Suggest Treatment For Cuts On Butt Crack

Since I had a baby 21 months ago...I started getting cuts on my butt crack...some times I get them in the crotch area also. I use zinc oxide but it doesn't seem to work. It is now getting itchy.... I asked my OB about it and she gave me a steroid cream that I had a really bad reaction to. I don't understand why this keeps happening and how to make it go away. I try to be careful when I wipe....