excellent point Jade...forgot the most obvious cause of feline acne....absolutely use preferably glass or metal dishes...NOT plastic!!!!
Just to add to Opus' excellent advice, if you're feeding from a PLASTIC dish, change to ceramic...or anything other than plastic which can harbor bacteria causing breakouts.
hi this is so very common anymore....and almost ALL the time is due to food allergies, mainly grains in their food.(cheap additives). is your kitty fed dry food? these are the worst for allergies. the best possible advice I can give you is to change to a CANNED food with NO grains...kitty's don't like this very much b/c of course like us they love carbs...so its like going from french fries to broccoli, so you can't do it over night. do a 50/50 mix and gradually have him totally OFF dry carb loaded food.
I will send you this site just to do some additional reading on food allergies and itchies..
however I DO NOT recommend the DRY PRESCRIPTION foods they advertise on the page.....they are dry for one, and loaded with grains as well as very expensive.
I DO NOT also recommend the cortisone treatment mentioned...this is only a band aide and steroids lead to many other health issues for kitty...post again if we can help.
btw. it would also help to try a different litter....and stop all chemicals in your home, b/c itchies can also be a contact or inhaled allergy...but food is the most common.
http://www.marvistavet.com/html/body_food_allergies.html