1. Department of Allergy Beijing Shijitan Hospital Capital Medical University Beijing China
2. Department of Otolaryngology Head and Neck Surgery Beijing TongRen Hospital Beijing Key Laboratory of Nasal Diseases Beijing Institute of Otolaryngology Capital Medical University Beijing China
3. Jarud People's HospitalJarud Banner, Tongliao Inner Mongolia China
4. Erenhot Community Health Service Center Erenhot Inner Mongolia China
5. Xilingol Mongolian Hospital Xilinhot Inner Mongolia China
6. Xiwu People's Hospital Xiwu Banner Inner Mongolia China
7. Kailu People's Hospital Kailu County Tongliao Inner Mongolia China
8. Duolun People's Hospital Duolun Inner Mongolia China
9. TongliaoCity Hospital Tongliao Inner Mongolia China
10. Department of Otolaryngology Yong Loo Lin School of Medicine National University of Singapore Singapore Singapore
11. Department of Epidemiology and Statistics Institute of Basic Medical Sciences Chinese Academy of Medical Sciences School of Basic Medicine Peking Union Medical College Beijing China