How do you make the diagnosis of DUPA (Diffuse Unpatterned Alopecia)?

The only way to determine DUPA is with a video microscope showing the details of the donor area. I always insist that the area I look at is cut short (a couple of mm long) so that I can count the miniaturized hairs. A count in excess of 20% of miniaturized hairs reflects DUPA as I defined it in my published article. Yes, finasteride sometimes works to reverse it (less that 50% of the time).