Acne is a skin condition that occurs when your hair follicles become plugged with oil and dead skin cells.Acne most commonly appears in the teen age years on the face, neck, chest, back and shoulders. Acne can be distressing and annoyingly persistent.Acne lesions heal slowly, and when one begins to resolve, others seem to crop up. For some however acne continues into adulthood. Depending on its severity, acne can lead to scarring of the skin. The good news is that effective treatments are available — and the earlier treatment is started, the lower your risk of lasting physical and emotional damage.