An open comedo is usually known as a blackhead it’s a type of acne vulgaris, it is a blackish or yellowish bump or plug on the skin. It causes due to excess oils that have accumulated in the sebaceous gland’s duct.

All acne is not the same. The acne can be divided into red bumps and blackheads/whiteheads. This division is important because each type is treated differently. Blackheads and whiteheads, known as comedones, can be more numerous on the face and shoulders than red bumps filled with pus.


Blackheads, is usually known as open comedones, are follicles that have a wider than normal opening. They are filled with plugs of sebum and sloughed-off cells and have undergone a chemical reaction resulting in the oxidation of melanin. This gives the material in the follicle the typical black color.