Comedo

Oil production in the sebaceous glands increases during puberty, causing comedones and acne to be common in adolescents. Acne is also found premenstrually and in women with polycystic ovarian syndrome. Make-up and skin products that are oil-free and water-based may be less likely to cause acne. People of Latino and recent African descent may experience more inflammation in comedones, more comedonal acne, and earlier onset of inflammation. ==Pathophysiology==

and the alar of the nose Comedones are associated with the pilosebaceous unit, which includes a hair follicle and sebaceous gland. These units are mostly on the face, neck, upper chest, shoulders, and back. This small plug is called a microcomedo. If sebum continues to build up behind the plug, it can enlarge and form a visible comedo. They are closed comedones and are more frequent on the face than neck. Solar comedones (sometimes called senile comedones) are related to many years of exposure to the sun, usually on the cheeks, not to acne-related pathophysiology. ==Management==

Using non-oily cleansers and mild soap may not cause as much irritation to the skin as regular soap. Blackheads can be removed across an area with commercially available pore-cleansing strips (which can still damage the skin by leaving the pores wide open and ripping excess skin) or the more aggressive cyanoacrylate method used by dermatologists. Squeezing blackheads and whiteheads can remove them, but can also damage the skin. Others remove the dead layers of the skin and may help clear blocked pores. but dermabrasion and laser therapy have also been known to cause scarring. Retinoids should only be applied at night, since a) light degrades them, and b) the skin repair cycle peaks at night. Sunscreen should also be used during the day, as the skin becomes more sensitive to UV. ==Rare conditions==

Favre–Racouchot syndrome occurs in sun-damaged skin and includes open and closed comedones. Nevus comedonicus, or comedo nevus, is a benign hamartoma (birthmark) of the pilosebaceous unit around the oil-producing gland in the skin. It has widened open hair follicles with dark keratin plugs that resemble comedones, but they are not actually comedones. Dowling–Degos disease is a genetic pigment disorder that includes comedo-like lesions and scars. Familial dyskeratotic comedones are a rare autosomal-dominant genetic condition, with keratotic (tough) papules and comedo-like lesions. ==References==