How To Treat Mono?

My daughter who is 14 may have mono, were awaiting for the blood results. She was prescribed augementin and now has an all over itchy rash. She also has an allergy to penicillin (don't ask). She started taking prednisone yesterday and taking benadryl, but is itching like crazy. Is there something else I can do at home for her without having to take her to the er? We are applying cold compresses, taking warm baths and applying anti itch cream along with aloe vera.