Is there any use in checking uric acid levels during a gout flare?

Checking Serum Uric Acid Levels During Gout Flares

Checking serum uric acid levels during an acute gout flare is not recommended as these measurements are often misleading and do not contribute to the immediate management of the acute attack. 1, 2

Rationale Against Checking Uric Acid During Flares

• Misleading Results: During acute gout flares, serum uric acid (SUA) levels may be normal or even low despite active crystal-induced inflammation 2, 1
• No Impact on Acute Management: Treatment decisions for the acute flare are based on clinical presentation rather than SUA levels 1
• Delayed Treatment Concerns: Waiting for laboratory results may unnecessarily delay initiation of appropriate anti-inflammatory therapy 1

Evidence from Guidelines

The American College of Rheumatology (ACR) guidelines explicitly recommend against delaying treatment of acute gout flares to obtain SUA levels 1. Similarly, the European League Against Rheumatism (EULAR) emphasizes prompt intervention for acute flares without waiting for laboratory confirmation 2.

The Gout, Hyperuricemia and Crystal-Associated Disease Network (G-CAN) consensus statement notes that while serum urate is the most important risk factor for gout, levels during acute attacks may be normal and therefore not diagnostically useful 2.

When Uric Acid Testing IS Appropriate

While checking SUA during flares is not recommended, measuring uric acid levels is important in other contexts:

1. Between flares (intercritical period) to:

   • Establish baseline hyperuricemia
   • Guide urate-lowering therapy (ULT) decisions
   • Monitor treatment efficacy

2. Target levels for ULT:

   • <6 mg/dL (360 μmol/L) for most patients 2
   • <5 mg/dL (300 μmol/L) for patients with severe gout 2

Management Algorithm for Gout

1. Acute flare management:

   • Initiate treatment promptly without waiting for SUA results
   • Use colchicine (within 12 hours of onset), NSAIDs, or corticosteroids based on patient factors 1
   • Consider intra-articular steroid injection for monoarticular flares 1

2. After flare resolution:

   • Check SUA level to guide long-term management
   • Consider ULT for patients with:
     • Frequent flares (≥2/year)
     • Tophi
     • Radiographic damage from gout
     • Urolithiasis 1

3. ULT monitoring:

   • Regular SUA monitoring to ensure target levels are maintained
   • Adjust medication dosing as needed

Common Pitfalls to Avoid

• Pitfall #1: Delaying treatment of acute flares while waiting for SUA results
• Pitfall #2: Misinterpreting normal SUA during a flare as absence of gout
• Pitfall #3: Starting ULT during an acute flare without concurrent anti-inflammatory prophylaxis
• Pitfall #4: Failing to monitor SUA levels after initiating ULT

Conclusion

While serum uric acid is central to gout pathophysiology and management, checking levels during an acute flare provides little clinical value and may delay appropriate treatment. The focus during flares should be on prompt anti-inflammatory therapy, with SUA measurement reserved for the intercritical period to guide long-term management decisions.