What Causes Open Red Sore On Butt-crack?

I have an open red soreup my butt crack. I have gone to several specialists to no avail. One specialist said it looked like pililon idol 2 day post op. the nextbtime i saw him it had cleared up so he didn't come in the room to even see me just his intern. It is getting wose and after I went to the next 3 dr I have been told that I have to learn to live with it. That is no longer an option as it hurts to sit and wakes me up in the night because it hurt. I am using a cortizone cream it helped for a while but no longer has much effect.