<prompt> Fever stops and rash begins is diagnostic ofFifth diseaseRoseola infantumMeaslesToxic shock syndrome  <response>: Roseola infantum Sixth disease or exanthem septumIt is caused by human herpesvirus-6 HSV-6Similar illness is caused by Parvovirus B-19 and Echovirus.Age group involved is 6 mt to 3 yr.Incubation period 5 to 15 days.Clinical manifestationsAbrupt onset with high-grade fever, mild pharyngitis and Coryza.The temperature comes down rapidly in 3 to 4 days when a macular or maculopapular rash appears, starting from the trunk and sometimes extending to the extremities and face.The rash lasts for 24 hours, and disappear in 1-2 days without pigmentation or desquamation.There is occipital and post-auricular lymphadenopathy. 