I have a rash on my inner elbow area of my right arm (in the crease). I have had it for almost 3 weeks now. It had gotten slightly bigger since I first noticed it. It's about the size of a quarter.. Maybe a bit bigger. It is not perfectly round. Sometimes I cannot even tell it's there unless I look at it at a certain angle where I can see very tiny raised dots. It gets more noticeable after I shower. Also, it does not itch at all. I have no other symptoms.. Fever, cold or anything like that. I do have problems with acne since adolecense and my skin can be pretty oily sometimes. I am 25 years old. What in the world could this rash be?