1. Department of Pediatrics, Hallym University Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Korea.
2. Department of Pediatrics, Ajou University Hospital, Ajou University School of Medicine, Suwon, Korea.
3. Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
4. Department of Pediatrics, Childhood Asthma Atopy Center, Environmental Health Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
5. Department of Pediatrics, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
6. Department of Pediatrics, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
7. Department of Pediatrics, Inha University Hospital, Inha University College of Medicine, Incheon, Korea.
8. Department of Pediatrics, Seoul Medical Center, Seoul, Korea.
9. Department of Pediatrics, Inje University Ilsan Paik Hospital, Inje University College of Medicine, Seoul, Korea.
10. Department of Pediatrics, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
11. Department of Pediatrics, National Health Insurance Corporation Ilsan Hospital, Seoul, Korea.
12. Department of Pediatrics, Soonchunhyang University Seoul Hospital, Seoul, Korea.