Phenotypic and clinical differences between Caucasian and South Asian patients with psoriatic arthritis living in North East London.

To test for demographic and clinical differences between Caucasian and South Asian patients with psoriatic arthritis (PsA) living in the same environment and for differences between sexes. The demographic characteristics of patients attending outpatient clinics were obtained using a semi-structured questionnaire. Clinical parameters included disease activity (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), erythrocyte sedimentation rate (ESR), C-reactive protein), function (Bath Ankylosing Spondylitis Functional Index (BASFI)) and visual analogue scale (VAS) scores for well-being and night pain (10 cm, where 10 = worst possible response). The first symptom experienced at disease onset and the main symptoms during the disease course were recorded in the questionnaire. A total of 217 patents were assessed of whom 151 were Caucasians and 66 were Asians. South Asian patients were significantly younger [(mean) 45.9 years [(SD)(±11.4)] for Asians and 53.1 years (±14.2) for Caucasians (p < 0.005)] and were diagnosed at an earlier age [40.7 years (±11.7) for Asians and 46.7 years (±15.8) for Caucasians (p < 0.05)] compared to Caucasians patients. Asian females with PsA had worse disease in terms of activity (ESR = 23.9 mmHg/h; BASDAI = 6.7), function (BASFI = 5.5), night pain (7.1 on VAS) and well-being (6.6 on VAS) compared with Asian males (13.2 mmHg/h, 5.3, 3.6, 4.1, 4.6, respectively) or Caucasian males and females (15.8 mmHg/h, 5.9, 5.3, 5.4, 5.4; 18.9 mmHg/h, 6.1, 6.1, 5.3, 5.8, respectively). There were no significant differences in symptoms at disease onset or the main symptoms during the disease course between Caucasian and Asian patients, although there was a trend towards more frequent enthesitis in Asian females during the course of disease suggested by pain with pressure compared to Asian males. South Asian patients may develop PsA earlier in life than Caucasian patients do, but their clinical characteristics are generally similar. Asian females with PsA have worse disease activity, function, night pain and well-being than Asian males and Caucasian males and females.