Sorry your son is so sick. Yes, I've heard of this type of virus and we've had it. Those rashes/hives move around in a way it's almost eerie. Just keep up the benedryl for a day or so. No hot baths or showers as it increases or activates them. Fluids, rest, dress loosely and keep cool. Good luck. Btw, age is not a barrier. When my son got this one, I got it too. Wash your hands and stay clear as possible. Hard when you're trying to cure those viruses with tlc.