I would definitely get the second opinion. Can't hurt. If the docs think the rash is ringworm, did they give you anything to treat it? If so, is it working?
Hang in there and go see the other rheumatologist. Start keeping a journal of your symptoms...when they started, how long they last, etc. This information will be helpful in terms of communicating to the new rheumy exactly what is going on. I have found that the docs respond better when I am organized.
Good luck and keep us posted.