1. Department of Education, Yonsei University, Seoul, Korea.
2. Department of Dermatology, School of Medicine, Kyungpook National University, Daegu, Korea.
3. Department of Dermatology, School of Medicine, Catholic University of Daegu, Korea.
4. Department of Dermatology, School of Medicine, Keimyung University, Daegu, Korea.
5. Department of Dermatology, College of Medicine, Yeungnam University, Daegu, Korea.
6. Department of Dermatology, College of Medicine, Dongguk University, Gyeongju, Korea.
7. Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.