I would suggest starting with a good internal medicine or family doctor. They know alot more than you think, can do a series of different tests and keep all the results in one place. If your med doctor is one of those, then you have a good start. Seeing a bunch of specialists without someone being the coordinator can get very confusing very fast. That being said, I think a dermatologist is your next speciality. Hair is a skin appendage so that's who takes care of hair problems.