Microcomedones
A comedo is a clogged hair follicle (pore) in the skin. This small plug is called a microcomedo. If sebum continues to build up behind the plug, it can enlarge and form a visible comedo.
Part of: Acne Lesions, Comedones
See also: Acne Skin Care
About Microcomedones
Found over most of the body, pilosebaceous units consist of a sebaceous gland connected to a canal, called a follicle, that contains a fine hair. These units are most numerous on the face, upper back, and chest. The sebaceous glands make an oily substance called sebum that normally empties onto the skin surface through the opening of the follicle, commonly called a pore. Cells called keratinocytes line the follicle.
The hair, sebum, and keratinocytes that fill the narrow follicle may produce a plug, which is an early sign of acne. The plug prevents sebum from reaching the surface of the skin through a pore. The mixture of oil and cells allows bacteria Propionibacterium acnes (P. acnes) that normally live on the skin to grow in the plugged follicles.
These bacteria produce chemicals and enzymes and attract white blood cells that cause inflammation. (Inflammation is a characteristic reaction of tissues to disease or injury and is marked by four signs: swelling, redness, heat, and pain.) When the wall of the plugged follicle breaks down, it spills everything into the nearby skin—sebum, shed skin cells, and bacteria—leading to lesions or pimples. NIH – National Institute of Arthritis and Musculoskeletal and Skin Diseases
