Acne is the term for plugged pores (blackheads and whiteheads), pimples, and even deeper lumps (cycsts or nodules) that occur on the face, neck, chest, back, shoulders and even the upper arms. Acne commonly occurs in people between their teenage years and their 20s. However, it is not restricted to this age. Older adults and children can also have acne. You can do a lot to treat acne using products available at a drugstore or cosmetic counter, that do not require a prescription.