OBJECTIVE: To determine the clinical features of psoriatic arthritis (PsA) in a multiethnic Oriental population and to study the effect of ethnicity on disease patterns.
METHODS: A retrospective study of 80 patients with PsA seen at either a rheumatology or dermatology referral center. Patients and case records were reviewed and data abstracted according to a standard protocol. Eighty consecutive patients with psoriasis without PsA seen at the dermatology center were recruited as controls.
RESULTS: Asymmetric polyarthritis developing in the 4th decade with an equal male to female ratio was the commonest pattern of arthritis among Chinese, Indians, and Malays. Clinically apparent lumbar spondylitis was significantly more common in Indians than Chinese (10/11 vs 11/20, respectively; p = 0.046), although the prevalence of lumbar spondylitis was similar in all ethnic groups. Eighty-nine percent of subjects required nonsteroidal antiinflammatory drugs and 51% required disease modifying antirheumatic drugs at some time for control of joint disease. PsA was significantly more common among Indians compared to the ethnic distribution of the Singapore population (p < 0.000001). Multiple logistic regression identified Indian ethnicity as a risk factor for the development of PsA (OR 2.39, 95% confidence interval 1.02 to 5.60).
CONCLUSION: The commonest pattern of PsA in all ethnic groups was asymmetric polyarthritis. Ethnicity affected the development and presentation of PsA in our series: Indians with psoriasis had double the risk of developing PsA compared to Chinese with psoriasis, and lumbar spondylitis when present in Chinese subjects was asymptomatic in 45%, being detectable only on radiological examination.
A prospective clinical study of 181 patients with psoriasis seen in Seremban General Hospital showed the incidence of psoriasis among dermatology outpatients was 2.15%. A significantly higher proportion of male patients were affected, with a male to female ratio of 1.7:1. Within the racial groups; 63 were Malays, 37 Chinese, and 81 Indians. There was a significantly higher proportion of Indians affected as compared with the races. The mean age of patients in this study was 43.7 years old but the mean age of onset of psoriasis in these patients was 33.1 years old. Thirty-one (17.1%) patients gave a positive family history of psoriasis and the mean age of onset of psoriasis was lower (29.3 years old) for patients with a positive family history. Plaque psoriasis was the commonest type of clinical presentation with the scalp being the commonest site affected. Psoriatic arthropathy was seen in 35 (19.3%) patients. Ninety-five (52.5%) patients gave a positive history of factors exacerbating their pre-existing disease and stress was singled out as the most common exacerbating factor.
Study site: Skin clinic, Hospital Tuanku Jaafar, Seremban, Negeri Sembilan, Malaysia
Patients with psoriasis may have increased risk of psychological comorbidities. This cross-sectional study aimed at determining associations between sociocultural and socioeconomic factors with the Depression Anxiety Stress Scale (DASS) scores and the Dermatology Life Quality Index (DLQI) scores. Adult patients with psoriasis were recruited from a Dermatology outpatient clinic via convenience sampling. Interviews were conducted regarding socio-demographic factors and willing subjects were requested to complete the DASS and DLQI questionnaires. The Pearson χ2 test, Fisher's exact test and multivariate logistic regression were used for statistical analysis to determine independent predictors of depression, anxiety, stress and severe impairment of quality of life. Unadjusted analysis revealed that depression was associated with Indian ethnicity (p = .041) and severe impairment of quality of life was associated with Indian ethnicity (p = .032), higher education (p = .013), higher income (p = .042), and employment status (p = .014). Multivariate analysis revealed that Indian ethnicity was a predictor of depression (p = .024). For stress, tertiary level of education (p = .020) was an independent risk factor while a higher monthly income was a protective factor (p = .042). The ethnic Indians and Malays were significantly more likely than the ethnic Chinese to suffer reduced quality of life (p = .001 and p = .006 respectively) and subjects with tertiary education were more likely to have severe impairment of quality of life (p = .002). Our study was unique in determining sociocultural influences on psychological complications of psoriasis in a South East Asian population. This has provided invaluable insight into factors predictive of adverse effects of psoriasis on psychological distress and quality of life in our patient population. Future studies should devise interventions to specifically target at risk groups in the development of strategies to reduce morbidity associated with psoriasis.
Study site: Dermatology clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia