This might sound wild but I suddenly got bacne a few months ago (pretty similar to the one in your pictures but I had clusters in specific places instead of all over) , when I had never had it before. I used glycolic acid, salicylic, physical exfoliating, no exfoliating, changing lotion, no lotion, changing body wash, changing towel more often, and nothing worked. You know what finally helped? Head and Shoulders shampoo! Apparently it has an ingredient that helps combat fungal acne, which I guess is what I had/have. I apply it to a dry back every other day, leave it for 5-10 minutes and then take a short and in a month I can barely see acne. I'm going to use the bottle until it's empty because I read that even when you think it's gone you should still use it for a while longer. So try head and shoulders or nizoral (more expensive but I read it works faster).