Acne appears in various shapes, sizes, and colors. Unlike the red, patchy form of acne that causes redness and inflammation, blackheads appear in the form of black dots that exist on oily areas of the face. Also known as open comedos, blackheads are particularly common on the nose, forehead, and chin. They can contain skin debris, bacteria and sebum. The appearance and frequency of blackhead production can typically be reduced with acne treatment cleansers and solutions.