The rash is an acute febrile rash disease common in infants and young children, caused by human herpes virus type 6 infection, non-contagious, characterized by a rash after 3 to 5 days of high fever, with the characteristics of “fever and rash out”, the rash is a small dense red papules, head, face, neck and trunk, a day out of all! High fever is well relieved by oral antipyretics, and the general condition is good, with mild diarrhea! The main treatment is to reduce fever and symptomatic treatment!