I'm 99.9% sure this is Roxy's issue.
I noticed one big one, a few weeks ago. Thought she got scratched by something (or someone) and it formed a scab. It was gone within 2-3 days.
Her "spot" is on top of the refrigerator, so she is pretty much at eye level for me. I noticed a bunch more a few days ago. Started Googling....
Possible changes that could be the cause... she is fed raw chicken for every meal. (Poultry has always been a constant. The only change is the raw.) It is mixed with wet food. She isn't fond of raw only. I don't feed fish, grains, or loads of carbs. Water added is bottled water.
Dr. Mercola doesn't mention stress, but last week would have been a highly stressful week for her. We had company...and lots of it. EDIT: That wouldn't explain the one a few weeks ago.
Food and water bowls are metal. The food bowls are washed after every meal. The water bowl is washed once a day. None of the cats drink water... hardly ever. Her food bowl is pretty wide (5 inches), but it is also about 1/2 inch deep. It has never been a problem before, but...
I did try to wipe her chin after she ate, even though I didn't see any food on it. Not sure how much I actually got wiped. She isn't a cat that likes to be held or touched, except on her terms.
Two days ago, I changed her feeding dish to one of our plates...just in case.
I wonder if it is possible her chin is getting "germ-y" from the raw food/dish combo?
It does look MUCH better today.
It's important that any underlying conditions like mange, a yeast infection or allergies are identified and resolved. I find that removing unnecessary grains and carbohydrates from the diet, as well as giving cats a break from both seafood and poultry as protein sources, can make a huge difference in preventing a recurrence of feline acne.
If a kitty has intermittent recurring acne, you can proactively swab her chin with a cotton ball dipped in witch hazel or hydrogen peroxide once a week to prevent or control flare-ups.
If your cat's food or water bowl is plastic, you might also consider switching to a shallow stainless steel or non-toxic ceramic to eliminate a potential plastic or dye allergy as the cause of the acne. I also recommend you evaluate your kitty's diet, her vaccine load, her environmental chemical load, and the water and air quality in your home.
http://healthypets.mercola.com/sites/healthypets/archive/2013/12/09/feline-acne.aspx