Background: The Japanese Society for Psoriasis Research has conducted an annual survey of psoriasis patients in Japan from 1982 to 2001.
Objective: To perform the epidemiological study about a survey of psoriasis patients conducted in Japan for twenty years.
Methods: A sample of 28628 cases was collected from 148 dermatology centers throughout Japan. The reports from each center were analyzed.
Results: Males (65.8%) were predominant over females (34.2%) in number. The vast majority of cases (86.0%) had plaque-form of psoriasis vulgaris, and 812 cases (2.8%) showed guttate psoriasis. Psoriatic erythroderma (0.8%), generalized pustular psoriasis (0.9%), and localized pustular psoriasis (0.5%) were rare. Three hundred of the patients (1.0%) manifested psoriatic arthritis. Local corticosteroids (67.8%) were the most used modalities, whereas local vitamin D(3) preparations (2.4%) were rarely used. For photo-therapeutic treatments, topical (12.1%) and systemic (7.5%) PUVA were predominant over UVB therapy (0.5%). In systemic treatments, drugs from the herbal medicine was the first (14.2%), followed by etretinate (7.6%), nonsteroidal anti-inflammatory drugs (4.4%), oral corticosteroids (4.1%), methotrexate (2.8%), cyclosporine (1.6%), and anti-cancer drugs (1.4%).
Conclusion: This survey was the first epidemiological study throughout Japan.