Patient characteristics, treatment patterns and disease outcomes in patients with psoriatic arthritis followed in a combined Dermatology-Rheumatology clinic: a retrospective real-world study

The aim of this study was to assess the patient characteristics, treatment patterns and disease outcomes in patients with psoriatic arthritis (PsA) referred to a combined Dermatology-Rheumatology (Derm-Rheum) Clinic. This was a retrospective study of patients seen in a combined Derm-Rheum Clinic (February 2018 to June 2020) in a Tertiary University Hospital. Consecutive patients with suspicious musculoskeletal symptoms or a known diagnosis of PsA referred to the Derm-Rheum Clinic were examined and followed simultaneously by experienced dermatologists and rheumatologists. Among 151 patients with psoriasis (PSO) with suspicious musculoskeletal complaints, 129 (85%) with a final diagnosis of PsA were included (56% females, mean age: 55 years, median disease duration: 14.2 years). In 62% of these patients (n = 94), PsA was diagnosed for the 1st time. At initial evaluation, 95% had peripheral arthritis, 45% nail involvement, 23% axial involvement, 12% enthesitis and 6% dactylitis with a median DAPSA and PASI scores of 20.5 and 1.6, respectively. 31% of the patients were not receiving any systemic treatment, 45% were on biologics, 29% on non-biologics and 10% on targeted synthetic agents (apremilast). At last visit (median interval time: 15 months), only 8% did not receive any systemic therapy (p < 0.001 compared to 1st visit), 62% were on biologics (p = 0.009 compared to 1st visit), 46% on non-biologics (p = 0.01 compared to 1st visit) and 10% remained on apremilast. The median DAPSA and PASI scores decreased significantly to 5.3 and 0, respectively. In conclusion, about 2/3 of patients with PSO and musculoskeletal complaints referred to a combined Derm-Rheum Clinic were diagnosed for the 1st time with PsA. During follow-up, the percentage of PsA patients on systemic therapies significantly increased with major improvement of disease activity indices. These data emphasize the value of combined Derm-Rheum Clinics for earlier referral, diagnosis, and more effective treatment of PsA patients.