Why does Propecia (Finasteride) make acne so much worse when conventional science says it should do the opposite?

Whenever I try taking propecia, I get horrible acne after less than a week of taking it and so now I have given up on Propecia. It seems to go against the "science" out there that has associated high DHT levels with more sebum and acne. Logic leads me to conclude that Testosterone must be the real cause of increased sebum and acne, not DHT, as propecia increases free T levels in the blood by inhibiting conversion into DHT. ANy insight on this from someone who knows the science?