Same but different, my dog has acne, I have recently said goodbye to another dog.
Dog no1 with the acne developed a huge carbuncle (a group of boils) we think it was because he was a bit depressed losing his mate.
We treated it by putting a warm compress on it first thing in morning and last thing at night.
To make compress I used boiled water cooled down so I could put my finger in it for 30 seconds, I added Epsom salts to water, 1 tsp to half cup of water, using a clean lint free cloth, I immersed to cloth in the water, rung out excess water and held cloth to carbuncle for 10 minutes, I the used a cotton bud dipped in tea tree oil rubbed over area, then applied a breathable dressing. After 2 days boils burst open, I washed area with an anti bacterial soap then repeated compress and dressing routine. The boil becomes softer and a little more painful as it drains. By day 6 the boils were gone and his acne improved no end.
You can use bread soaked in warmed milk as well as a compress (old fashioned way)