1. Department of Pediatrics, Asan Medical Center Children's Hospital, Seoul, Korea.
2. Childhood Asthma Atopy Center, Asan Medical Center Children's Hospital, Seoul, Korea.
3. Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
4. Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
5. Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
6. Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea.
7. Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.