A book that I have says tinea versicolor can be treated with creams containing either "azole antifungal cream" or "selenium sulfide." I just bought a tube of generic antifungal cream today for less than $2. It is called "clotrimazole," which sounds like it might work for what you have, according to that book. (I picked up ringworm from the kittens, they just couldn't keep it to themselves!) Also, the selsun blue with selenium is the selenium sulfide. So if you are patient, it sounds like you can treat it with OTC medications. They just take a lot more time than a pill, usually. Good luck.