I never post anything on these types of boards, but I suffered from perioral dermatitis for 6 months and it was miserable. I tried everything- yogurt, probiotics, apple cider vinegar (I don't understand how that works for anyone, it dried my skin out so bad) I tried colloidal silver, calendula cream, tea tree oil. You name it, I tried it. What finally helped me was getting my thyroid checked. It was low!! I started 6 days ago on levothyroxine and it has pretty much entirely cleared up. I'm scared as I type this that its going to come back, but with each day that goes by it seems to get better and better. I just hope this helps someone else, because maybe it is just something as simple as a thyroid problem.