A friend has been going through this, and he decided to see both an endo and a dermo, so you might want to consider those options so they can run some tests and try to get to the bottom of it.
He found that stress and genetics were contributing to the problem, but he was also deficient in several vitamins and nutrients, so he is now dealing with it on several levels, which, last time we talked, seem to be helping. You also might want to check out Nioxin hair products which is what he is now using.
