I Have Had A Rash On My Lower Back And

I have had a rash on my lower back and upper buttocks for about a year and I didn't think much of it until my wife said something the other day how it looks like i have scarred my back. The itch continues and I have tried lotrimin ultra and antibacterial creams as well as home remedy creams. Nothing stops the burning intense itch and it gets worse when I sweat. Please help. Thank you.