1. Department of Pediatrics, Childhood Asthma Atopy Center, Humidifier Disinfectant Health Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea;
2. Department of Convergence Medicine, Asan Institute for Life Sciences, and
3. Humidifier Disinfectant Health Center, Asan Medical Center, Seoul, Republic of Korea;
4. Department of Pediatrics, International St. Mary’s Hospital, Catholic Kwandong University College of Medicine, Incheon, Republic of Korea;
5. Department of Pediatrics, Chonnam National University Hospital, Chonnam National University Medical School, Gwangju, Republic of Korea;
6. Department of Pediatrics, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea;
7. Department of Pediatrics, Mediplex Sejong Hospital, Incheon, Republic of Korea;
8. Department of Pediatrics, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Republic of Korea; and
9. Department of Environmental Health, Korea National Open University, Seoul, Republic of Korea