1 Department of Dermatology, Beijing Tian Tan Hospital, Capital Medical University, Beijing 100070, China.
2 Department of Dermatology, Chinese Academy of Medical Sciences, Peking Union Medical College, Peking Union Medical College Hospital, Beijing 100730, China.
3 Department of Education, Chinese Academy of Medical Sciences, Peking Union Medical College, Peking Union Medical College Hospital, Beijing 100005, China.
4 Department of Dermatology, University of Pennsylvania, Philadelphia, PA, USA.