Comedo

"Blackhead" redirects here. For other uses, see Blackhead (disambiguation).
Comedo
Other namesPlural: comedones[1]
Illustration comparing a normal skin pore with a whitehead and a blackhead
SpecialtyDermatology

A comedo is a clogged hair follicle (pore) in the skin.[2] Keratin (skin debris) combines with oil to block the follicle.[3] A comedo can be open (blackhead) or closed by skin (whitehead) and occur with or without acne.[3] The word comedo comes from Latin comedere 'to eat up' and was historically used to describe parasitic worms; in modern medical terminology, it is used to suggest the worm-like appearance of the expressed material.[1]

The chronic inflammatory condition that usually includes comedones, inflamed papules, and pustules (pimples) is called acne.[3][4] Infection causes inflammation and the development of pus.[2] Whether a skin condition classifies as acne depends on the number of comedones and infection.[4] Comedones should not be confused with sebaceous filaments.

Comedo-type ductal carcinoma in situ (DCIS) is not related to the skin conditions discussed here. DCIS is a noninvasive form of breast cancer, but comedo-type DCIS may be more aggressive, so may be more likely to become invasive.[5]

  1. ^ a b "Comedo". Oxford Dictionary. Oxford University Press. Archived from the original on December 21, 2013. Retrieved 16 June 2013.
  2. ^ a b Informed Health Online. "Acne". Fact sheet. Institute for Quality and Efficiency in Health Care (IQWiG). Retrieved 9 June 2013.
  3. ^ a b c Cite error: The named reference LancetW was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference CEAcne was invoked but never defined (see the help page).
  5. ^ National Cancer Institute (2002). "Breast cancer treatment". Physician Desk Query. National Cancer Institute. PMID 26389187. Retrieved 13 June 2013.