What is the treatment for psoriatic arthritis?

Treatment of Psoriatic Arthritis

The treatment of psoriatic arthritis should follow a stepwise approach, starting with NSAIDs for mild disease, progressing to conventional synthetic DMARDs for moderate to severe disease, and advancing to biologic DMARDs for patients who fail to respond to at least one DMARD therapy. 1

Disease Assessment and Treatment Goals

• Treatment goals should aim for remission or low disease activity through regular disease assessment and appropriate therapy adjustment
• Baseline evaluations should include:
  • Peripheral joint assessment (68 joints for tenderness; 66 joints for swelling)
  • Pain assessment
  • Patient global assessment of disease activity
  • Physical function measurement (e.g., HAQ)
  • Health-related quality of life assessment
  • Fatigue measurement
  • Acute phase reactants (CRP or ESR) 2

Treatment Algorithm

Mild Disease Management

1. First-line therapy: NSAIDs for musculoskeletal symptoms (Level A evidence) 1
2. Adjunctive therapy: Local glucocorticoid injections 1
3. Consider early DMARD initiation if poor prognostic factors are present:
   • Polyarticular disease
   • Elevated ESR
   • Structural damage
   • Dactylitis
   • Nail involvement 2, 1

Moderate to Severe Disease Management

1. First-line therapy: Rapidly initiate a conventional synthetic DMARD (csDMARD)

   • Methotrexate is preferred for patients with significant skin involvement (Level A evidence) 1, 3
   • Alternative csDMARDs include:
     • Sulfasalazine (Level A evidence)
     • Leflunomide (Level A evidence)
     • Ciclosporin (Level B evidence) 2, 1, 3

2. Second-line therapy: If inadequate response to at least one csDMARD after 3 months with at least 2 months at standard target dose, progress to biologic DMARD therapy 1

   • TNF inhibitors (etanercept, infliximab, adalimumab, certolizumab pegol) are recommended with Level A evidence 1, 4
   • For patients with significant skin involvement, consider IL-17 inhibitors or IL-12/23 inhibitors 1

3. Third-line therapy: If inadequate response to a biologic DMARD, consider:

   • Switching to another biologic DMARD, including within the same class
   • JAK inhibitor therapy 1

Special Considerations

Disease Patterns

• Polyarticular disease: Rapidly initiate csDMARD, preferably methotrexate 1
• Oligoarticular disease: Consider csDMARD if poor prognostic factors are present 1
• Axial disease with significant skin involvement: Consider IL-17 inhibitor 1
• Concomitant inflammatory bowel disease: Consider IL-12/23 inhibitors 1

Medication Details

• Etanercept dosing: 50 mg weekly for adult PsA 4
• Methotrexate: First-line DMARD with Level A evidence 1, 3
• Combination therapy: Multiple DMARDs may be considered for patients failing monotherapy 1

Important Cautions and Contraindications

• Systemic corticosteroids: Not typically recommended due to potential for post-steroid psoriasis flare 2, 1
• Contraindicated agents: Gold salts, chloroquine, and hydroxychloroquine are not recommended for PsA 2, 1
• Ciclosporine limitations: Should be limited to less than 12 consecutive months due to cumulative toxicity concerns 1
• TNF inhibitor precautions: Patients treated with TNF inhibitors like etanercept are at increased risk for serious infections and malignancies 4
  • Test for latent tuberculosis before and during therapy
  • Complete all age-appropriate vaccinations prior to initiating treatment
  • Monitor for signs and symptoms of infection during treatment

Treatment Monitoring

• Regular assessment of disease activity using validated measures such as:
  • 28-joint Disease Activity Score (DAS28)
  • American College of Rheumatology (ACR) percentage response criteria
• Consider treatment failure if:
  • No acceptable clinical improvement after appropriate duration of therapy
  • Evidence of progression of joint damage on radiographs 2
• Consider cautious tapering of DMARDs in patients who achieve sustained remission 1