Kelly, I'm sorry to hear that now 5 of your furkids have kitty acne. When I first found out that Sunny had acne, I was also feeding my boys out of ceramic dishes. I then switched to stainless steel ones and Sunny's acne cleared up for a while.
Now I've learned to live with the fact that he'll always have an acne problem so I try to clean his chin every night or every other night with a hot compress and hibiclens. I also wash all of their stainless steel meal dishes twice a day and their drinking dishes once a day with hot water and antibacterial soap. I also run them in the dishwasher once a week.
I've never heard of acne spreading from one cat to the other but it does seem that white chinned cats get it the most often. It's probably because we can see the acne on them better than on non white chinned cats. Hopefully Sky won't get this because he'd be difficult for me to clean. Good luck and please keep us updated.