Background Psoriatic arthritis (PsA) is an inflammatory joint disease with variable clinical presentations. One of these presentations is axial involvement. For this reason, PsA is included within the peripheral spondyloarthritis. Several diagnosis and classification criteria for PsA have been proposed. The CASPAR and ASAS criteria are being implemented progressively in rheumatology. There is some controversy about its usefulness, especially regarding the ASAS criteria for peripheral involvement as these criteria were not designed for use in patients with PsA. There are few publications relating ASAS criteria with PsA and their correlation with CASPAR crtieria

Objectives The main objective was to determine the correlation between the presence of CASPAR criteria and ASAS criteria for peripheral involvement (pASAS). Secondary objectives were: (a) to establish the percentage of patients diagnosed with PsA who met CASPAR and pASAS criteria; (b) to determine what percentage of patients meeting CASPAR criteria also met pASAS criteria.

Methods In a multicenter cross observational study, 292 adult patients diagnosed with PsA were recruited in different hospitals of the Region of Murcia (mean age 53.25 years; 56.2% men; average PsA duration 7,02 years). Diagnosis was made by experienced rheumatologists. The percentage of patients meeting CASPAR and pASAS criteria was determined and a chi-square test was done to stablish the correlation between both criteria

Results Of the 292 patients studied, 268 (91.8%) met CASPAR criteria and 221 (75.7%) pASAS criteria. For all the patients with CASPAR criteria, 79.1% also met pASAS criteria. The comparison of both criteria with the chi-square test gave a result of 20.7 with a p-value <0.0001.

Conclusions We can establish that within the study population of patients with PsA, there is a significant association between CASPAR and pASAS criteria. A higher percentage of patients with a diagnosis of PsA made by an experienced rheumatologist met CASPAR criteria (91.8%). pASAS criteria were present in a lower percentage of patients (75.7%), increasing slightly among patients meeting also CASPAR criteria (79.1%)

References

1. JC Torre Alonso. Use and application in clinical practice of the CASPAR criteria. Reumatol Clin 2010;6(S1):18–21.

2. Rosaline van den Berg, Floris van Gaalen, Annette van der Helm-van Mil, et al. Performance of classification criteria for peripheral spondyloarthritis and psoriatic arthritis in the Leiden early arthritis cohort. Ann Rheum Dis 2012;71:1366–1369.

3. Coates LC, Conaghan PG, Emery P, et al. Sensitivity and Specificity of the Classification of Psoriatic Arthritis Criteria in Early Psoriatic Arthritis. Arthritis Rheum 2012;64: 3150-3155.

Disclosure of Interest None declared