I m having a recurring ringworm problem. I ve had it three times, with each occurrence a few years apart. It presents as a single round rash-type lesion with no other discomfort - no itch, pain, burn, ooze - and it doesn t spread, just takes many months to go away. The most recent outbreak was this past April. My doctor prescribed Ketaconazole, which I ve been using for about 5 months, I but still have the rash. I m thinking to switch to Lotrimin for Ringworm (clotrimazole). Do you have an opinion on the most effective treatment for this condition?