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

Treatment of Psoriatic Arthritis

For treatment-naïve patients with active psoriatic arthritis, initiate a TNF inhibitor (adalimumab, etanercept, or infliximab) as first-line therapy unless severe psoriasis, contraindications to TNF inhibitors, or patient preference for oral therapy exists. 1

Initial Treatment Selection Algorithm

For Patients WITHOUT Severe Psoriasis (PASI <12 or BSA <10)

First-line: TNF Inhibitor

• Adalimumab 40 mg subcutaneously every other week 2
• Etanercept 50 mg subcutaneously weekly 3
• Infliximab (dosing per protocol) 1
• TNF inhibitors reduce signs and symptoms, inhibit radiographic progression, and improve physical function 4
• Can be used as monotherapy or combined with methotrexate at reduced doses (10-15 mg weekly) 5

Alternative first-line if contraindications to TNF inhibitors exist:

• Oral small molecule DMARDs, with methotrexate 15-25 mg weekly with folic acid supplementation preferred when clinically relevant skin involvement is present 5, 1
• Sulfasalazine or leflunomide have Level A evidence for peripheral arthritis 4, 5

For Patients WITH Severe Psoriasis (PASI ≥12 and BSA ≥10)

First-line: IL-17 or IL-12/23 Inhibitors

• These agents are preferred over TNF inhibitors when severe psoriasis coexists 1
• IL-12/23 inhibitors offer less frequent administration and are particularly preferred if concomitant inflammatory bowel disease exists 1

Special Population Considerations

Patients with concomitant diabetes:

• Use sulfasalazine or leflunomide instead of methotrexate due to higher risk of fatty liver disease and hepatotoxicity 5

Patients preferring oral therapy:

• Oral small molecules are appropriate when disease is not severe 5
• Methotrexate remains the preferred conventional DMARD 1

Patients with frequent serious infections or contraindications to biologics:

• Oral small molecules are strongly recommended over biologics 5
• Contraindications include congestive heart failure, demyelinating disease, or recurrent infections 5

Treatment Escalation for Inadequate Response

After Oral Small Molecule Failure

Switch to TNF inhibitor over another oral small molecule, IL-17 inhibitor, or IL-12/23 inhibitor if active PsA persists despite adequate trial (>3 months, with >2 months at standard target dose) 4, 1

Exception: Consider IL-17 or IL-12/23 inhibitors instead if severe psoriasis is present 1

After TNF Inhibitor Failure

• Consider switching to IL-17 inhibitor or IL-12/23 inhibitor 1
• If concomitant active IBD exists, prefer IL-12/23 inhibitor 1

Disease-Specific Treatment Approaches

Peripheral Arthritis

• Mild disease: NSAIDs for symptomatic relief, though they do not prevent structural joint damage 4, 5
• Intra-articular glucocorticoid injections for persistently inflamed joints, avoiding injection through psoriatic plaques 5
• Moderate to severe disease: Initiate DMARDs rapidly, progressing to TNF inhibitors if inadequate response 5

Axial Disease

• First-line: NSAIDs and physiotherapy 4, 6
• Traditional oral DMARDs (methotrexate, leflunomide, sulfasalazine) are NOT effective for axial manifestations and should not be used 4, 6
• Second-line: TNF inhibitors for moderate to severe spinal disease with insufficient response to NSAIDs 6
• Consider IL-17 inhibitor if relevant skin involvement coexists with axial disease 6
• Monitor using BASDAI score; active disease defined as BASDAI >4, treatment response as BASDAI <3 or reduction by 2 points after 6 weeks 4, 6

Enthesitis and Dactylitis

• First-line: NSAIDs and local measures 5
• Resistant cases: Progress to DMARDs 5
• Severe or refractory cases: Consider TNF inhibitors 5

Critical Safety Considerations

Before Initiating TNF Inhibitors

Mandatory screening:

• Test for latent tuberculosis before and during therapy; initiate treatment for latent TB prior to TNF inhibitor use 2, 3
• Consider empiric anti-fungal therapy in patients at risk for invasive fungal infections who develop severe systemic illness 2, 3
• Complete age-appropriate vaccinations prior to initiating treatment 3

Medications to AVOID

• Systemic corticosteroids are NOT typically recommended due to potential for post-steroid psoriasis flare 4
• Gold salts, chloroquine, and hydroxychloroquine are NOT recommended for PsA 4

High-Risk Scenarios

• Lymphoma and other malignancies, some fatal, have been reported in children and adolescents treated with TNF blockers 2, 3
• Hepatosplenic T-cell lymphoma risk is particularly elevated in adolescent and young adult males with IBD receiving TNF blockers plus azathioprine or 6-mercaptopurine 2

Treatment Goals and Monitoring

Primary goal: Achieve remission or minimal/low disease activity through regular monitoring and appropriate treatment adjustment 1

Assessment tools:

• DAS28, EULAR response criteria, or ACR20/50/70 for peripheral arthritis 4
• BASDAI for axial disease 4, 6
• Radiographic assessment for joint damage progression 4

Poor prognostic factors requiring aggressive treatment:

• Polyarticular disease 4, 5
• Elevated inflammatory markers (ESR) 4, 5
• Previous treatment failures 5
• Existing joint damage 4, 5
• Diminished quality of life 4, 5

Adjunctive Non-Pharmacologic Interventions

• Smoking cessation strongly recommended for all patients 5
• Low-impact exercise (tai chi, yoga, swimming) preferred over high-impact exercise 5
• Weight loss in overweight or obese patients may potentially increase pharmacologic response 5
• Physical therapy as first-line intervention for axial disease to improve function and reduce pain 6

Comorbidity Management

Account for comorbidities when selecting treatment:

• Cardiovascular disease 1, 6
• Metabolic syndrome 1, 6
• Depression 1, 6
• Inflammatory bowel disease (prefer IL-12/23 inhibitors) 1