Skin inflammatory (nontumor)
Infestations
Demodex


Topic Completed: 1 June 2011

Revised: 23 April 2019

Copyright: 2002-2019, PathologyOutlines.com, Inc.

PubMed Search: Demodex [title] skin
Page views in 2018: 2,199
Page views in 2019 to date: 1,328
Cite this page: Hamodat M. Demodex. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/skinnontumordemodex.html. Accessed June 16th, 2019.
Definition / general
  • Mites are commonly present in inflamed follicles but are usually nonpathogenic (Wikipedia: Demodex [Accessed 14 February 2019])
  • Common in dogs
  • Demodex folliculorum is also known as the follicle mite
  • Typically considered harmless
Epidemiology
  • Common in basal cell carcinomas removed from the eyelids
Sites
Clinical features
Case reports
Microscopic (histologic) description
  • Follicular dilatation, the presence of dense homogenous eosinophilic material surrounding the mites, folliculitis and perifollicular chronic inflammation
  • Often is a granulomatous reaction to extrafollicular Demodex, usually in granulomatous or pustular rosacea
  • May see telangiectasia of superficial vessels, perifollicular granuloma and mild perivascular chronic inflammation
Microscopic (histologic) images

Contributed by Bobbi Pritt, M.D.

Toe nail of elderly
Florida woman -
KOH Calcofluor staining
of Demodex folliculorum

Adult Demodex
folliculorum
has
8 legs, typical of
arachnids, not insects

Demodex mite found in rosacea papule

Videos

Demodex mite

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