1. Department of Dermatology, Kurume University School of Medicine, and Kurume University Institute of Cutaneous Cell Biology, 67 Asahimachi, Kurume, Fukuoka 830‐0011, Japan
2. Section of Dermatology, Kagawa Prefectural Central Hospital, 5‐4‐16 Bancho, Takamatsu‐shi, Kagawa 760‐8558, Japan
3. Department of Dermatology, Ryukyu University School of Medicine, 207 Uehara Nishiharacho, Nakagamigun, Okinawa 903‐0125, Japan
4. Social Hygiene Service, Department of Health, Cheung Sha Wan Dermatological Clinic, 3/F West Kowloon Health Centre, 303 Cheung Sha Wan Road, Kowloon, Hong Kong, China