1. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea.
2. Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, South Korea.
3. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
4. Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, South Korea.
5. Department of Dermatology, Seoul National University Bundang Hospital, Seongnam, South Korea.
6. Department of Internal Medicine, Korea University Medical Center Anam Hospital, Seoul, South Korea.