1. Department of Dermatology; Sapporo City General Hospital; North 11, West 13, Chuo-ku Sapporo 060-8604 Japan
2. Department of Dermatology; Iwamizawa Municipal General Hospital; 2, 9 jo, West 7 Iwamizawa 068-8555 Japan
3. Department of Dermatology; Hokkaido University Graduate School of Medicine; North 15, West 7, Kita-ku Sapporo 060-8638 Japan