An infection that is due to human herpesvirus (HHV) types 6 or 7; it is characterized by 3-5 days of high fever followed by the acute onset of a rosy, pink, non-pruritic, macular rash that is predominantly on the neck and trunk. The disease is exanthema subitum (MONDO_0000337, a Monarch Disease Ontology identifier). Also known as: exanthem subitum, roseola, roseola Infantum, sixth disease.