I've been paleo since August 2008 and only just cleared up most of my acne in the past couple of months. I'm a 28 year old female and should be long done with acne but it's been a problem for me since I was about 15 (not severe but always there). I've never had weight problems (too skinny if anything), but I've experienced digestive problems since I was very young.
Something that recently changed about how I view paleo is that I've stopped thinking of it as a diet based on things I've STOPPED eating. When I thought of it like this, I was eating the typical grass fed hamburger meat with tons of veggies, lots of coconut products, no dairy, little fruit and lots of salmon and for some reason I was still getting acne. Eggs were phased in and out and I removed all nightshades for a while too. I tried adding fish oil and it actually got worse. I was also still getting bloated and having digestive problems on this. I still stuck to it because I'm just a huge Robb Wolf fan (who isn't..), it all made logical sense, and other than my acne and some persistent digestive problems, my body comp significantly improved and I still felt a ton better than before. The problem is the typical definition of paleo diet: DON'T eat grains, dairy, legumes...etc. Cutting these things out is a good start but there is so much more to this, and I don't believe supplements are the answer (I take vit D3 and magnesium - that's it).
What changed a few months back is I started focusing on getting more nutrients in my diet. You could say my diet was pretty nutrient dense before, but I knew it could be better. I started making paleo for me more focused on what I SHOULD eat. As much as it was an ephiphany for me to realize how much sense the paleo diet made, it was almost as much of a breakthrough for me to take this next step and start adding in some more "unusual" foods.
The first thing I did was I taught myself how to make bone broth out of grassfed beef bones (dirt cheap, by the way). It is incredibly soothing to the digestive system. Now I make a batch of that every week and scoop the broth-jello out of a container and drink it hot in a mug whenever I feel like it. I also started adding in sardines. I never liked them before but I started eating a more expensive brand packed in olive oil and they taste great. I read something about vitamin K2 and started added in organic butter (can't find grass fed stuff here in Canada). When I realized I could tolerate butter I took the next step and bought some Kefir. Surprisingly, I handled it just fine. And all the while, despite the fact that dairy is supposed to make acne worse, mine was improving. I've since been able to eat some small amounts of high fat organic cream cheese and aged white cheddar with no problems. I also added in raw saurkraut. A few more recent additions have been mussells, oysters, and beef liver ground up into my hamburger. I eat free run eggs with deep yellow yolks. I am no longer afraid of fruit, I'm not concerned that the sugar in fruit will cause flareups, because that just doesn't happen when that base inflammation isn't there. Don't get me wrong, I still eat the stuff I ate before on paleo, but the difference in adding in these foods has made an incredible difference. One thing I have noticed is that I cannot tolerate nuts at all. Nuts = almost immediate acne for me.
I know we are all n=1 scenarios coming from different experiences and some people seem to believe in a "detox" period for going paleo, some people can't handle dairy at all, some people can't handle carbs...etc. Maybe your diet deficiencies are different than mine, but I really do believe that if you are giving this a fair shot, then MISSING things in your diet can be as harmful as adding in all those harmful grains, sugar, etc. If you really are still struggling with this diet, please consider adding in some of these real foods. They've done wonders for me.