Background Psoriatic Arthritis (PsA) may affect up to 40% of patients with psoriasis (PsO). Usually PsO precedes PsA for many years, though PsA is frequently not identified in dermatology clinics. Diagnosis of PsA is based on clinical recognition of arthritis, enthesitis and spondylitis.
Objectives To determine the prevalence of PsA in a large cohort of Brazilian patients with PsO attending different dermatology reference centers.
Methods A multicenter study was conducted in four universitary dermatology clinics, from January to March 2011. In each center, consecutive patients with a confirmed diagnosis of PsO were evaluated by a rheumatologist. Following detailed musculoskeletal anamnesis and physical examination, subjects were classified as having: isolated PsO, osteoarthritis (OA) and/or chronic myofascial pain (CMP) syndrome, PsA (CASPAR criteria1). Laboratory and x-Ray tests were performed, as needed, according to the rheumatologist clinical judgment.
Results A total of 524 PsO patients were evaluated. Mean age was 48.5 ± 14.5yrs, 50% were females and PsO mean duration was 15.4±11.7yrs. The vast majority (79%) had plaque psoriasis and 57.8% required systemic treatment. Isolated PsO was the diagnosis in 45% of patients, whereas 22% manifested OA and/or CMP. A definitive diagnosis of PsA was documented in 175 patients (33%), of which 49% were newly identified by the rheumatologist. Lab and/or x-Ray tests were necessary for the diagnosis of PsA in 42/175 individuals. In 38/175 subjects, PsA was associated with OA and/or CMP. Most PsA patients (72%) had peripheral, 11% axial and 17% both peripheral and axial involvement. Dactilitis occurred in 20% and clinical enthesitis in 30%. Remarkably, PsA patients were older (51 vs 47yrs, p 0.015), had more nail involvement (59 vs 47%, p 0.008), were less likely to be on any systemic treatment (42 vs 56%, p 0.01) and were more frequently using biologic drugs (21 vs 5%, p>0.001) compared with those without PsA.
Conclusions We have demonstrated a similar worldwide prevalence of 1/3 of PsA among Brazilian patients with PsO. The identification of new PsA diagnosis by a rheumatologist in half of patients, previously unrecognized at the dermatology setting, points out to the need for shared care between dermatologists and rheumatologists in order to establish earlier PsA diagnosis and adequate multidisciplinary management.
Taylor W, Gladman D, Helliwell P et al. Classification criteria for psoriatic arthritis: development of new criteria from a large international study. Arthritis Rheum 2006; 54:2665–73
Disclosure of Interest None Declared