Hi, Am 36 years old and have always had an oily scalp with dandruff ever since my teens. Also hair on my head has always been thick & very fast growing.. Suffered from acne on face & had a dermatologist subscribe a course of Roacutane for 6-12 months when I was 21 years old as part of the treatment. Anyway last year I did’nt wash my hair for a bit (2-3months) and noticed an excess build up of thick dandruff near the crown area this finally prompted me to shampoo regularly - once a week using Head & Shoulders shampoo with a conditioner – but at the start of this year a friend noticed a noticeable thinning around the crown with much of the scalp clearly visible, almost the exact same area where the excessive build of dandruff was when I hadn’t washed my oily scalp for a 2-3 month period. Now my question is: Have I (that excess dandruff build up) done some permanent damage to hair follicles in that crown area? Will that 3-4 inch thin area near the crown ever recover to its former glory? FYI – rest of the hair is reasonable thick and grows fast & long as normal, but there is a visible thin patch near the crown surrounded by longer healthy hair. Cheers Baz