What Causes Peeling Skin On The Buttocks?

The skin on my inner buttox cheeks, beginning at my anus and extending outward, started peeling heavily. At first i assumed it was just a rash or irritation, but after using several different broad spectrum antifungual ointments and creams, and having the peeling reoccur after just a few days...i think its something more serious. The peeling creates a blistered ring on the edge of the peeling, which is darker than the rest of the area, and painfully. The area that has peeled becomes smooth a different texture from the skin in that area. The peeling is so severe that the upper crease (not sure what the proper term is) of my anus becomes raw, like a cut. plz help