blackhead

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blackhead

 [blak´hed″]
a plug of keratin and sebum within the dilated orifice of a hair follicle. The dark color is caused not by dirt but by the discoloring effect of air on the sebum in the clogged pore. Infection may cause it to develop into a pustule or boil. See also acne vulgaris. Called also open comedo.

blackhead

/black·head/ (blak´hed) open comedo.

blackhead

(blăk′hĕd′)
n.
1. A skin lesion consisting of a hair follicle that is occluded with sebum and keratin, appearing black at the surface.
2. An infectious disease of turkeys and some wildfowl that is caused by a protozoan (Histomonas meleagridis) and results in lesions of the intestine and liver. Also called enterohepatitis, histomoniasis, infectious enterohepatitis.

blackhead

See comedo.

blackhead

A blocked sebaceous gland which is open to air, where the secretions oxidise, turning black.

blackhead

Open comedo A blocked sebaceous gland which is open to air, where the secretions oxidize, turning black. Cf Whitehead.

his·to·mo·ni·a·sis

(his'tō-mŏ-nī'ă-sis)
A disease chiefly affecting turkeys, caused by Histomonas meleagridis and characterized by ulcerative and necrotic lesions of the liver and cecum, acute onset, and a high mortality rate. It is transmitted inside the eggs of the nematode Heterakis gallinae, which is primarily responsible for maintaining and spreading the infection.
Synonym(s): blackhead (2) .

o·pen com·e·do

(ō'pĕn kom'ĕ-dō)
A comedo with a wide opening on the skin surface capped with a melanin-containing blackened mass of epithelial debris.
Synonym(s): blackhead (1) .

blackhead

An accumulation of fatty sebaceous material in a sebaceous gland or hair follicle, with oxidation of the outer layer, causing a colour change from white to dark brown or black. Blackheads, or comedones, occur in the skin disorder ACNE.

Blackhead

A plug of fatty cells capped with a blackened mass.
Mentioned in: Rosacea

Patient discussion about blackhead

Q. I have this blackhead on my cheek area for about a year..,How do I remove it?

A. This type of blackhead you are describing sounds like comedonal (non-inflammatory) acne, as opposed to acne that is inflammatory or severe inflammatory (which usually will not remain for a year on the skin). There are many basic local treatments which can be found at pharmacies over-the-counter. Whether it is gel or cream (which are rubbed into the pores over the affected region), bar soaps or washes - it is important to keep the skin clean of bacteria, that may worsen blackheads.

More discussions about blackhead
References in periodicals archive ?
All the affected individuals shared extensive comedones and pitted scars on the face, neck, and trunk, and reticulate pigmentation in the flexures areas.
The lesions first appeared on the back of her neck as 2–5 mm comedones and small inflammatory papules, which subsequently developed into pitted scars.
Both agents significantly reduced the number of inflammatory lesions and comedones (SOR: B).
Isotretinoin also reduces cell shedding and the stickiness of cells in the follicles, which helps prevent the development of comedones.
Alpha-hydroxy acids decrease the keratinocyte cohesion at the lower level of the stratum corneum, causing increased desquamation and possibly dislodging comedones and preventing their formation (Taffe, 1997).
Acne vulgaris is a chronic inflammatory disease of pilosebaceous units characterized by comedones, papules and pustules and less frequently by nodules, cysts and scars.
Cosmetics, and some moisturisers, too, can cause acne by blocking the pores with a greasy layer that encourages the proliferation of bacteria, providing the ideal conditions for comedones, or blackheads, to develop (a comedo being the basic acne lesion).
Closed comedones are raised flesh-colored follicular papules with non-dilated follicular openings.
On examination multiple grouped comedo-like black keratin filled pits and comedones were present in both the axillae and single comedones were noted in front of both the ears.
In seeking to explain this effect, Melnik and colleagues (2) studied epidermal lipid composition in early, noninflamed comedones from patients using isotretinoin.
Nevus comedonicus (NC), first reported by Kofmann in 1895, is a rare hamartoma of pilosebaceous unit resulting in numerous keratin-filled comedones, arranged in linear nevoid pattern.