that is ridiculous!! this day and age at least the source and cause of an itchign sensation should be able to be establlished...If mine is not got to the bottom of i will not be happy infact i will be certifiable after over a year and half already of intense unexplained itching and now the appearance of so many white areas in various areas of my young 34 year old body...it is totally unacceptable. I have had experience of one dermatologist for this which i have to say left a lot to be desired and my mother in lawa had experience of another and from what we can see, dermatologists dont seem to have a clue of very much and they also dont seem to care less once they get their big fat fee. It all seems a hit and miss and guessing game to the dermatologists that are around today. They are a waste of time!
I'm afraid I can't comment much from this distance. Like most dermatologists, I have many patients with chronic itch. Controlling this is hard--cortisone creams, topical anesthetic lotions, oral antihistamines--all of these are used (I'm sure you've tried some as well.) You doctor will need to keep trying different methods. However, you may well not be able to abolish the problem altogether, just control it. If necessary, seeing another doctor just to get a fresh perspective may be of use. But there's usually not a magic bullet for this kind of thing.
By the way, I don't know what a "pin stroke" is. If you mean a neurological stroke, you might ask your neurologist whether the kind of itch you have is common afterward, and whether special neurological medications might be of use.
Best.
Dr. Rockoff