I am in southeast asia and have contracted an unknown growing skin rash. The locals say it is very common in tropical areas but everyone gives me different ideas for treating it. It grew from a small pink ring with a white center to a big red ring with pimples throughout the red area, still with a distinct white center. Is this ringworm? I don't think so, because it doesn't itch at all, just hurts, and there is only one outbreak on my upper arm. Help! It's getting bigger, and I don't know what it is or how to treat it!