1. Division of Pulmonology and Allergy, Department of Internal Medicine, KyungHee University Medical Center, Seoul, Korea.
2. Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.
3. Division of Pulmonology, Allergy and Critical Care Medicine, Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea.
4. Division of Pulmonary, Allergy, and Critical Care Medicine, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea.
5. Division of Pulmonology and Allergy, Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea.
6. Division of Allergy and Immunology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
7. Department of Pediatrics and Respiratory Disease Center, Chungbuk National University Hospital, Cheongju, Korea.
8. Department of Pediatrics, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea.
9. Department of Internal Medicine, Inje University Ilsan Paik Hospital, Goyang, Korea.
10. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.