target is maintained 1
• Flare frequency: Track to assess treatment efficacy 1
• Tophi size: Monitor for resolution 1
• Renal function: Regular monitoring, especially in patients with pre-existing kidney disease or on allopurinol 3

Common Pitfalls to Avoid

1. Inadequate dosing: Failing to titrate allopurinol to achieve target urate levels 3, 6
2. Discontinuing ULT during acute flares: ULT should be continued during flares 1
3. Insufficient prophylaxis: Not providing flare prophylaxis when initiating ULT 1
4. Treating asymptomatic hyperuricemia: Not recommended to prevent gouty arthritis, renal disease, or CV events 1
5. Inadequate patient education: Failure to educate patients about the chronic nature of gout and importance of long-term ULT 1
6. Inappropriate colchicine use: Using high doses or in patients with contraindications 2

By following this systematic approach to diagnosis and management, gout can be effectively controlled and potentially cured through sustained reduction in serum urate levels.