Acne is thought to be largely genetic [1], which could explain why no one in that study had it.
Anecdotally, I had cystic acne as a teen and was cured after a single cycle of Accutane. It never returned, even though I kept eating the same diet - which included a lot of dairy and a lot of fast food.
Anecdotally, I had cystic acne as a teen and was cured after a single cycle of Accutane. It never returned, even though I kept eating the same diet - which included a lot of dairy and a lot of fast food.
[1] http://onlinelibrary.wiley.com/doi/10.1111/bjd.12149/abstrac...