Monday, March 11, 2019

Case of the Week 535

This week's case is by our awesome dermatopathology fellow and former chief resident, Kabeer Shah. The following was seen in a scraping of a papule from a patient with rosacea. Identification?

Check out the way this little guy moves!

14 comments:

Bernardino Rocha said...

These are follicle mites, Demodex sp. (probably D. folliculorum). They are elongated and vermiform, with 3 body divisions: gnathosoma (anterior end); podosoma (4 pairs of appendages); opisthosoma (posterior rounded end)

Dr. Fernando FariƱas said...

Demodex folliculorum

Anonymous said...

Demodex brevis

-HLCM fan

Anonymous said...

Like my former colleague, I think it's about Demodex brevis.
Luis.

Anonymous said...

Demodex brevis

Idzi P. said...

Demodex sp. (Follicle mite).

Luis said...

Demodex sp

Anonymous said...

For sure a classic case of Demodex sp. I would leave the species identification to a true entomologist.
Florida Fan

Kosta Y. Mumcuoglu said...

Quite sure is a Demodex folliculorum. D. brevis has a V like shape in his posterior part of the body. Living in the sebaceous glands D. brevis can be seen much less often than D. folliculorum which lives in the hair follicles.

BISHAL said...

Demodex

Blaine A. Mathison said...

So many people think they live immaculate lives
but among their hair follicles another creature thrives
you can shower and scrub to your heart's content
but all that effort won't make a dent
because the mite Demodex folliculorum continues to survive

Old One said...

I agree with the other bloggers. The critter is Demodex sp. And I will wait with Florida Fan for a more professional identification.

Demodex has long been considered a very common commensal of humans. We would find high percentages of our students providing a cozy living space for these tiny mites. Giving credence to the thought that it is probably living in just about everyone.

Recently it has been suggested that higher populations of this mite might have a role in developing Rosacea in human patients. One hypothesis is when elevated populations of Demodex die they release bacteria loads which initiate an inflammatory response. It is thought the bacteris is entirely responsible for the reaction not the mite. This might be why there are cases of Rosacea which are refractile to traditional treatment but do respond when Demodedic treatment is added.

Demodex from a veterinary prospective.
There art 65 species of Demodex . All the common domestic animals have their own species. They are host specific capable of only transient cross infectivity.

We normally diagnose with skin scrapings, but have seen them in fecal flotations (along with their rhombus shaped eggs). The Greek derivation of the genus: Dermos = fat, dex= woodworm. I would be less impressed with the translation if it weren’t for the fact that we often see another mite that mimics Demodex and are common in fecals. These mites cause leaf galls in trees.

I have also seen Demodex in modified Knott’s preparations. A lucky blood draw, I guess.

William Sears said...

demodex

Unknown said...

Well said.