Yes, creams do not really help. The white patches are due to the melanin being damaged,so the skin turns white. There is no real cure as such, as it is not really classed as a disease.It can have many causes,but diet is important to stop it spreading further.
Junk food is a no-no! And watch your fat intake. The body needs fat,contrary to popular belief, especially the skin; the largest organ in your body!
This "ailment" has been known to clear of itself.
However, as there is usually no pain with Leucoderma, you may just have to put up with it. If you say it is only on your foot, I wouldn't worry too much; but not very pleasant if you swim or sunbathe! Can be quite unsightly. Albinos suffer from the same lack of melanin.