Acne is a common skin disease that affects 85-100% of the population. Although it often appears during puberty, it may persist during the third decade of life and even later. It is characterized by a variety of lesions consisting of non-inflammatory lesions known as comedones, and inflammatory lesions such as papules, pustules, nodules and cysts. It commonly occurs on the face, chest, and back. Although not as noticeable as facial acne, truncal acne may also affect a person's self esteem and body image and reduce one's participation in sports because of the need to undress in a shared locker room. Most acne studies focus on facial acne and ignore treatment outcomes in the chest and back.