comedo

Meanings

1. A clogged hair follicle in the skin, formed when keratin combines with oil to block the follicle.

Etymology

From Latin comedō (“glutton”). Applied to blackheads on account of the popular belief that they were parasitic worms that consumed the host’s nutrients, especially in children, thereby causing weight loss and illness. Compare Danish hudorm (“comedo”, literally “skin-worm”). More information In Johann Heinrich Zedler's universal lexicon, comedo is one of four Latin translations for the entry Mitesser, Zehrwürmer and Dürrmaden, literally "along-eaters", "draining worms" "dry-maggots", which are described as "aschenfarbige oder schwärzlichte Würmlein … sie pflegen in der Haut der jungen Kinder nicht anders als kleine schwarze Härlein zu stecken: und sind eine ordentliche Ursache der Schwindung und Abnehmen der Kinder; Die Kinder schreyen und weinen unter steten Wachen, und denn sagen die Weiber, das Kind sey entweder beschrien, oder habe die Mitesser. Diese Würme kann man aus der Haut locken …", translated: "ash-colored or blackish little worms which are found in the skin of young children with the appearance of tiny black hairs. They are a major cause of children's weight loss; the children cry and scream constantly and won't fall asleep. To this the women say that the child is either cursed or has comedones. These worms can be lured out of the skin." Likewise, in Johann Theodor Jablonski's lexicon from 1721, Latin comedones is found as a translation for Mitesser along vermiculi cutanei, which translates to "skin-worms". Curiously though, this entry provides a sensible explanation: "Sie werden vermuthlich aus einem fette und rohen saffte, so sich von dem geblüt scheidet, und durch die verstopften schweißlöcher nicht ausdämpffen kan, erzeuget", translated: "They are probably produced from fat and a raw humor that separates from the blood and cannot evaporate through the blocked sweat pores." Likewise, the Bartholomaei Castelli Lexicon Medicum Graeco-Latinum from 1713 says the following about comedones: "Comedones etiam appellantur a quibusdam medicis vermiculi illi in dorso infantum & puerorum per poros cutaneos prominentes cum subsequente contabescentia, qui alias dicuntur crinones …", translated: "Comedones are also called, by some physicians, those little worms that can be found in the backs of infants and children, that come forth through the pores of the skin, with a following weight loss. They are elsewhere called crinones.." Likewise, Heinrich Mylich explains in his inaugural dissertation from 1827: "Comedones ita dicti sunt, quod, priusquam Vogel natu