Psoriatic Arthritis

Background

• Psoriatic arthritis is a seronegative inflammatory spondyloarthritis associated with mild-to-very severe psoriasis and joint manifestations.
• Psoriatic arthritis is reported in < 1% of the general population, but in about 20%-30% of patients with psoriasis.
• Psoriatic arthritis occurs equally in men and women and can occur at any age.
  • It most commonly presents in patients aged 30-50 years.
  • About 80% of patients have mild-to-moderate disease, and 20% have moderate-to-severe disease.

Evaluation

• The clinical presentation of psoriatic arthritis is variable and may change over time.
  • Peripheral joint disease occurs in 95% of patients, usually as a polyarthritis (≥ 5 joints affected).
    • Distribution of involved joints tends to be asymmetric (unlike rheumatoid arthritis).
    • Distal interphalangeal joint involvement is common (unlike rheumatoid arthritis).
    • Symptoms may include pain, morning stiffness, swelling, and tenderness in joints and the surrounding ligaments and tendons.
    • The severity of arthritis and skin symptoms usually do not correlate with each other.
    • Axial (spinal) disease is part of the presentation in about 5% of patients, and patients may present with both peripheral and axial involvement.
  • Most patients will have psoriasis before the onset of psoriatic arthritis, but 14%-20% of patients have been reported to develop psoriatic arthritis before or at the same time as psoriasis.
  • Scalp lesions, nail dystrophy, intergluteal/perianal lesions, and the presence of more severe and extensive psoriasis are associated with a higher risk of developing psoriatic arthritis
  • May be associated with dactylitis, enthesitis, inflammatory back pain, or nail lesions.
• Consider psoriatic arthritis in patients with joint inflammation (particularly asymmetric involvement), the absence of rheumatoid factor, and typical psoriatic skin and nail lesions.
• Although developed as classification criteria, the diagnosis may be made using the CASPAR criteria in patients with inflammatory joint disease (Strong recommendation). The Moll and Wright criteria are still commonly used.
• X-ray imaging showing bone proliferation and bone resorption will help confirm the diagnosis and distinguish psoriatic arthritis from rheumatoid arthritis.
• Psoriatic arthritis needs to be distinguished from other seronegative spondyloarthropathies such as ankylosing spondylitis, reactive arthritis, and enteropathic arthritis (arthritis associated with inflammatory bowel disease).

Management

• Management of skin disease is the same as for patients with psoriasis that is not associated with musculoskeletal problems including:
  • topical emollients, corticosteroids, vitamin D analogs, tazarotene, dithranol (anthralin), and coal tar
  • phototherapy with psoralen plus ultraviolet A (PUVA) or narrowband ultraviolet B (UVB)
  • traditional nonbiologic disease-modifying antirheumatic drugs (DMARDs) (methotrexate [MTX], cyclosporine A [CSA], acitretin, fumaric acid esters)
  • phosphodiesterase (PDE)4 inhibitor (apremilast)
  • biologic therapy (tumor necrosis factor [TNF] inhibitors, interleukin [IL] inhibitors [IL-12/23i, IL-17i])
  • see Psoriasis for further details
• Management of peripheral arthritis:
  • The primary treatment goal is to achieve minimal disease activity, maximize health-related quality of life and functional status, prevent structural damage, and minimize complications.
  • Nonsteroidal anti-inflammatory drug (NSAID) monotherapy can be used to treat musculoskeletal signs and symptoms; if clinical remission or low disease activity is not achieved within 4 weeks, a nonbiologic disease-modifying antirheumatic drug (DMARD) should be considered. (Strong recommendation).
  • Use NSAIDs before methotrexate in treatment-naive patients with less active disease and after consideration of cardiovascular and renal risks of NSAIDs.
  • Consider systemic corticosteroids but use with caution and at lowest effective dose (< 7.5 mg/day prednisone equivalent) and for short periods of time to minimize adverse effects, including psoriasis flare upon withdrawal (Weak recommendation).
  • Intra-articular corticosteroids (such as methylprednisolone acetate and triamcinolone acetonide) may be considered for treatment of patients with mild psoriatic arthritis, persistent synovitis, for bridging therapy until systemic therapy becomes effective, or as adjunct therapy especially in patients with monoarthritis or oligoarthritis (Weak recommendation).
  • Disease-modifying antirheumatic drugs (DMARDs):
    • Guidelines vary regarding the initial DMARDs used.
      • All organizations recommend nonbiologic DMARDs (methotrexate (MTX), leflunomide (LEF), or sulfasalazine (SSZ)) as an option for initial therapy (Strong recommendation).
      • More recent guidelines recommend TNF inhibitors as an option for the first-line therapy (Strong recommendation).
      • Most organizations recommend biologic therapy in patients who have had an inadequate response to nonbiologic DMARDs (Strong recommendation).
• Management of enthesitis:
  • NSAIDs are suggested as the initial treatment regimen (Weak recommendation).
  • For patients who do not respond to NSAIDs, options include:
    • physiotherapy (Weak recommendation)
    • corticosteroid injections (use with caution as injecting corticosteroids in weight-bearing entheseal sites can cause the entheses to rupture) (Weak recommendation)
    • TNF inhibitors (Strong recommendation)
    • IL-12/23i (ustekinumab) (Strong recommendation)
    • IL-17i (secukinumab) (Weak recommendation)
    • PDE-4i (apremilast) (Weak recommendation)
• Management of dactylitis:
  • Consider NSAIDs as the initial treatment regimen (Weak recommendation).
  • For patients who do not respond to NSAIDs, options include:
    • corticosteroid injections as indicated (Weak recommendation)
    • TNF inhibitors:
      • infliximab, adalimumab, golimumab, or certolizumab pegol (Strong recommendation)
      • etanercept (Weak recommendation)
    • traditional nonbiologic DMARDs (MTX, SSZ, LEF) (Weak recommendation)
    • IL-12/23i (ustekinumab) (Weak recommendation)
    • IL-17i (secukinumab) (Weak recommendation)
    • PDE-4i (apremilast) (Weak recommendation).
• Management of axial disease:
  • For biologic-naive patients, options include:
    • NSAIDs (Strong recommendation)
    • simple analgesia (acetaminophen), physiotherapy (Strong recommendation)
    • physiotherapy (Strong recommendation)
    • TNF inhibitors in patients with insufficient response to NSAIDs (Strong recommendation)
    • IL-17i (secukinumab) (Weak recommendation)
    • corticosteroid sacroiliac injections (when appropriate) (Weak recommendation)
    • bisphosphonates (Weak recommendation)
  • For patients with inadequate response to biologics, options include:
    • physiotherapy, simple analgesia (Strong recommendation)
    • NSAIDs (Weak recommendation)
    • another TNFi (Weak recommendation)
    • IL-17i (secukinumab) (Weak recommendation)
• Management of nail disease:
  • For patients with moderate-to-severe nail involvement, options include:
    • TNF inhibitors (Strong recommendation)
    • IL-12/23i (ustekinumab) (Strong recommendation)
    • IL-17i (secukinumab) (Weak recommendation)
    • PDE-4i (apremilast) (Weak recommendation)
  • For patients in whom other therapies are contraindicated or with mild nail involvement, options include:
    • topical therapies (Weak recommendation):
      • Topical therapies, including corticosteroids, salicylic acid, calcipotriene, or tazarotene, may be used alone or in combination for treatment of nail disease.
    • local corticosteroid injections (Weak recommendation)
    • nonbiologic DMARDs (cyclosporine A, LEF, acitretin, and MTX) (Weak recommendation)
• Screening for comorbidities:
  • Screen for hepatitis B, hepatitis C, HIV, and tuberculosis before initiation of DMARD therapy that may alter the immune response.
  • Patients with psoriatic arthritis are at an increased risk of comorbid conditions, including diabetes mellitus, hypertension, cardiovascular disease, and depression.
    • Consider screening for these conditions as appropriate (Weak recommendation).
    • Annual evaluation of patients with severe psoriatic arthritis should include body mass index (BMI), diabetes screening, blood pressure measurement, and lipid profile (Weak recommendation).
    • As appropriate, include psychosocial measures with referral to mental health services (Weak recommendation).
    • Patients should be encouraged to exercise regularly, maintain a healthy BMI, avoid smoking, and drink alcohol only in moderation (Weak recommendation).