Ever since i got off bactrim, an oral medication, i've had this rash on my stomach and back that burns and stings whenever i sweat or just get hot. On my chest it looks like i get heat rashes now, and i used to never get them, and it still stings. The rash on my back and stomach looks kinda like normal skin with little tiny bumps, but it only looks a little different than my own skin. I can notice it, but for someone else, they have to look more closely. Does this have to do with anything from bactrim? or is something else wrong with me?