One option not mentioned yet is the herb Usnea. I get it from HerbPharm or you can search for it and find it through online web sales.
My son gets ringworm once in a while. I have him take two dropperfulls twice a day. It is a powerful Antibiotic and antifungal.
Another note, my other son was taking it because he was sick with cold. He had some warts on the top of his hand and afterwards we realized that the warts had disappeared. Never to return.