Comedones is the scientific name for clogged pores, also known as blackheads and whiteheads hair follicles that have become blocked by a mixture of bacteria, sebum, and shed skin cells. They can appear on both the face and body, appearing as white or black spots on the skin’s surface. Comedones differ from pimples in that they are neither tender nor inflamed, which is why blackheads and whiteheads are classified as non-inflammatory acne.
A comedo initially forms as a white, "closed" lesion, but if the pore opening widens enough for its contents to be exposed to oxygen, oxidation occurs, turning it a dark brown or black color. This is how an open, black comedo commonly known as a blackhead is formed. The dark coloration is not due to dirt in the pores, as was once believed. Unfortunately, many old misconceptions persist, so it is important to clarify that blackheads are not caused by poor hygiene. They develop internally, and the condition is often genetically determined.
When an excess of dead skin cells, sebum, and bacteria accumulate within a pore, a blockage eventually forms in the follicle opening. For a long time, it was believed that comedones resulted from hardened sebum clogging the pore, but this is not the case. The real culprit is an overproduction of skin cells inside the pore, leading to congestion. This phenomenon is known as hyperkeratinization, which is where genetic predisposition comes into play. Individuals with a genetic tendency for hyperkeratinization are more prone to developing comedones.
As these substances build up inside the hair follicle, the follicle walls contract, but the sebum produced in the narrowed pore does not become completely trapped. Instead, it is slowly pushed toward the surface through a narrow channel, which remains open due to a protein-dissolving enzyme released by bacteria. Since this enzyme breaks down the keratin plug at the same rate as new skin cells are produced along the follicle walls, a state of balance is maintained, preventing the comedo from growing indefinitely.
White comedones are only considered "closed" in the sense that they remain protected beneath the skin’s surface. There is always a small pore opening, even if it is too narrow to release the blockage. In an open blackhead, the pressure inside the follicle has increased to the point where the pore opening gives way and expands. Essentially, the pore reaches its limit and releases the comedo. All blackheads eventually reach this stage, but it can take time for the contents to be expelled naturally. This is why it may be tempting to squeeze comedones, but this is rarely a good idea. Squeezing can cause the follicle walls to rupture, spreading the contents under the skin and potentially triggering deeper inflammation that may lead to scarring.
If you are impatient, it is better to have a professional skin therapist perform a manual pore extraction. With the right skincare, you can also accelerate the process and prevent new comedones from forming.
