slapped cheek syndrome; fifth disease; erythema infectiosum
Colloquial Japanese term for erythema infectiosum, a common childhood viral illness causing a bright red rash on the cheeks. The medical term is 伝染性紅斑.
See also: 伝染性紅斑
My child caught slapped cheek syndrome and their cheeks turned bright red.
Slapped cheek syndrome is formally called erythema infectiosum.
Literally 'apple disease', from the characteristic red cheeks resembling an apple.