A clinical and radiographic comparison of patients with psoriatic arthritis from different ethnic backgrounds

Objectives There are few papers concerning ethnic differences in disease expression in PsA, which may be influenced by a number of genetic, lifestyle and cultural factors. This article aims to compare clinical and radiographic phenotypes in people of South Asian (SA) and North European (NE) origin with a diagnosis of PsA. Methods This was a cross-sectional observational study recruiting patients of SA and NE origin from two hospitals in a well-defined area in the North of England. Results A total of 58 SA and 48 NE patients were recruited. SA patients had a more severe clinical phenotype with more tender (median 5 vs 2) and swollen (median 1 vs 0) joints, more severe enthesitis (median 3 vs 1.5), more patients with dactylitis (24% vs 8%), more severe skin disease (median PASI 2.2 vs 1) and worse disease activity as measured by the composite Psoriatic Arthritis Disease Activity Score (mean 4.5 vs 3.6). With regards to patient-completed measures, SA patients had worse impact with poorer quality of life and function (mean HAQ 0.9 vs 0.6; mean PsAQoL 10.8 vs 6.2; mean 36-item short form physical component score 33.5 vs 38.9). No significant differences in current MTX and biologics use were found. Conclusions SA patients had a worse clinical phenotype and worse impact of disease than NE patients. Further studies are needed to confirm and explore the reasons behind these differences.