What is the appropriate initial evaluation and treatment approach for a patient with suspected gout, considering demographic information and comorbid conditions such as kidney disease and hypertension?

Workup of Suspected Gout

The definitive diagnosis of gout requires demonstration of monosodium urate (MSU) crystals in synovial fluid or tophus aspirates, and joint aspiration should be performed whenever feasible, especially for first presentations or atypical cases. 1

Clinical Assessment

Key Clinical Features to Identify

• Rapid onset of severe pain, swelling, and tenderness reaching maximum intensity within 6-12 hours, with overlying erythema is highly suggestive of crystal inflammation 1
• Podagra (first metatarsophalangeal joint involvement) has 96% sensitivity and 97% specificity for gout 1
• Look for involvement of other typical sites: ankle, knee, wrist, small hand joints, Achilles tendon, and olecranon bursae 2, 3
• Document previous similar episodes and pattern of attacks 2

Critical Diagnostic Pitfall

Serum uric acid levels do NOT confirm or exclude gout - many people with hyperuricemia never develop gout, and during acute attacks serum uric acid may be normal 1, 2. Do not rely on hyperuricemia alone for diagnosis.

Definitive Diagnostic Testing

Joint Aspiration (Gold Standard)

• Perform arthrocentesis on any undiagnosed inflamed joint to identify MSU crystals under polarized light microscopy 1
• MSU crystal identification has 84% sensitivity and approaches 100% specificity 2
• Always send synovial fluid for Gram stain and culture even if MSU crystals are identified, as gout and septic arthritis can coexist 1
• Aspiration can be performed during intercritical periods from asymptomatic joints to establish diagnosis 1

Alternative Imaging When Aspiration Not Feasible

• Ultrasound: 74% sensitivity, 88% specificity for double contour sign 2
• Dual-energy CT: 85-100% sensitivity, 83-92% specificity for MSU crystal deposition 2

Laboratory Evaluation

Essential Tests

• Serum uric acid level - important risk factor but not diagnostic; obtain for baseline and treatment monitoring 1
• Serum creatinine and estimated GFR - essential for treatment planning, as chronic kidney disease increases gout risk 4.95-fold 2
• Complete blood count - to assess for infection and baseline before treatment 4

Selective Testing

• 24-hour urine uric acid excretion should be determined in patients with:
  • Family history of young-onset gout 1
  • Onset of gout before age 25 1
  • History of renal calculi 1

Comorbidity Assessment

Systematically evaluate for metabolic syndrome components and cardiovascular risk factors, as these are strongly associated with gout and influence treatment decisions 1, 2:

• Obesity - measure BMI and waist circumference 1
• Hypertension - document blood pressure and current antihypertensive medications (especially diuretics) 1, 2
• Hyperglycemia/diabetes - fasting glucose or HbA1c 1
• Hyperlipidemia - lipid panel 1
• Chronic kidney disease - creatinine clearance calculation 1, 2
• Cardiovascular disease - document history of ischemic heart disease or heart failure 1

Radiographic Evaluation

• Plain radiographs are NOT useful for confirming diagnosis of early or acute gout 1
• Radiographs may be helpful for differential diagnosis and can show typical features (punched-out erosions with overhanging edges) in chronic tophaceous gout 1

Medication Review

Document current medications that may contribute to hyperuricemia:

• Loop or thiazide diuretics - consider alternative antihypertensives (losartan or calcium channel blockers preferred) 1
• Aspirin - even low-dose can affect uric acid levels 1
• Cyclosporine or tacrolimus - increases gout risk 1

Risk Stratification for Treatment Planning

After diagnosis is established, stratify patients to determine urgency of urate-lowering therapy initiation 1:

High priority for early ULT:

• Age <40 years at presentation 1
• Serum uric acid >8.0 mg/dL (480 μmol/L) 1
• Presence of tophi, chronic arthropathy, or frequent attacks 1
• Comorbidities: renal impairment, hypertension, ischemic heart disease, heart failure 1