Prevalence and Clinical Characteristic of Inflammatory Arthritis in Thai Patients with Systemic Sclerosis: A Cross-Sectional Study

Background: Systemic sclerosis is a type of autoimmune connective tissue disease. It is more prevalent in the Northern and Northeastern regions of Thailand compared to other regions, with diffuse cutaneous systemic sclerosis (dcSSc) being the most common subtype. Musculoskeletal involvement, including arthritis, is a major cause of disability and reduced quality of life in patients with systemic sclerosis. Objective: To investigate the prevalence of arthritis in patients with systemic sclerosis and define the clinical association with arthritis. Materials and Methods: The present research was an observational analytical study conducted at Sunpasitthiprasong Hospital, Ubon Ratchathani Province, Thailand, between January 2022 and January 2023. One hundred ninety-seven patients with systemic sclerosis were included in the study, and logistic regression analysis was used for investigating the clinical association with arthritis. Results: One hundred ninety-seven patients were included and comprised of 138 (70.1%) with arthritis. The majority of patients with arthritis were female, at 71.1%, and dcSSc, at 91.4%, with the mean age of 51.6±11.8 years. Multivariable logistic regression analysis after controlling for other variables revealed that periarticular osteopenia was significantly associated with arthritis in patients with systemic sclerosis (95% confidence interval: 8.34 to 67.36). Conclusion: Arthritis was a common clinical feature in systemic sclerosis for 70.1%. The presence of periarticular osteopenia was independently associated with arthritis. This clinical factor could be utilized to aid in the diagnosis of arthritis in systemic sclerosis patients and improve treatment outcomes.