Suggest Treatment For A Large Skin Rash On The Shin

I have an appointment with a dermatologist tomorrow. I had a rash on my right shin which I definitely contracted from the gym. It showed up about 2 days after. I was doing sit ups on a decline bench, and the rash showed up where the shin pad was rubbing against my leg. It seemed to be under control with neosporin and went away after about a week. The problem is that it obviously never went away completely. Around one month later, It is much larger now and I now have a rash on both elbows as well as my shin. At first I was thinking that it s a staph infection, but now I m concerned that it s scabies. Do you have any input in the likelihood of it being either of those? Thank you.