Ringworm remedies?

I think I have it on my knuckles.  I would have self-diagnosed a long time ago... but just didn't think I could pick it up in Tokyo, so thought they were bug bites or some allergic reaction. 

Selsun Blue dandruff shampoo is the best thing I know of, but I can't find it here.

Any other suggestions?

I have suffered from Tinea (ringworm) for about 25 years. You can easily treat it with any athletes foot cream or thrush cream. It's all a yeast based fungus.
Because mine keeps returning I've been taking tablets once a year. I get it really bad on my back.