I was pretty spotty as a teenager. When I got discouraged with yet another failed attempt to clear up my face, my dermatologist would try to comfort me saying “but your back and chest are always clear”. His heart was in the right place, if not his science.
Acne on the back ( aka bacne) and acne on the chest is more common in men and especially during adolesence. It appears where hair follicles ( which have oil glands) are either more numerous or more active. Its also harder to see what is going on below the neck and in the back, and thus harder to clear.
The Best Bacne Treatment