Thought I'd post my experience of what worked for me in terms of clearing up acne, as I've gleaned some useful advice from these forums in the past. I'm of Oriental/Chinese descent and while I don't know if this will be of any use for anyone else, I certainly think with acne having some genetic causation, my experiences might be relevant to those of the same/similar ethnicity.
Background - Severe, scarring acne especially on the cheeks since age 13; Tried multiple topical treatments without success. Gave up and gave in to what I thought were the inevitable 'volcanos' erupting on my face on a weekly/daily basis. Then finally at the age of 27, realised I was stupid to accept the consequences of this disfiguring disease so passively and researched everywhere for answers. Essentially, the 2 major steps which helped were:
1. Roaccutane - 4 months on high-dose of Roaccutane. Didn't work straight away, but gradually noticed some improvement. Main side effects were the usual dryness of face and lips. However, after the 4 month course and thinking that was my acne gone for good, I still had infrequent breakouts which left more scars and then stumbled on the next step which has helped me to avoid breakouts for a whole year now.
2. Total dairy avoidance - Sounds too simple to be true. But it worked for me - no more breakouts since I've omitted milk completely from my diet. I have accidentally consumed milk-containing products once or twice, which triggered small, non-scarring spots. There is apparently quite a well-established link between milk and acne, but no dermatologist anywhere will ever tell you about it. As I said before, acne certainly has a hereditary component to it and especially with people of East Asian descent, having not had milk in our diets for the last few centuries, to suddenly switch to a dairy-laden Western diet will almost certainly have some effect. For some, it's just mild bloating and flatulence, but for others I think acne is one consequence.
I've also switched to using the Eucerin Dermopurifyer range of products and use a very small dose of topical Retinoin for the residual scars. My complexion is by no means flawless, but it's certainly a great deal better than what it was a year and a half ago. Hope my experiences will be of some benefit to others with the same problem.