1. Department of Pulmonary, Allergy and Critical Care Medicine, College of Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University, Seoul, Korea.
2. Department of Allergy and Clinical Immunology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
3. Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Chung-Ang University Gwangmyeong Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine, School of Medicine, Kyungpook National University, Daegu, Korea.
5. Department of Allergy and Clinical Immunology, Chonnam National University Hospital, Chonnam National University Medical School, Gwangju, Korea.
6. Department of Internal Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea.
7. Department of Allergy and Clinical Immunology, Kyungpook National University Chilgok Hospital, School of Medicine, Kyungpook National University, Daegu, Korea.
8. Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
9. Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea.
10. Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea.
11. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
12. Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
13. Department of Internal Medicine, Pusan National University College of Medicine, Busan, Korea.
14. Department of Internal Medicine, Jeju National University Hospital, Jeju National University School of Medicine, Jeju, Korea.
15. Departments of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.