For several years, starting in about October of each year, both of my thumbs have the skin crack and split wide open. This takes place at the tips in a line extended from the sides of my thumbnails. This is painful as the splits are deep and I work with my hands alot (farming). I've tried alot of different hand creams (daily or more). This year I also have splits on a couple of fingers and one of my heels has a couple. I've had this since I was about 22 or so. I live in Manitoba. Any help (ie: diet, supplements, meds, etc) would be appreciated.