My Child Who Is Five Recent Came Home With A

My child who is five recent came home with a fever for one day next day she was. However she started these fever blister looking things around her mouth she has gotten them before but usually not this bad. She has gotten them in the past and doctors have called it the herpes virus and or shingles or cold sores she got it real bad this last we have had her cleared up for about a week and now it seems to be coming back. What do we need to do where do I need to go how do I fix this for my child they are extremely painful for her and very upsetting? Please help.