Adult acne is the worst! They kept telling me once I grew up and became a full-fledged adult that I wouldn't have to worry about acne.
AH-HA~ this is the reason......I never became a full fledged adult!

My Rutherford had a bad case of kitty acne. I just washed the area with alcohol and used neosporin (at the recommendation of a vet tech friend). It took a while, but it went away completely.