1. Department of Pediatrics, Seoul Medical Center, Seoul, Korea.
2. Department of Dermatology, Seoul Medical Center, Seoul, Korea.
3. Department of Pediatrics, Inje University School of Medicine, Seoul, Korea.
4. Department of Pediatrics, Asan Medical Center, Seoul, Korea.
5. Department of Dermatology, Chung-Ang University College of Medicine, Seoul, Korea.
6. Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea.