1. Division of Pulmonology and Allergy, Department of Internal Medicine, Gachon University Gil Medical Center, Gachon University College of Medicine, Incheon, Korea.
2. Department of Internal Medicine, Gachon University Gil Medical Center, Gachon University College of Medicine, Incheon, Korea.
3. Division of Respiratory Diseases and Allergy, Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Korea.
4. Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
5. Department of Allergy and Clinical Immunology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.