1. Dermatology Hospital, Southern Medical University, Guangzhou, Guangdong, China
2. Guangdong Provincial Center for STD Control, Guangzhou, Guangdong, China
3. Anhui Medical University, Hefei, Anhui, China
4. Guangzhou Panyu Chronic Disease Prevention and Treatment Station, Guangzhou, China
5. Shantou Dermatology Hospital, Shantou, Guangzhou, China
6. Jiangmen Dermatology Hospital, Jiangmen, Guangzhou, China
7. Zhongshan Second People's Hospital, Zhongshan, Guangzhou, China
8. Shenzhen Center for Chronic Diseases Control, Shenzhen, Guangzhou, China
9. Shaoguan Center for Chronic Diseases Control, Shaoguan, Guangzhou, China
10. Maoming Center for Chronic Diseases Control, Maoming, Guangdong, China
11. Zhuhai Center for Chronic Diseases Control, Zhuhai, China
12. Binhai Bay Central Hospital of Dongguan City, Dongguan, China
13. Guangzhou Institute of Dermatology, Guangzhou, China