Kitty acne is caused from bacteria. What kind of bowls do you put his food and water in?? If it's plastic, get rid of it and use stainless steel. Make sure you wash them out once a week.

My cats had kitty acne. I used Hexadene shampoo (found at the vet's office) on it. I'd use a exfoliating sponge with the shampoo on it and scrubbed their chins once a day. Then I'd put 2% Benzoil Peroxide on it. Eventually it went away.

Sounds like your cats acne is a little more serious than my cat's were.

Good luck.