I think the cause of my own personal acne has been overexfoliation all along... my derm has prescribed me Finacea (15% azelaic acid). I started using it 2 x a week and it was looking good! Next time I saw him, he told me that since my skin was tolerating it to try it every night! At first I thought it was just purging, but break outs increased... haven't used it since Wednesday and haven't had new breakouts...
Coincidence, or can overexfoliation really CAUSE acne?
I have gone through the same thing before...
I was using Peter Thomas Roth's Glycolic hydrating gel. It's good stuff...I was using it every third day for a couple weeks, then I stepped up to every other day...a month into in, my skin was perfect, clear and glowing. Then, after a couple weeks of perfectly clear skin, I started breaking out. I thought (since the directions said to increase until you were using it twice a day) maybe it would help if I used it every night. Things only gradually got worse. Yes...over-exfoliation waspartof the problem. The other one is that I keep smearing all this crap all over my face. The PTR gel only contains oneknowncomedogenic ingredient...but with frequent use, I've found it doesn't take much. Some of these ingredients may only rate a "1", but they were only tested for 72 hours, not a month.
I think with the PTR gel, it was a combo effect...yes, I was over-exfoliated--my skin had become more sensitive by the end, not less. I also think the ingredients build-up in my pores, if used too frequently.
I decided to buy a Clarisonic and try to do a physical method of exfoliation, rather than glopping on more goo. I've been using it "as needed" and going by feel, rather than a strict schedule.