When I accidentally let my scalp get too oily, it causes an SD flare and my scalp (and even my face and ear canal a little bit) gets super itchy and the dandruff appears. When I wash my hair then, I’ve got at least 3-4 times as much hair in the drain than normally even though I comb thoroughly before washing. This will continue for a week or two until my scalp has settled down with a few medicated (H&S) washes. I can also tell that my circumference has decreased significantly (used to be easily iii, now middle of the road ii) since I first started experiencing SD years ago. I have heard and read similar stories from so many with SD, so it’s anecdotal, but I can’t point to you any studies or whatever.

Wanted to add something else that might be important. I developed SD about 10 years ago when I was working out daily. I didn’t want to invest the time to wash my long hair daily, so I tried to stretch washes. That is when the itching first started, on the day after not washing a sweaty scalp. I didn’t think much of it and it was a nuisance, but I didn’t change my washing habit of every 2-3 days even with daily workouts. So slowly over time I started to lose circumference Just wanted to mention this in case anybody is in a similar situation. Don’t ignore the itch; it’s trying to tell you something is wrong.

There is a whole thread on here about SD, so that would be a good place to check out also.

There are also threads about SD on skin issue specific forums, for example I used to read a lot on a rosacea forum. Some folks there had success with a natural honey protocol. It’s elaborate and messy, but your hair might be short enough as to where you might be willing to tackle it.

Hope this helps.