skin disease, characterized by areas of skin w/ seborrhea (scaly red skin), comedones (blackheads and whiteheads), papules (pinheads), pustules (pimples), Nodules (large papules) and possibly scarring. Acne involves mostly skin with the densest population of sebaceous follicles; these areas include the face, the upper part of the chest, and the back. Severe acne is inflammatory, but acne can also obvious in noninflammatory forms. The lesions are caused by changes in pilosebaceous units, skin structures consisting of a hair follicle and its associated sebaceous gland, changes that need androgen stimulation.
Acne occurs most commonly during adolescence, and often continues into adulthood. In adolescence, acne is commonly caused by an increase in testosterone, w/c people of both genders accrue during puberty. For most people, acne diminishes over time and tends to disappear or at the very least decrease after one gives one's early twenties. There is, however, no way to predict how long it will take to disappear entirely, and some people will carry this condition well into their thirties, forties, and beyond.