Whitehead
A familiar term for what is medically called a closed comedo. A comedo, the primary sign of acne, consists of a dilated (widened) hair follicle filled with keratin squamae (skin debris), bacteria, and sebum (oil). A whitehead is a comedo that has an obstructed opening to the skin. A closed comedo may rupture and cause a low-grade skin inflammatory reaction in the area. By contrast, an open comedo has a wide opening to the skin and is capped with a blackened mass of skin debris. It is commonly known as a blackhead. Acne occurs when sebaceous glands of the skin begin to secrete oil during puberty. These glands are stimulated by male hormones that are produced in the adrenal glands of both boys and girls. The oil lubricates and protects the skin. Under certain circumstances, cells that are close to the openings of the sebaceous glands block the openings. This causes a buildup of oil underneath the skin. Bacteria, which live in everyone's skin but generally mind their own business, feast on this oil, multiply, and cause the surrounding tissues to become inflamed. If the inflammation is right near the surface, a pustule is formed; if it is deeper, a papule (pimple); deeper still and it becomes a cyst. If the oil breaks though to the surface, the result is a whitehead. If the oil becomes oxidized (that is, acted on by oxygen in the air), the oil changes from white to black, and the result is a blackhead. This is how the two types of comedones develop.
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Walter, English surgeon, 1840–1913. See W. deformity, W. operation.

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white·head -.hed n MILIUM

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white·head (hwītґhed) 1. milium. 2. closed comedo.

Medical dictionary. 2011.

Look at other dictionaries:

  • Whitehead — can refer to:People* Alan Whitehead, a British Member of Parliament * Alfred North Whitehead (1861–1947), a British philosopher and mathematician * Axle Whitehead (b. 1980), 2003 Australian Idol contestant * Cortlandt Whitehead (1842–), bishop *… …   Wikipedia

  • Whitehead — ist der Familienname folgender Personen: Alfred North Whitehead (1861–1947), britischer Philosoph und Logiker Annie Whitehead (* 1955), britische Jazzposaunistin Chad Whitehead (* 1987), australischer Badmintonspieler Dean Whitehead (* 1982),… …   Deutsch Wikipedia

  • Whitehead —   [ waɪthed],    1) Alfred North, britischer Mathematiker und Philosoph, * Ramsgate 15. 2. 1861, ✝ Cambridge (Massachusetts) 30. 12. 1947; lehrte 1885 1910 Mathematik am Trinity College, Cambridge, ab 1914 als Professor für angewandte Mathematik… …   Universal-Lexikon

  • Whitehead — torpedo White head tor*pe do, or Whitehead White head , n. A form of self propelling torpedo. [Webster 1913 Suppl.] …   The Collaborative International Dictionary of English

  • Whitehead — White head , n. (Zo[ o]l.) (a) The blue winged snow goose. (b) The surf scoter. [1913 Webster] …   The Collaborative International Dictionary of English

  • Whitehead — Whitehead, Alfred North …   Philosophy dictionary

  • Whitehead — Whitehead, Alfred North …   Enciclopedia Universal

  • Whitehead — (Alfred North) (1861 1947) mathématicien et philosophe américain d origine anglaise; l un des princ. théoriciens de la logique mathématique …   Encyclopédie Universelle

  • whitehead — ► NOUN informal ▪ a pale or white topped pustule on the skin …   English terms dictionary

  • Whitehead — [hwīt′hed΄, wīt′hed΄] Alfred North 1861 1947; Eng. mathematician & philosopher, in the U.S. after 1924 …   English World dictionary

  • whitehead — [hwīt′hed΄, wīt′hed΄] n. nontechnical term for MILIUM …   English World dictionary

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