I remembered a case I dealt with, where the client suffered from severe cystic acne. I referred her to a naturopath and after a thorough consultation they concluded that she had build up an intollerance to animal protein.
Apparently, my client and her family had red meat based meals every single night, roasts, steaks and the like. The naturopath suggested her body was so overwhelmed with so much animal protein it was trying to eliminate the toxins via her skin, hence the acne.
They did the experiment and she eliminated animal protein from her diet and the results were immediate and astonishing. Her skin cleared up within weeks. Whenever she tried a sausage or steak her acne returned. It was mainly from red meat, bird or fish flesh wasn't so bad. She had to get right off red and white meat to keep her skin clear.
This made me think of my ex who had severe acne on his back for many years since he was a teenager. On the advice of a naturopath ( after many failed attempts of doctors and dermatologists) we gradually eliminated food groups from his diet, then slowly re-introduced foods until his acne flared up again. His problem we discovered were eggs. Interestingly, another animal protein. He could not eat anything with eggs in it without getting serious acne on his back, neck and jaw line.
So think about what foods trigger your acne. Animal protein is a big culprit, wheat, citrus fruit, dairy and sugar are worth looking into.