Teenage and Adult Acne
Types of Blackheads

Blackheads

Open comedones, which are called blackheads. The black color is the result of surface pigment (melanin) rather than dirt. Blackheads are small, dark spots about the size of a pinhead caused by discoloration of the surface of a small plug in the opening of a follicle/pore. Comedones are small non-inflammatory lesions, which may be flesh colored, white, or dark bumps that give skin a rough texture and appearance. The bumps are found at the opening of a sebaceous follicle/pore. Comedones form because plugs of sebum and old skin cells block the pores in your skin.

The cells lining the sebaceous duct proliferate excessively in acne and may block the sebaceous duct forming a comedone. These may be so small that they are not visible to the naked eye called microcomedones or quite large and deeper called nodules. Comedogenic refers to anything that tends to clog pores and produce comedones. Comedonal acne is a type of acne in which most lesions are comedones such as blackheads and whiteheads and with no other kinds of skin lesions. These are the non-inflamed blackheads and whiteheads that occur on the forehead and chin of those with acne, adult acne or rosacea. The singular is "comedo".