My DD had a similar problem a couple of years ago. The dr recommended using a broad spectrum (eg canesten) cream, used in the following way: before they go to bed, spread a thick layer over the affected area. Then cover it with a non-absorbent covering (we used gladwrap as it was on dd's leg, so easy enough to wrap and tape). This technique makes the skin soak up more of the active ingredient, so it works more quickly. We did it every night for a few nights followed by every second night until it was all clear. I would try this for a week in preference to oral antifungal a as they are nasty. You will know within a week if it is working or not, and if not you can try the tablets instead.