I'm not Mark, but I just wanted to mention that going primal actually cured my severe, cystic acne and RADICALLY increased nail growth. I should say that I eat a primal diet HEAVY in animal foods with almost no plants at all, and it wasn't until I started cutting out the green stuff (fruits in particular) that my acne began to disappear RAPIDLY. I know of other people who've had the same experience after going semi-carnivorous. I actually decided to give it a try because another guy in my area had cured his severe acne this way. Going super low-glycemic seems to be key for some of us.
I eat salmon every day and so never take fish oil.
Hope this helps.