What is the relationship between Rheumatoid Arthritis (RA), proctitis, and Psoriatic Arthritis (PsA)?

From the Guidelines

Rheumatoid arthritis, proctitis, and psoriatic arthritis are interconnected inflammatory conditions that require a multidisciplinary treatment approach, prioritizing shared decision-making between the patient and rheumatologist, as emphasized in the 2023 EULAR recommendations 1.

Overview of Conditions

These conditions can coexist in some patients due to shared immune system dysregulation. Rheumatoid arthritis primarily affects joints, causing symmetric inflammation, while psoriatic arthritis occurs in about 30% of psoriasis patients and presents with asymmetric joint involvement and characteristic nail changes. Proctitis, inflammation of the rectum, can develop as an extraarticular manifestation in both conditions or as part of inflammatory bowel disease, which has associations with these arthritides.

Treatment Approach

Treatment typically involves a multidisciplinary approach with immunomodulatory medications like methotrexate (starting at 7.5-15mg weekly), TNF inhibitors (adalimumab, etanercept, infliximab), or JAK inhibitors (tofacitinib, baricitinib) 1. For proctitis, topical mesalamine suppositories (1g daily) or hydrocortisone foam may provide relief. NSAIDs can help manage joint pain but may worsen intestinal inflammation in some patients.

• Key considerations in treatment include:
  • Shared decision-making between patient and rheumatologist
  • Multidisciplinary management for complex cases
  • Treatment goals: control of signs and symptoms, prevention of structural damage, normalization or preservation of function, avoidance of toxicities, and minimization of comorbidities 1
  • Patient preferences and values play a significant role in treatment decisions, including the consideration of treat-to-target approaches and the potential impact on quality of life and social participation 1

Pathophysiological Mechanisms

These conditions share pathophysiological mechanisms involving overactive immune responses with elevated pro-inflammatory cytokines like TNF-alpha and IL-17, explaining why treatments targeting these pathways can address multiple manifestations simultaneously. Regular monitoring of both joint and gastrointestinal symptoms is essential, as flares in one condition may coincide with or trigger exacerbations in the others.

• Monitoring should include:
  • Joint symptoms and disease activity
  • Gastrointestinal symptoms and disease activity
  • Patient-reported outcomes and quality of life measures
  • Adjustments to treatment based on disease activity and patient response, as part of a treat-to-target approach 1

From the Research

Relationship Between Rheumatoid Arthritis, Proctitis, and Psoriatic Arthritis

• There is no direct evidence in the provided studies that discusses the relationship between rheumatoid arthritis, proctitis, and psoriatic arthritis.
• However, the studies do discuss the similarities and differences between rheumatoid arthritis (RA) and psoriatic arthritis (PsA) 2, 3, 4, 5.
• Rheumatoid arthritis and psoriatic arthritis are both chronic inflammatory diseases that affect multiple organ systems, including the skin and joints 3, 4, 5.
• Psoriatic arthritis is frequently undiagnosed and/or misdiagnosed due to its similarities in clinical presentation with other arthritic diseases, including rheumatoid arthritis and osteoarthritis 3.
• The pathophysiology of psoriasis, psoriatic arthritis, and rheumatoid arthritis involves chronic inflammation mediated by pro-inflammatory cytokines, but there are significant differences between the three diseases at the clinical, anatomical, microscopic, and molecular levels 4, 5.
• One study discusses the incidence of urinary tract infections in patients with rheumatoid arthritis, but does not mention proctitis or psoriatic arthritis 6.

Key Differences Between Rheumatoid Arthritis and Psoriatic Arthritis

• Rheumatoid arthritis and psoriatic arthritis have different clinical manifestations, biomarkers, and radiologic features 3, 4, 5.
• Psoriatic arthritis is characterized by skin and joint manifestations, while rheumatoid arthritis is characterized by joint inflammation and damage 3, 4, 5.
• The two diseases also have different responses to specific therapies and potentially different disease outcomes and prognoses 4, 5.

Medication Adherence and Persistence

• Medication adherence and persistence are crucial for better quality of life and improved outcomes in rheumatoid arthritis, psoriasis, and psoriatic arthritis 2.
• Biologic adherence and persistence rates in RA, PsO, and PsA in the United States were found to be low, with significant opportunity for improvement 2.
• Factors associated with lower adherence and persistence rates include younger age, female gender, higher out-of-pocket costs, greater disease severity, and more comorbidities 2.