Acne problems vary in degree from person to person. But no matter how simple or how complicated they are, they always start from blackheads. Blackheads are comedones that are open. They have slightly larger openings than normal follicles. These openings are filled with plugs of bacteria, dead skin cells, and sebum. The oil or sebum plugs have oxidized melanin that happens at the surface, that is why blackheads are slightly darker or â€œblackishâ€â€”thus, the name.