1. Department of Pediatrics, Graduate School of Medicine, Chiba University, Chiba 263-8522, Japan.
2. Department of Pediatrics, Chiba Kaihin Municipal Hospital, Chiba 261-0012, Japan.
3. Department of Pediatrics, Shimoshizu National Hospital, Chiba 284-0003, Japan.
4. Satou Clinic, Arao 864-0041, Japan.
5. Department of Allergy and Rheumatology, Chiba Children's Hospital, Chiba 266-0007, Japan.
6. Abe Hiroki Children's Clinic, Chiba 264-0028, Japan.
7. Sunrise Children's Clinic, Chiba 273-0035, Japan.
8. Tsubaki Children's Clinic, Chiba 260-0001, Japan.
9. Mana Children's Clinic, Chiba 266-0032, Japan.
10. Katsuyama Clinic, Chiba 299-2117, Japan.
11. Nakayama Clinic, Chiba 275-0021, Japan.
12. Higashi Koiwa Wanpaku Clinic, Tokyo 133-0052, Japan.
13. Department of Pediatrics, National Hospital Organization Chiba Medical Center, Chiba 260-8606, Japan.
14. Chiba Rosai Hospital, Ichihara 290-0003, Japan.