Analysis of psoriatic patients registered in Asahikawa Medical College Hospital from 1983 to 2007

Abstract

Psoriasis is a chronic inflammatory skin disease, which has been increasing during the last 50 years in Japan. The aim of the present study is to analyze psoriatic patients registered from 1983-2007 in Asahikawa Medical College Hospital, which is located in the northern part of Japan. A total of 607 cases were registered at the first inspection in the Department of Dermatology, Asahikawa Medical College. Men (403 cases, 66.4%) were predominant over women (204 cases, 33.6%). The clinical types of psoriasis were psoriasis vulgaris (91.5%), guttate psoriasis (4.2%), psoriasis arthropathica (2.8%), psoriatic erythroderma (0.6%), generalized pustular psoriasis (0.6%), localized pustular psoriasis (0.15%) and infantile psoriasis (0.15%). Topical corticosteroids (78.1%) and vitamin D3 (18.1%) products were the main previous topical agents. Previous systemic treatments included etretinate (7.7%), cyclosporine (1.5%) and methotrexate (0.3%). Use of topical vitamin D3 and cyclosporine therapies have been gradually increasing during the past 25 years. Regarding the previous phototherapy, topical psoralen and ultraviolet A therapy (PUVA) (4.9%) was predominant over ultraviolet B (0.9%), and systemic PUVA (0.7%). Use of ultraviolet B phototherapy has been increasing during the past 5 years. The results are essentially similar to those of a survey of psoriasis in Japan from 1982-2001. Although the incidence of psoriasis might be higher in Hokkaido Prefecture, there is essentially no variation in the disease profile of psoriatic patients.

Analysis of psoriasis patients registered with the Japanese Society for Psoriasis Research from 2002-2008

“…Although the male/female ratio of psoriasis is equal in Caucasians, 5,6 our study revealed that the male incidence (7738) is approximately twice that of female (3894), confirming previous results in Japan 4,7 . The male predominance was also reported in North India and Taiwan 8,9 .…”

Variants at HLA-A, HLA-C, and HLA-DQB1 Confer Risk of Psoriasis Vulgaris in Japanese

“…In summary, imputation-based HLA fine-mapping analysis demonstrated that the PsV risk of MHC could be explained by combinations of the multiple class I and class II HLA genes in the Japanese population (HLA-C*06:02, HLA-A*02:07 [i.e., HLA-A Cys99], and HLA-DQb1 Asp57). A multivariate full regression model including these risk variants (Table 2) explained 3.6% of the overall PsV risk in the population under the assumption of 0.2% of disease prevalence (Kubota et al, 2015;Naito et al, 2016;Takahashi et al, 2009). As expected, the impact of HLA-C*06:02 (0.54%) was relatively smaller than those of HLA-A*02:07 and HLA-DQb1 Asp57 (1.3% and 1.8%, respectively).…”

“…From this perspective, the Japanese population has unique characteristics. PsV prevalence in Japan is one of the lowest compared with worldwide populations (0.1e0.3%) (Kubota et al, 2015;Naito et al, 2016;Takahashi et al, 2009), and the frequency of HLA-C*06:02 is almost rare within the Japanese population (<0.5%) (Mabuchi et al, 2014). This may suggest that the Japanese patients with PsV have a higher proportion of HLA-C*06:02negative individuals; thus, genetic studies investigating the Japanese population could contribute to unveiling novel genetic architecture associated with PsV.…”

Epidemiology and treatment of psoriasis: a Chinese perspective

“…9,11,12 The incidence of psoriasis vulgaris and pustular psoriasis in the People's Republic of China is similar to that reported in Japan (Table 3), while psoriasis arthropathica and erythrodermic psoriasis are slightly higher. 18,19 Compared to the high incidence of psoriasis arthropathica in Caucasians, accounting for 30% of psoriasis incidence, 20 the incidence of psoriasis arthropathica in Chinese patients is lower. It is also lower in Middle-Eastern and other Asian countries.…”

“…12 Other studies showing a male predominance for psoriasis have been reported in Chinese and Japanese studies. [17][18][19] Types Chinese studies show that psoriasis vulgaris accounts for 82.6%-97.9% of psoriasis patients (Table 2). Pustular psoriasis, psoriasis arthropathica, and erythrodermic psoriasis account for 0.69%-2.17%, 0.69%-6.52%, and 0%-8.7%, respectively.…”