Roseola reinfection? Can a child come down with roseola twice?

Not exactly. Roseola is most commonly caused by a virus called hhv-6 (human herpes virus-6, and you can only get this illness once. There are, however several look alike illnesses caused by different virus groups including hhv-7, enteroviruses, adenoviruses, and parainfluenza viruses that can closely resemble roseola and would fool most anyone.