1. Departments of Dermatology, National Defense Medical College, 3‐2 Namiki, Tokorozawa, Saitama 359, Japan,
2. Tokyo Metropolitan Ohkubo Hospital, 2‐44‐1 Kabuki‐cho, Shinjuku, Tokyo 160, Japan,
3. Doai Kinen Hospital, 2‐1‐11 Yokozuna, Sumida, Tokyo 130, Japan