What is the initial treatment for psoriatic arthritis?

Initial Treatment for Psoriatic Arthritis

In patients with active psoriatic arthritis, a conventional synthetic disease-modifying antirheumatic drug (csDMARD) should be initiated rapidly, with methotrexate preferred in those with relevant skin involvement. 1

Treatment Algorithm

First-line Treatment

1. NSAIDs

   • Recommended as initial therapy for mild disease with musculoskeletal symptoms 1
   • Limited efficacy for skin lesions 1
   • Consider cardiovascular and gastrointestinal risk 1

2. Early initiation of csDMARDs

   • Should be started rapidly in patients with active disease 1
   • Particularly important for patients with:
     • Polyarthritis (≥5 swollen joints) 1
     • Structural damage with inflammation 1
     • High ESR/CRP 1
     • Clinically relevant extra-articular manifestations 1

3. Preferred csDMARD options

   • Methotrexate: First choice, especially with significant skin involvement 1, 2
   • Sulfasalazine: Alternative option 1, 3
   • Leflunomide: Alternative option 1, 3

Adjunctive Therapy

• Local glucocorticoid injections can be used as adjunctive therapy 1
• Systemic glucocorticoids may be used with caution at the lowest effective dose 1
  • Caution: Risk of post-steroid psoriasis flare 1

Disease Patterns and Specific Recommendations

Peripheral Arthritis

• Polyarthritis: Rapidly initiate csDMARD, preferably methotrexate 1
• Oligoarthritis/Monoarthritis: Consider csDMARD if poor prognostic factors present (structural damage, high ESR/CRP, dactylitis, nail involvement) 1

Axial Disease

• Traditional DMARDs (methotrexate, sulfasalazine, leflunomide) are not effective for axial manifestations 2
• For predominantly axial disease with insufficient response to NSAIDs, consider a TNF inhibitor 1
• If significant skin involvement is present with axial disease, an IL-17 inhibitor may be preferred 1

Enthesitis

• For unequivocal enthesitis with insufficient response to NSAIDs or local glucocorticoid injections, consider a biologic DMARD 1

Second-line Treatment (Inadequate Response to csDMARDs)

If there is inadequate response to at least one csDMARD:

• Biologic DMARDs (bDMARDs) should be initiated 1
  • TNF inhibitors are recommended as first biologic choice 1
  • For patients with significant skin involvement, IL-17 inhibitors or IL-12/23 inhibitors may be preferred 1

Treatment Failure Definition

• DMARD failure: Treatment for >3 months with >2 months at standard target dose without adequate response 2
• Inadequate response: No acceptable clinical improvement or evidence of progression of joint damage on radiographs 2

Monitoring

• Treatment should aim at reaching remission or low disease activity 1
• Regular disease activity assessment using validated measures (DAS28, ACR response criteria) 2
• Adjust therapy appropriately based on response 1

Important Considerations

• Gold salts, chloroquine, and hydroxychloroquine are not recommended for PsA 1, 2
• Careful monitoring of liver function with methotrexate due to potential increased hepatic toxicity in PsA compared to other rheumatic conditions 1
• In patients with sustained remission, cautious tapering of DMARDs may be considered 1

This treatment approach follows the most recent EULAR recommendations (2019) for psoriatic arthritis management, which emphasize early intervention with csDMARDs, particularly methotrexate for patients with skin involvement, and progression to biologics for those with inadequate response.