Objectives The aim of the study was to analyse baseline clinical patterns of early psoriatic arthritis (PsA), and to compare this patterns with early rheumatoid arthritis (RA) both from an early arthritis clinic (EAC). As a secondary objective we analysed differences in outcomes and therapy.

Methods We studied 1102 patients from our EAC and included all patients who were diagnosed as PsA or RA after 2 years follow-up. We collected demographic and clinical characteristics at baseline as: joint involvement, symmetry, sex, age and smoking habit. Clinical and laboratory assessments included morning stiffness, joint pain, patient and physician global assessment (PtGA, PhGA), tender (TJC) and swollen joint count (SJC), HAQ, DAS28, SDAI, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), anti-citrullinated peptide antibodies (ACPA) and therapy

Results Sixty-four patients with a final diagnosis of PsA were included and were compared with 483 patients with a definite diagnosis of RA. Thirty-five patients (54.7%) were male and the mean age was 56.5±13.2 years. The initial pattern was oligoarticular, polyarticular and monoarticular in 50%, 36% and 14% of patients, respectively. Most of them had a subacute onset (53, 82.8%) and 11 (18.2%) had an acute onset. Joint involvement was symmetrical or asymmetrical in similar percentages.

At baseline, PsA patients have more frequently a mono or oligoarticular pattern as compared to RA (64% vs 18%, respectively, p<0.01) and were less frequently symmetrical (51.5% vs 88%, p<0.01). Less PsA patients were women (45.3% vs 78% p<0.01) and were younger (56±13.2 vs 61.3±17.7 years, p<0.01). No differences in smoking habit or the type of involvement (acute vs subacute) were found. Clinical characteristics at baseline and after 2 years follow-up are shown in table.

There were significant differences in ACCP and RF between both groups, without differences in ESR and CRP. A lower percentage of PsA patients used Methotrexate as compared to RA patients (75% vs. 90.4%, p<0.01), and a higher percentage used sulfasalazine (15.6% versus 7.4% p=0.05), mainly in patients with axial involvement, with no differences in the use of leflunomide.

Conclusions In this early arthritis cohort of PsA patients, clinical involvement at baseline was significantly different from RA patients. Disease activity and disability was lower in patients with PsA as compared with RA both at baseline and after 2 years follow-up.

Disclosure of Interest None declared