ACK!!! I have a rash...details.

[Mears]

Ok, I just got back from an exam and I took off my sweater and I noticed I had a pretty big rash on and around my elbow. It wasn't there this morning and I have no idea when it first showed up. It is basically a dense area of scaly red dots. It was pretty hot and crammed in the exam room so maybe it is a heat rash? Does anyone have any ideas? I'm freaking out over here.