Risk factors associated with having psoriatic arthritis in patients with cutaneous psoriasis

• Published in: Journal of dermatology Vol. 37; no. 5; pp. 426 - 430
• Main Authors: TEY, Hong Liang, EE, Hock Leong, TAN, Andy SL, THENG, Thiam Seng, WONG, Su Ni, KHOO, Shih Wee
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.05.2010
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Arthritis, Psoriatic - epidemiology; Arthritis, Psoriatic - ethnology; associations; Body Surface Area; Case-Control Studies; Child; Ethnic Groups - statistics & numerical data; Female; Genetic Predisposition to Disease; Humans; Male; Middle Aged; Multivariate Analysis; Odds Ratio; psoriasis; Psoriasis - epidemiology; Psoriasis - ethnology; psoriatic arthritis; Risk Factors; Singapore - epidemiology; Surveys and Questionnaires; Young Adult; Singapore
• ISSN: 0385-2407; 1346-8138
• DOI: 10.1111/j.1346-8138.2009.00745.x

The aim of this study was to determine if the following characteristics were associated with the presence of psoriatic arthritis in a sample of psoriasis patients: race, family history of psoriasis and psoriatic arthritis, age of onset of psoriasis, smoking, alcohol consumption and the maximum body surface area (BSA) affected by psoriasis. This was a case–control study involving 400 psoriasis patients who attended the Psoriasis and Photo‐medicine clinic in the National Skin Center of Singapore over a 1‐year period. Cases were psoriasis patients with psoriatic arthritis while controls were psoriasis patients without psoriatic arthritis. The diagnosis of psoriatic arthritis was made by rheumatologists and participants completed a self‐administered standardized questionnaire. The maximum BSA involved was determined from the case notes. Psoriatic arthritis was not significantly associated with sex, race, age of onset of psoriasis, a family history of psoriasis, smoking and alcohol consumption but was significantly associated with a family history of psoriatic arthritis (P < 0.001) and the maximum body surface involved (P = 0.05). Using multivariate analysis to control for variables, the presence of psoriatic arthritis was significantly associated with a family history of psoriatic arthritis (odds ratio [OR] = 20.5; 95% confidence interval [CI] = 2.49–169.10) and the maximum BSA involved (OR = 2.52; 95% CI = 1.33–4.75). Indian psoriatic patients were more likely to have psoriatic arthritis compared to the other races. A family history of psoriatic arthritis and a greater maximum body surface involved may be associated with having psoriatic arthritis in this study population of psoriasis patients.