How to manage elevated uric acid levels in patients with psoriasis?

Management of Elevated Uric Acid Levels in Patients with Psoriasis

Patients with psoriasis who have elevated uric acid levels should receive dose-adjusted uricosuric medications, with particular attention to those receiving hydroxyurea therapy which can further raise serum uric acid levels. 1

Prevalence and Significance of Hyperuricemia in Psoriasis

Hyperuricemia is a common finding in psoriasis patients, affecting approximately 20% of individuals with the condition 2. Several studies have demonstrated that:

• Serum uric acid levels are significantly higher in psoriasis patients compared to healthy controls 3
• There is a positive correlation between Psoriasis Area Severity Index (PASI) scores and serum uric acid levels 3
• Obese psoriasis patients have significantly higher uric acid levels than non-obese patients with psoriasis 2
• Hyperuricemia in psoriasis results from rapid keratinocyte differentiation and inflammatory cell infiltration into psoriatic lesions 4

Monitoring Recommendations

For psoriasis patients, especially those on systemic therapies:

• Monitor serum uric acid levels as part of routine laboratory assessment
• Pay particular attention to uric acid levels in patients with:
  • Moderate-to-severe psoriasis
  • Obesity
  • Elevated triglycerides
  • Psoriatic arthritis (present in approximately 25% of patients with hyperuricemia) 5

Management Algorithm for Elevated Uric Acid in Psoriasis

1. For Patients on Hydroxyurea Therapy

• Hydroxyurea can raise serum uric acid levels and may require dose adjustment of uricosuric medications 1
• Monitor uric acid levels regularly in these patients
• Consider dose adjustment of uricosuric medications based on uric acid levels

2. For Patients with Asymptomatic Hyperuricemia

• Routine treatment is not recommended unless uric acid levels are very high (>9 mg/dL) 6
• Focus on addressing modifiable risk factors:
  • Weight management for obese patients
  • Dietary modifications
  • Adequate hydration

3. For Patients with Symptomatic Hyperuricemia or Gout

• Initiate urate-lowering therapy with xanthine oxidase inhibitors:
  • Allopurinol as first-line therapy 6, 7
  • Start at low dose (100 mg daily) and increase at weekly intervals by 100 mg until target uric acid level is achieved 7
  • Target serum uric acid level <6 mg/dL for most patients 6
  • For severe cases, target <5 mg/dL 6

4. For Patients with Renal Impairment

• Adjust allopurinol dosing based on creatinine clearance 7:
  • Creatinine clearance 10-20 mL/min: 200 mg daily
  • Creatinine clearance <10 mL/min: maximum 100 mg daily
  • Extreme renal impairment (clearance <3 mL/min): extend dosing interval

Special Considerations and Precautions

Medication Interactions

• Use caution when combining allopurinol with azathioprine (if used for psoriasis)
  • Allopurinol increases risk of pancytopenia with azathioprine 1
  • If used concurrently, lower the azathioprine dose by 75% 1

Monitoring for Complications

• Be vigilant for uric acid crystal nephropathy, especially in patients with erythrodermic psoriasis 4
  • This rare but serious complication can cause acute kidney injury
  • Treatment includes aggressive fluid resuscitation, urine alkalinization, and uric acid-lowering agents

Severe Cases

• In cases of erythrodermic psoriasis with hyperuricemia:
  • Monitor renal function closely
  • Consider prophylactic treatment with allopurinol or rasburicase for severe cases 4
  • Maintain adequate hydration

Treatment Efficacy Assessment

• Monitor serum uric acid levels every 2-5 weeks during dose titration 6
• Once target level is achieved, check levels every 6 months 6
• Continue treatment indefinitely in patients with established gout 6

By following this approach, clinicians can effectively manage the elevated uric acid levels that commonly occur in patients with psoriasis, potentially reducing the risk of gout and other uric acid-related complications.