my husband has an inflammation in the crack of his butt almost by his back. only so often it will bother him and some times even bleeds. the pain is very severe. my 8 mth old looks like she will have the same thing. just wondering if you ever heard of this before.
Could be just dry skin that becomes irritated...does it especially hurt in the shower, like when water runs down his back? Try some vaseline just to keep the area moisturized.