1. Department of Dermatology; Faculty of Medicine and Graduate School of Medicine; Hokkaido University; N15 W7, Kita-ku Sapporo 060-8638 Japan
2. Department of Dermatology; JCHO Sapporo Hokushin Hospital; 2-6-2-1, Atsubetu Chuo, Atsubetu-ku Sapporo Hokkaido 004-8618 Japan