1. Department of Public Health; Graduate School of Medicine; Chiba University; Chiba; Japan
2. Department of Pediatrics; Graduate School of Medicine; Chiba University; Chiba; Japan
3. Department of Pediatrics; Shimoshizu National Hospital; Yotsukaido; Japan
4. Department of Allergy and Rheumatology; Chiba Children's Hospital; Chiba; Japan
5. The First Department of Pediatrics; Toho University Omori Medical Center; Tokyo; Japan
6. Department of Otolaryngology; Head and Neck Surgery; Graduate School of Medicine; Chiba University; Chiba; Japan