1. Department of Allergy and Clinical Immunology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea.
3. Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Gangneung Asan Hospital, Gangneung, Korea.
4. Department of Allergy, Pulmonary and Critical Care Medicine, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul, Korea.
5. Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
6. Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
7. Department of Internal Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea.
8. Department of Internal Medicine, College of Medicine, Ewha Womans University, Seoul, Korea.
9. Department of Respiratory Medicine, Allergy and Clinical Immunology, Nagoya City University Graduate School of Medical Sciences, Aichi, Japan.
10. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
11. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.