Roseola infantum is a disease characterized by a fever, followed by a rash after the fever subsides. This disease is caused by an infection with human herpesvirus type 6 or type 7. Typically, it starts with a fever lasting three to five days, which can be moderately high. Generally, a rash appears after the fever subsides, primarily on the torso but it can also spread to the limbs. The rash usually fades within about two days and leaves no scars once it has disappeared.