1. Division of Pulmonology, Allergy and Critical Care Medicine, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
2. Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
3. Department of Pulmonary, Allergy, and Critical Care Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
4. Department of Pulmonology, Allergy and Critical Care Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
5. Department of Allergy and Clinical Immunology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
6. Department of Internal Medicine, Ewha Woman's University College of Medicine, Seoul, Korea.
7. Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea.
8. Department of Internal Medicine, Veterans Health Service Medical Center, Seoul, Korea.
9. Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, College of Medicine, Seoul St Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
10. Division of Pulmonology, and Allergy, Department of Internal Medicine, Kyung Hee University Medical Center, Seoul, Korea.
11. Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea.
12. Department of Internal Medicine, Eulji General Hospital, Eulji University School of Medicine, Seoul, Korea.
13. Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea.
14. Department of Allergy and Clinical Immunology, Kangwon National University School of Medicine, Chuncheon, Korea.
15. Department of Allergy and Pulmonology, Chungnam National University Hospital, Daejeon, Korea.
16. Division of Allergy and Immunology, Department of Internal Medicine, Institute of Allergy, Yonsei University College of Medicine, Seoul, Korea.
17. Department of Internal Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
18. Division of Respiratory Medicine and Allergy, Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Korea.
19. Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
20. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
21. Department of Internal Medicine, Inje University College of Medicine, Ilsan, Korea.
22. Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
23. Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.