Like facial acne, body acne is so common among adults and teens. It usually shows up on the upper chest, back, and buttocks, and is caused by several factors like stress and hormones. Of the various factors that trigger the formation and development of body acne, perspiration as well as tight fitting clothing is considered by many as two of the most common culprits of body acne, which then somehow explains why most of the many physically active women are bothered by body acne.