What Is The Treatment For Rashes In The Neck?

I have a rash that is on my neck it looks like a burn. I do not know if it is a rash or a reaction to Epiduo Gel that I have been using to clear up my acne. It is only on my neck and it itches and as a result of me scratchimg it, it turns into a burn that eventually scales off and then a day or so later the cycle begins again just in a different spot on my neck of course.