I'm currently 16 years old. I never really noticed it. But today when i looked in the mirror, i had back acne covering the majority of my back. Its a blotchy reddish brown all over. I knew I had back acne, but not as bad. They aren't large pimples, and its embarrassing. I want to go swimming but I don't want to show my back. I sweat a lot during the summer but that never caused problems before. Most of the time i'm wearing 2 layers of clothing. an undershirt, and then a collard one. Could it be caused by that? What can I do to help it? And would wearing loose clothing or not wearing a shirt at home more often help it? Please help, thank you