Characteristics and Contributing Factors for Difficult to Treat Psoriatic Arthritis- a Comparative Analysis

Objective To assess the contributing factors and clinical characteristics of difficult-to-treat (D2T) psoriatic arthritis (PsA). Patients and methods This retrospective cross-sectional study included PsA patients from a tertiary care center. D2T PsA was defined as failure of at least 1 conventional synthetic DMARD (csDMARD) and 2 or more biologic/targeted synthetic DMARDs (b/tsDMARDs) with different mechanisms of action. Baseline demographics, disease duration, and domain involvement were compared across groups. Results A total of 150 PsA patients were included, with an equal gender distribution and a mean age of 55.9 ± 13.7 years. Patients with D2T PsA had a significantly younger age of onset for both psoriasis and PsA (both P < 0.001), and a higher prevalence of obesity ( P = 0.018). Multidomain involvement was prominent, with 93.5% of D2T patients having 3 or more domains affected ( P < 0.001). Axial disease, dactylitis, enthesitis, and nail involvement were all significantly more frequent in the D2T group (all P < 0.001). Multivariate analysis identified age, age of psoriasis onset, axial involvement, enthesitis, and nail dystrophy as independent predictors of D2T PsA. Conclusion D2T PsA is associated with early disease onset, obesity, and extensive multi-domain involvement, particularly axial disease, enthesitis, and nail changes. These findings suggest that specific clinical features and comorbidities may help identify patients at risk of developing D2T PsA. Early recognition of these factors may guide more personalized and aggressive treatment strategies to improve long-term outcomes.