The spectrum of psoriatic arthritis in a South African cohort

The aim of this study was to describe the clinical features of patients with psoriatic arthritis (PsA) in a South African cohort. This is a retrospective analysis of patients contributing to development of the international classification criteria for PsA, ClASsification criteria for Psoriatic ARthritis (CASPAR). Patients were all seen at the arthritis clinics at Groote Schuur Hospital, Cape Town. Demographic, clinical, laboratory and radiographic information was collected. This study describes the relevant findings relating to the clinical profile of the patients seen at our centre as well as the effect of family history and/or dactylitis in determining the severity of psoriatic arthritis. There were 45 patients with a male to female ratio of 1:1.25. The mean age of psoriasis onset was 38.34 years (SD 15.54), whilst that of arthritis onset was 43.86 years (SD 13.4). Polyarthritis was the commonest pattern and sacro-iliitis was uncommon. Dactylitis was present in 26%. The presence of family history or of dactylitis did not predict more severe disease. There was a significant correlation between tender and swollen joints. The mean Health Assessment Questionnaire (HAQ) score was 1.05. Eighty-three percent showed evidence of radiological changes, and distal interphalangeal (DIP) erosions were found in 54%. Arthritis mutilans was present in 31%. There were no black subjects in the cohort. The clinical patterns of PsA in our cohort are similar to those reported elsewhere. The paucity of blacks amongst this cohort requires further study. PsA-specific measures of disease activity need to be developed. PsA causes significant joint damage and disability.