RT Journal Article SR Electronic T1 Prevalence and Clinical Characteristics of Psoriatic Arthritis in Japan JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP jrheum.141598 DO 10.3899/jrheum.141598 A1 Yuri Ohara A1 Mitsumasa Kishimoto A1 Naoho Takizawa A1 Kazuki Yoshida A1 Masato Okada A1 Hikaru Eto A1 Gautam A. Deshpande A1 Christopher T. Ritchlin A1 Atsushi Tanaka A1 Mari Higashiyama A1 Kazuo Matsui A1 Shigeyoshi Tsuji YR 2015 UL http://www.jrheum.org/content/early/2015/06/11/jrheum.141598.abstract AB Objective To investigate the prevalence of psoriatic arthritis (PsA) in Japanese patients with psoriasis. Methods A multicenter, noninterventional, retrospective cross-sectional study was conducted at 3 tertiary care centers in Japan. PsA was diagnosed by rheumatologists based on clinical findings. Prevalence of PsA, clinical characteristics, comorbidities, and treatment patterns were examined. Results PsA was identified in 431 of 3021 patients with psoriasis, with a mean prevalence of 14.3% (range, 8.8–20.4%). No large differences between these results and previous reports from Western countries were observed in arthritis distribution, skin disease type, or treatment selection. Conclusion The prevalence of PsA in patients with psoriasis in Japan approaches 20% in some areas, similar to that observed in Western countries, and is higher than previously reported in Asia. Clinical features including age, sex, age at onset, and manifestation patterns were also similar to those reported in the West.