Okay, not mine, my husbands. It looks like athlete's foot and he used an over the counter spray and cream. That didn't work so he went to his regular doctor twice and has used the creams they prescribed but it is still there.
It is more on the top of his foot, between the big toe and second toe, about the size of a quarter. It is like a dry, flaky patch and it itches.
We went through what could have caused it, the cleaning product used in our shower hasn't changed, nothing is different, but it has been over a month now and it hasn't changed.