What is the treatment for psoriatic arthritis on the toes?

Treatment of Psoriatic Arthritis Affecting the Toes

For psoriatic arthritis affecting the toes, initiate NSAIDs first for symptom control, then rapidly escalate to a conventional synthetic DMARD (methotrexate preferred if skin involvement present, otherwise sulfasalazine or leflunomide) for moderate-to-severe disease, and advance to a TNF inhibitor if inadequate response after 3 months of DMARD therapy at target dose. 1

Initial Treatment Strategy

Mild Disease (Monoarticular or Oligoarticular Toe Involvement)

• Start with NSAIDs as first-line therapy for controlling joint symptoms and inflammation 1
• Add intra-articular glucocorticoid injections for persistently inflamed joints, but avoid injecting through psoriatic plaques to prevent infection risk 1, 2
• Consider initiating a csDMARD early if poor prognostic factors are present, including: structural damage on imaging, elevated ESR/CRP, dactylitis (sausage digit), or nail involvement 1

Moderate-to-Severe Disease (Polyarticular Involvement)

• Initiate a csDMARD rapidly rather than waiting for NSAID failure 1, 3
• Methotrexate is the preferred first-line DMARD when relevant skin involvement coexists with arthritis (Level B evidence) 1, 3
• Sulfasalazine or leflunomide are alternatives with Level A evidence for peripheral arthritis 1
• Ciclosporin has Level B evidence but should be limited to less than 12 consecutive months due to cumulative nephrotoxicity 1, 3

Escalation to Biologic Therapy

When to Advance to TNF Inhibitors

• Progress to a TNF inhibitor after failing at least one csDMARD trial defined as: treatment for >3 months with >2 months at standard target dose, unless significant intolerance or toxicity occurs 1
• Consider TNF inhibitors earlier (even without DMARD failure) in patients with poor prognostic factors: polyarticular disease, elevated inflammatory markers, existing joint damage, or diminished quality of life 1, 3
• All three TNF inhibitors (etanercept, infliximab, adalimumab) are equally effective for peripheral arthritis and inhibiting radiographic progression (Level A evidence) 1, 4, 5

Alternative Biologic Options

• IL-17 inhibitors or IL-12/23 inhibitors may be preferred when there is relevant skin involvement alongside peripheral arthritis 1
• JAK inhibitors may be considered after inadequate response to at least one csDMARD and at least one bDMARD, or when a bDMARD is not appropriate 1

Special Considerations for Toe Involvement

Dactylitis (Sausage Toe)

• Dactylitis occurs in 16-48% of PsA cases and represents synovitis, tenosynovitis, and enthesitis with soft-tissue edema 1
• Acute dactylitis is a clinical indicator of disease severity and warrants more aggressive treatment 1
• Treatment is largely empirical but follows the same escalation pathway: NSAIDs → DMARDs → TNF inhibitors for resistant cases 1

Hand/Foot Psoriasis

• For hand/foot psoriasis with arthritis, consider topical PUVA, acitretin (soriatane), or systemic therapy as preferable first-line agents, though more research is needed 1

Critical Safety Warnings

Avoid Systemic Corticosteroids

• Systemic corticosteroids are NOT recommended for chronic use in psoriasis due to potential post-steroid psoriasis flare and other adverse effects (Level I evidence) 1, 6
• Local glucocorticoid injections may be used judiciously but systemic therapy should be avoided 1, 6

Tuberculosis Screening

• Test all patients for latent TB before initiating TNF inhibitors using tuberculin skin test (TST ≥5 mm considered positive in immunosuppressed patients) 2, 4
• Initiate isoniazid 300 mg daily for 9 months at least 1 month before starting biologic therapy when latent TB is detected 2

Treatment Monitoring

Defining Treatment Failure

• A patient is considered a treatment failure when, despite therapy for an appropriate duration at adequate dose, they fail to demonstrate acceptable clinical improvement 1
• DMARD failure is defined as inadequate response after >3 months treatment with >2 months at standard target dose 1
• Response may be inadequate if there is evidence of progression of joint damage on radiographs 1

Treatment Goals

• Aim for remission or low disease activity through regular disease activity assessment and appropriate therapy adjustment 1
• The primary goal is maximizing health-related quality of life through symptom control, prevention of structural damage, normalization of function, and social participation 1

Common Pitfalls to Avoid

• Do not use gold salts, chloroquine, or hydroxychloroquine as they are not recommended for PsA and may cause progression of skin lesions 1
• Do not inject glucocorticoids through psoriatic plaques due to infection risk 2
• Do not delay DMARD initiation in moderate-to-severe disease, as early treatment has potential to slow disease progression 1
• Do not continue inadequate therapy beyond 3 months at target dose; escalate promptly to preserve joint integrity 1