1. Department of Dermatology; Hokkaido University Graduate School of Medicine; North 15 West 7, Kita-ku Sapporo 060-8638 Japan
2. Department of Dermatology; JR Sapporo Hospital; Sapporo Japan
3. Department of Dermatology; Japan Community Health Care Organization; Sapporo Hokushin Hospital; Sapporo Japan
4. Department of Dermatology; Sapporo City General Hospital; Sapporo Japan