Corresponding author
Soo-Jong Hong, MD, PhD.
Department of Pediatrics, Childhood Asthma Atopy Center, Humidifier
Disinfectant Health Center, Asan Medical Center, University of Ulsan
College of Medicine
Current address: Department of Pediatrics, Asan Medical Center, 88
Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea
sjhong@amc.seoul.kr ; Tel.: +82-2-3010-3379