1 Department of General Pediatrics, Division of Infectious Disease, Department of Pediatrics, Tokyo Metropolitan Children's Medical Center, Fuchu, Tokyo, Japan.
2 Department of General Pediatrics, Tokyo Metropolitan Children's Medical Center, Fuchu, Tokyo, Japan; Department of Epidemiology, UCLA Fielding School of Public Health, Los Angeles, California.
3 Department of General Pediatrics, Tokyo Metropolitan Children's Medical Center, Fuchu, Tokyo, Japan.
4 Department of Dermatology, Tokyo Metropolitan Children's Medical Center, Fuchu, Tokyo, Japan.
5 Department of Radiology, Tokyo Metropolitan Children's Medical Center, Fuchu, Tokyo, Japan.