How do you cure fungus on box turtle?

I have a baby Eastern Box Turtle and I think she has foot fungus on one of her foot and her head. Anyways, what causes foot fungus? How can you cure it? If it gets whiter is it getting better?How do you cure fungus on box turtle?
I would need a lot more information. What type of subtrate do you have it on? Was it wild caught? What diet do you have it on? How large of a water bowl does it have and is it in the tank 24 hrs a day? etc etc etcHow do you cure fungus on box turtle?
take it out of the box