You absolutely do not have FD. That is my biggest concern with this forum, the misdiagnosis. People come in here with superficial folliculitis and think that they have FD, when there skin condition is no more harmful than minor acne. The fact that you say your hair is extremally greasy is of interest. I notice that many with very oily skin have true scalp acne. Probably a similar process to true acne. A hair would prevent the follicle from being clogged in the Acne sense, however I postulate that a shed telogen hair would allow the follicle to be clogged in the same way as a follicle on the face in the case of highly active sebaceous activity. These are the types that are most likely to retain lasting remission from accutane. In cases where folks have dry skin but scalp folliculitis, I believe there is an abnormality in the degrading of the root sheath. Two different situations with similar clinical picture. I believe accutane may pose the cure for you, or at least grant lasting remission. Good luck.