Modern Medicine offers an online “dermatology counselor:” http://www.modernmedicine.com/dermcounselor. The site is fun and interesting. How helpful is it? That’s hard to say.
The Internet continues to offer us new resources. Some day, perhaps we’ll be able to take and send digital photos to someone who can give us good advice. But for now, my advice is that if you have a skin rash, see your doctor or find a dermatologist.