Comedone

A comedone is a clogged pore that forms when a mix of sebum (skin oil) and dead skin cells becomes trapped inside a hair follicle. Comedones are the basic, non-inflamed lesions of acne, and they represent the starting point from which inflamed pimples can later develop if bacteria and inflammation get involved.

They come in two main forms. An open comedone, commonly called a blackhead, has a widened pore opening where the trapped material meets the air and darkens through oxidation, not because it is dirty. A closed comedone, or whitehead, forms under a thin layer of skin that keeps the contents sealed, appearing as a small, skin-colored or pale bump.

Comedones are influenced by how much oil the skin produces and how readily dead cells shed from the follicle lining. Ingredients described as comedogenic are those with a tendency to contribute to this clogging, though whether a given product causes comedones varies from person to person and depends on the whole formula, not one ingredient alone. Approaches often discussed for comedone-prone skin include gentle, consistent cleansing and ingredients that support cell turnover, such as salicylic acid and retinoids. Squeezing or picking is generally discouraged, and persistent or severe breakouts are worth reviewing with a dermatologist.