Epidemiological analysis of psoriatic arthritis patients in Japan

Abstract

To determine the current status of psoriatic arthritis, we conducted a retrospective survey by sending questionnaires. The newly visited psoriatic arthritis patients accounted for 10.5% (95% confidence interval, 7.9-13%) of all newly visited psoriasis patients (n = 2581) between April 2014 and March 2015 in 73 institutes. Additionally, questionnaires on detailed patients' information were returned by 92 institutes (response rate, 70.8%), where 1282 patients with psoriatic arthritis were identified. There was a male predominance. The mean onset age of psoriatic arthritis was 44.9 years, and mean onset age for cutaneous psoriasis (36.4 years) was lower than that for arthritis (45.1 years). The mean duration in patients who developed psoriasis prior to arthritis was 11.2 years, while that in patients preceded by arthritis was 4.4 years. According to the Moll and Wright criteria, polyarthritis type was most common (36%), followed by distal interphalangeal type (26%) and oligoarthritis type (22%). Peripheral joint pain was 61.5%, back pain such as lumbago and neck pain was 34.3%. Enthesitis and dactylitis were observed in 28.3% and 59.2%, respectively. Biologics were used in 55.5% of psoriatic arthritis patients, and 31% used disease-modifying antirheumatic drugs. In conclusion, the ratio of psoriatic arthritis in Japan is increasing, and nearly 10% of new psoriasis patients had psoriatic arthritis. This study shows the current status of psoriatic arthritis in Japan, including several unexpected findings such as male predominance, longer duration between the onset of cutaneous psoriasis and arthritis, and dominance of polyarthritis.

Cross‐sectional multicenter observational study of psoriatic arthritis in Japanese patients: Relationship between skin and joint symptoms and results of treatment with tumor necrosis factor‐α inhibitors

“…According to a survey by Yamamoto et al, 12 10.5% of the 2581 patients with psoriasis newly attending their dermatology facilities had PsA. The frequency of PsA in this cohort was 13.5%.…”

Clinical characteristics of Japanese patients with psoriatic arthritis: Comparison with East Asian countries

“…The average duration (>10 years) was much longer than was expected. The mean disease duration was over 10 years in the group with psoriasis precedence, whereas 4.4 years in the group with arthritis precedence . Psoriasis occurred prior to the onset of arthritis in 76% of the patients, after the onset of arthritis in 5% and concurrently with arthritis in 19%.…”

“…Also, similar results were obtained in parallel inquiries involving newly visited PsA patients, which were conducted in these consecutive 3 years. The onset age of PsA between 20 and 69 years of age accounted for 94% of the patients, with a mean age of 45 years old …”

“…So far, the rate of PsA has been estimated to be much lower than it really is, which is mainly due to the lack of data. In recent years, several epidemiological studies have been conducted in Japan (Table ) . Among these studies, the survey by the JSPR is the largest one, although there are several limitations to this study, such as a non‐population‐based study, survey from dermatology departments only and a selection bias of referral centers.…”

Cardiovascular and Metabolic Diseases Comorbid with Psoriasis: Beyond the Skin

“…Approximately 15-30% of Caucasians with psoriasis eventually develop psoriatic arthritis (37). Although the prevalence is lower in Asian populations (Chinese 5.3-7.3%, Japanese 10.5% and Korean 11.2%), psoriatic arthritis significantly hampers patients' daily lives (37, 40). Additionally, psoriasis has significant comorbidity with CVD and metabolic syndrome.…”