1. Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.
2. Drug Safety Monitoring Center, Seoul National University Hospital, Seoul, Korea.
3. Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
5. Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea.
6. Department of Internal Medicine, School of Medicine, Kyungpook National University, Daegu, Korea.
7. Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
8. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
9. Department of Internal Medicine, College of Medicine, Ewha Womans University, Seoul, Korea.