1 Department of Pediatrics, Chonnam National University Hospital, Chonnam National University Medical School, Gwangju, Korea.
2 Department of Pediatrics, Childhood Asthma Atopy Center, Environmental Health Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
3 Department of Occupational and Environmental Medicine, Inha University School of Medicine, Incheon, Korea.
4 Department of Chemical Biotechnology, Seokyeong University, Seoul, Korea.
5 Department of Pediatrics, Inje University Sanggye Paik Hospital, Inje University Medical School, Seoul, Korea.
6 Department of Pediatrics, Mediplex Sejong Hospital, Incheon, Korea.
7 Department of Pediatrics, International St Mary's Hospital, Catholic Kwandong University, Incheon, Korea.
8 Department of Pediatrics, Pusan National University Yangsan Hospital, Yangsan, Korea.
9 Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Environmental Health Center for Atopic Disease, Samsung Medical Center, Seoul, Korea.
10 Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea.
11 Department of Pediatrics, CHA Medical Center, CHA University College of Medicine, Seoul, Korea.
12 Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.
13 Department of Pediatrics, Childhood Asthma Atopy Center, Environmental Health Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. Electronic address: sjhong@amc.seoul.kr.