1. Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea
2. Department of Occupational and Environmental Medicine, Inha University School of Medicine, Incheon, Republic of Korea
3. Department of Occupational and Environmental Medicine, Inha University Hospital, Incheon, Republic of Korea
4. Department of Internal Medicine, Dong-A University College of Medicine, Busan, Republic of Korea
5. Department of Allergy, Asthma and Clinical Immunology, Chonnam National University Hospital, Gwangju, Republic of Korea
6. Department of Allergy and Clinical Immunology, Ajou University Hospital, Suwon, Republic of Korea
7. Department of Internal Medicine, Ewha Womans University College of Medicine, Seoul, Republic of Korea
8. Department of Internal Medicine, SMG-SNU Boramae Medical Center, Seoul, Republic of Korea
9. Division of Respiratory Medicine and Allergy, Department of Internal Medicine, Jeonbuk National University Medical School, Jeonju, Republic of Korea
10. Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Republic of Korea
11. Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
12. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea