[lil fu fu girl]

Could be super dry skin or you might have picked up Athletes foot fungus. Either way, I would try to moisturize first. Use a cocoa butter lotion on your feet at night. Really soak it in and then put on socks. Try this for about a week. If it does not help or your feet start itching, then it probably is Athletes foot. Then you might want to pick up some Tinactin. I have been a runner for decades and I always seem to get it, so that is what I use and it seems to help.
Good luck.