1. Department of Internal Medicine, College of Medicine, Ewha Womans University, Seoul, Korea.
2. Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea.
3. Department of Allergy and Respiratory Medicine, Konkuk University Medical Center, Seoul, Korea.
4. Department of Pulmonary, Allergy and Critical Care Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
5. Department of Internal Medicine, Hallym University College of Medicine, Anyang, Korea.
6. Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
7. Division of Allergy and Clinical Immunology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
8. Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, Korea.
9. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
10. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
11. Department of Internal Medicine, Soonchunhyang University College of Medicine, Bucheon, Korea.
12. Department of Internal Medicine, Chonnam National University Medical School & Hospital, Gwangju, Korea.
13. Department of Internal Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea.
14. Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea.