What is the recommended treatment for a patient with psoriatic arthritis?

Treatment of Psoriatic Arthritis

The recommended treatment for psoriatic arthritis follows a stepwise approach, starting with NSAIDs, progressing to conventional synthetic DMARDs (particularly methotrexate), followed by biologics (TNF inhibitors, IL-17 inhibitors, or IL-12/23 inhibitors) for inadequate responders. 1, 2

Initial Treatment Approach

First-line Therapy

• NSAIDs should be used as initial therapy for mild musculoskeletal symptoms 1
  • Provides symptomatic relief but should not be the only therapy beyond 3 months if active disease persists 2
  • Does not modify disease progression or treat skin manifestations

Second-line Therapy

• Conventional synthetic DMARDs (csDMARDs) should be initiated rapidly, particularly in patients with polyarthritis 1
  • Methotrexate is the preferred csDMARD, especially in patients with relevant skin involvement 1, 2
    • Recommended dosage: 15-25 mg/week 2
    • Low-quality evidence suggests methotrexate is more effective than placebo for disease response, with 16% more responders (NNTB of 6) 3
  • Other csDMARD options include sulfasalazine and leflunomide 2

For Monoarthritis or Oligoarthritis

• Consider csDMARDs if poor prognostic factors are present (structural damage, high ESR/CRP, dactylitis, nail involvement) 1
• Local glucocorticoid injections can be used as adjunctive therapy 1

Treatment for Inadequate Responders

Third-line Therapy (After csDMARD Failure)

• Biological DMARDs (bDMARDs) should be initiated in patients with peripheral arthritis and inadequate response to at least one csDMARD 1
  • TNF inhibitors (adalimumab, etanercept) are generally preferred as first biologic 1, 2
    • Adalimumab: 40 mg every other week 4
    • Etanercept: 50 mg weekly 5
  • IL-17 inhibitors or IL-12/23 inhibitors may be preferred when there is significant skin involvement 1, 2

Fourth-line Therapy

• JAK inhibitors may be considered in patients with inadequate response to at least one csDMARD and one bDMARD 1
• PDE4 inhibitors may be considered in patients with mild disease and inadequate response to csDMARDs 1

Special Considerations

Axial Disease

• For predominantly axial disease with insufficient response to NSAIDs, a bDMARD should be considered 1
  • TNF inhibitors are typically first choice
  • IL-17 inhibitors may be preferred with relevant skin involvement 1
  • Note that conventional DMARDs are not effective for axial manifestations 2

Enthesitis

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

Treatment Switching

• If a patient fails to respond adequately to a bDMARD, switching to another bDMARD or targeted synthetic DMARD should be considered 1
• This includes switching within the same class 1

Monitoring and Safety

Before Treatment

• Test for latent TB before initiating biologics 4, 5
• Screen for contraindications to specific therapies:
  • TNF inhibitors: recurrent infections, congestive heart failure, demyelinating disease 1

During Treatment

• Regular monitoring of disease activity using validated measures 2
• Monitor for adverse effects:
  • TNF inhibitors: serious infections, malignancies (including lymphoma) 4, 5
  • Methotrexate: liver damage, hematologic abnormalities 6

Tapering

• In patients with sustained remission, cautious tapering of DMARDs may be considered 1

Combination Therapy

• Methotrexate can be used in combination with biologics 4, 5
• Low-dose prednisolone (10 mg on alternate days) combined with methotrexate may be beneficial in severe cases 7, though systemic glucocorticoids should be used with caution at the lowest effective dose 1

The treatment approach should be guided by disease severity, pattern of joint involvement, presence of extra-articular manifestations, and comorbidities, with the primary goal of maximizing health-related quality of life through control of symptoms, prevention of structural damage, and normalization of function 1, 2.