1. Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Korea.
3. Department of Internal Medicine, Armed Forces Capital Hospital, Seongnam, Korea.
4. Department of Internal Medicine, Seoul Metropolitan Government: Seoul National University Boramae Medical Center, Seoul, Korea.
5. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
6. Department of Pediatrics, Yonsei University Wonju College of Medicine, Wonju, Korea.
7. Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.
8. Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea.
9. Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, Korea.
10. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
11. Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea.
12. Division of Allergy, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
13. Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.