Prevalence of Psoriatic Arthritis in Nagano Prefecture, Japan, and Efficacy of the Psoriasis Epidemiology Screening Tool: A Real-World Survey

Prevalence of Psoriatic Arthritis in Nagano Prefecture, Japan, and Efficacy of the Psoriasis Epidemiology Screening Tool: A Real-World Survey

Maureen Tania Meling,¹ Eisaku Ogawa,¹ Yuki Sato,¹ Akane Minagawa,¹ Yukiko Kiniwa¹ and Ryuhei Okuyama¹

¹Department of Dermatology, Shinshu University School of Medicine, Matsumoto, Nagano, Japan

Pain, stiffness, and swelling are the main joint symptoms of psoriatic arthritis (PsA); however, they are also common symptoms of other joint diseases. Therefore, it is challenging to distinguish PsA from other joint diseases. To evaluate the prevalence of PsA and the frequency of joint symptoms in psoriasis patients, we conducted a prefecture-wide survey using the Psoriasis Epidemiology Screening Tool (PEST), a patient questionnaire for screening PsA to assess joint symptoms. Data were collected from 764 psoriasis patients, all of whom visited hospitals (55.1%) or clinics (44.9%) in Nagano Prefecture, Japan. The proportion of psoriasis patients with PsA was 6.5% (50 of 764); four patients (1.2%) with PsA were treated in clinics, while 46 patients (10.9%) were treated in hospitals. Based on the responses to the PEST, 18.1% of patients with psoriasis had joint symptoms. In contrast, 73.2% of psoriasis patients with joint symptoms did not have PsA. The PEST showed 52% sensitivity and 93.4% specificity for PsA. In addition, fingernail alterations were common in PsA. The proportion of the population with PsA was lower than reported previously in Japan. This may have been due to the enrollment of a large number of patients treated in clinics. Many patients with PsA were treated at hospitals, which likely reflects the tendency of patients with joint symptoms to receive intensive treatment in hospitals. In addition, based on the lower sensitivity of the PEST in this study, further studies are necessary to establish the validity of the PEST.

Keywords —— fingernail alterations; joint symptoms; psoriasis; Psoriasis Epidemiology Screening Tool (PEST); psoriatic arthritis

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Tohoku J. Exp. Med 2022, 257, 205-210.

Correspondence: Ryuhei Okuyama, Department of Dermatology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan.

e-mail: rokuyama@shinshu-u.ac.jp