J Liu1, J Hao1,2, Y Liu1, A Lallas3. 1. Department of Dermatology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China. 2. Department of Dermatology, Beijing ChuiYangLiu Hospital, Beijing, China. 3. First Department of Dermatology, Aristotle University, Thessaloniki, Greece.