There are a number of steps you can take to help get rid of back acne and stop breakouts. A lot of times, back acne will come about because you are sleeping too hot and sleeping on your back (or your just sweating too much during the day). You need to stop the sweat and back oils from building up on your skin and developing into backne, so try the following suggestions to stop back acne.
Keep in mind, your diet may also be one of the biggest contributors of your backacne, especially "skim milk" (or any milk or dairy products). So be mindful of you diet and make changes to it, and see if your backacne begins clearing up after a month or two.
1) Change your shirts often, especially after sweating or working out. Also make sure you put on a clean shirt before bed and a clean shirt in the morning.
2) DO NOT Sleep too hot so you are sweating. Wearing less to bed is your best bet. DO NOT wear socks to bed. If you're a guy, try sleeping without a shirt and only wearing boxers/ briefs so you can avoid overheating and sweating.
3) Bedroom temperature is best at a slightly cool room temp of around 64°
4) Try to avoid sleeping on your back (easier said, than done).
5) Take a shower when you wake up in the morning and take a shower before going to bed so you don't sleep with grease and sweat on your back. If you workout, make sure you take a shower after any exercise to get rid of any sweat build up.
6) Use a back Loofah to exfoliate any dead skin from your back in the shower. However, don't overwash/ scrub or it could make things worse.
7) DO NOT use regular soap to scrub your back, instead use soap like PanOxyl Bar and/or a Body Wash like Neutrogena Body Clear Wash, which contains Salicylic acid acne treatment. Keep in mind, that the Salicylic acid can discolor non-white bathtowels.
8) After you dry off from your shower, spray your back with Neutrogena Body Clear Body Spray. This works very well at getting rid of back acne. It's best to use twice a day after your shower. Within a month you should definitely start seeing good results. The body spray will dry out your skin, so once you're back starts clearing up, you may want to cut back on how often you spray your back.
9) Change your bed sheets at least once a week, so you have clean sheets and not sweaty/dirty sheets. (I heard Kelly Rippa say she changes her bed sheets every night, just take a look at her skin, I doubt you'll see any back acne).
10) Drink less "skim milk" (or any milk). A 2012 study in Italy, found a connection specifically between skim milk and acne. This is likely because of "a higher amount of bioavailable hormones in skim milk, since they cannot be absorbed in surrounding fat," which can then overstimulate the group of glands that produce our skin's natural oily secretions, according to the American Academy of Dermatology.
11) Eat less eggs and less dairy products overall. If you're eating a eggs (hard-boiled, scrambled, etc) everyday, then try cutting eggs out of your diet for a while.
12) Caffeine may also be the cause of acne (coffee, soft drinks, etc.)
13) You may have a hard water problem in your home's water supply (hard water contains high metal and minerals), which may affect your back acne or cause other skin issues. If you have lime and rust build up around your faucets, shower head, and in tiolets, you probably have hard water. You can test for hard water, with Hard Water Test Strips. If you can afford it, install a Soft Water system to your home's water supply to get rid of Calcium and Magnesium in your water. To get rid of chlorine, install a Shower Water Filter.
Overall, your diet may be the biggest factor in the cause of acne (back acne) that is persistent, so be sure to inspect your diet for possible food allergies or links to certain foods that you eat regularly, which may be the leading cause of your acne.
NOTE: If these suggestions don't start working for you within a month or two, you may need to see a dermotologist for your acne problems. The doctor might prescribe an antibiotic called Minocyline to treat your back acne.