1. Department of Preventive Medicine Korea University College of Medicine Seoul Korea
2. Department of Dermatology, Soonchunhyang University Seoul Hospital Soonchunhyang University College of Medicine Seoul Korea
3. Department of Dermatology, Soonchunhyang University Cheonan Hospital Soonchunhyang University College of Medicine Cheonan Korea
4. Department of Dermatology, Soonchunhyang University Bucheon Hospital Soonchunhyang University College of Medicine Bucheon Korea