I Have A Sore Rash In The Creases Around My

I have a sore rash in the creases around my nose and corners of my mouth. The only thing that takes the rash away is a steroid cream. I don't know why I get it. I have had it approx 6 months. I would like to know what it is and how to get rid of it. I have to put memetosome? On everyday or it comes back, I don't like having to do that. Do you have any suggestions? Thank you