Suggest Treatment For Rashes On Both Sides Of The Torso

I have a rash that just broke out in both sides of my torso. I thought at first it was a bug bite but once I finally got up to look in the mirror I realized it's more than a bug bite. I have a stuffy nose and a slight bout of diarrea. I did sit in a jacuzzi last night... Don't know if that had anything to do with it?