What Causes Dry, Scaly, Peeling Skin In Anus?

Dry, scaley, like a sore that heals with the dead skin on top that can be pealed. That is how my butt crack feels. What is this? It happen often, I m a woman, I wear thongs. Sometimes my thong will cut me, so I ll put a&d ointment on it and it ll heal and the dead skin will fall away and my crack will be normal. Now months later my butt crack has suddenly turned into the dry, burn felt skin. If I rub it, it feels kind of like it can be peeled, I can feel where it ends; but it doesn t peel. It s not even my whole butt crack, it s a little lower in the buttcrack, but stops just as the anus begins to form.