Rheumatology and Dermatology Multidisciplinary Clinic Improves Diagnostic Precision and Treatment Decisions in Patients Suspected or Diagnosed with Psoriatic Arthritis.

Purpose: Psoriatic arthritis (PsA) and psoriasis (Pso) are highly heterogeneous inflammatory diseases. Multidisciplinary approaches are associated with improved results in both musculoskeletal (MSK) and skin manifestations. We describe the experience and main diagnostic and therapeutic outcomes of one of the largest and longest-running Rheumatology/Dermatology multidisciplinary PsA Clinic. Methods: Single center, cross-sectional study of all patients observed at the PsA Clinic of Hospital de Santa Maria, Portugal, between November 2010 and February 2021. The total number of visits/ patients, demographics, referral indications, and definite skin and MSK diagnosis were registered. In patients with PsA confirmed diagnosis, PsA and Pso characteristics, previous treatments and their modifications were captured using Reuma.pt. Results: Eight hundred and two visits were performed, corresponding to 505 patients, 51.3% female, with a mean age of 51.0 ± 13.8 years. The main indication for referral was diagnosis uncertainty (56.4%), and a definitive PsA diagnosis was established in 28.9% of these cases. For patients in whom PsA was not identified, the main alternative diagnoses were osteoarthritis [peripheral (n = 70) or axial (n = 29)], fibromyalgia (n = 22), axial spondylarthritis without Pso (n = 21), tendinitis/enthesitis (n = 20), and carpal tunnel syndrome (n = 19). The main alternative dermatological diagnoses were seborrheic dermatitis (n = 15), nail dystrophy not due to Pso (n = 15), onychomycosis (n = 14) and eczema (n = 9). In patients with confirmed PsA (n = 308), 54.5% had already been treated with disease-modifying antirheumatic drugs (DMARD), and 15.9% had received at least one biologic DMARD. Treatment was modified in 78.9% of PsA patients, 58.0% due to uncontrolled skin activity, 34.5% MSK activity, and 7.7% both. Most of the treatment changes occurred due to lack of efficacy (56.4%). Conclusion: This study shows the impact, through diagnostic precision (by increasing the number of psoriatic and non-psoriatic definite diagnoses), and treatment modifications, for skin and MSK manifestations, from over 10 years of the implementation of a multidisciplinary PsA Clinic.