In most cases, children who already had roseola become immune to the virus and cannot contract it again, states Mayo Clinic. Most people create antibodies to the virus by the time they reach school age, so a second infection is highly unlikely.
Roseola is a mild illness caused by two viruses in the herpes virus family. Children between the ages of 6 months and 2 years old are most likely to acquire the infection, but it is possible for adults who never had the virus to contract a mild version of the illness.
Roseola symptoms include a sudden high fever that lasts up to 8 days, followed by a pink rash on the neck, arms and torso. Over-the-counter acetaminophen or ibuprofen and sponge baths can help manage any discomfort until the virus resolves on its own, notes WebMD. Consult a physician if symptoms worsen or the rash lasts longer than 1 week.