How to get rid of dark dead skin between thighs and the ass hole.

Can't say.: You can't get an answer from your description. This could be anything from a melanoma to an infection to normal skin with a color you don't care for. If you want the problem assessed, your primary care doctor or a dermatologist will actually have to look at it to find out what it is. Without knowing for sure what it is, no one can tell you what will help.