I realize this is a very old message, but just in case new readers are googling this problem, this sounds very much like lichen sclerosus to me. I had it for YEARS, consulted both GPs and dermatologists, and was prescribed yeast infection treatments that did no good whatsoever. It wasn't until I saw a new and very highly rated gynecologist that I got the right diagnosis. A course of steroid cream and I was cured.