1 Department of Dermatovenereology, West China Hospital, Sichuan University, No.37, Guo Xue Xiang, Wuhou District, Chengdu, 610041, Sichuan, China.
2 Department of Dermatoverenology, Chengdu Second People's Hospital, Chengdu, China.
3 Department of Dermatology and Venereology, Province Hospital, Birendranagar, Surkhet, Karnali, Nepal.
4 Department of Dermatovenereology, West China Hospital, Sichuan University, No.37, Guo Xue Xiang, Wuhou District, Chengdu, 610041, Sichuan, China. ranyuping@vip.sina.com.