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#45: Demodex Mites

Litinsects #45: Demodex Mites

Month of Mites, Part1

Let’s start the mites off right! Today’s post is about DEMODEX mites, also known as (drum roll please) face mites/eyelash mites! And if you believe that ignorance is bliss then I suggest you stop reading now... just kidding, you totally want to know this, I swear.

© Palopoli et al.

Demodex are a group of mites that live in the hair follicles of mammals. There are two species of Demodex that live on humans and, in fact, cannot survive anywhere else! The first, Demodex folliculorum, measures around 0.3 mm and lives inside hair follicles. The other, Demodex brevis, is around 0.1-0.2 mm and lives in sebaceous glands inside hair follicles (these are the glands that produce your skin oil, known as sebum). Both species feed on dead skin cells and oils inside your pores.

Now when I say “your”, I mean literally YOURS... (probably). It used to be thought that they were not so prevalent but more recent studies have found the prevalence to be at almost 100% in some human populations! As you can imagine, more recent advancements of techniques for testing for mite DNA (because where there’s mite DNA, there are mites!) turns out a much higher prevalence than traditional methods of “let’s look at some samples under a microscope and see if we find any mites”.

  • Believe it or not, both these mite species can be considered COMMENSALISTS. Commensalism is a type of symbiosis (aka, a close interaction between two or more species) that benefits one party and is neither beneficial nor harmful to the other. In other words, Demodex have it pretty good living on your face, whereas you (maybe up until you heard about them) probably couldn’t have cared less...
  • However, when present in very high densities, these mites can cause DEMODICOSIS (red, itchy, or scaly skin) or worsen pre-existing skin conditions such as rosacea, dermatitis, and acne. So some sources do refer to Demodex as parasites...
  • These mites are transmitted through close contact of infested skin. So pretty much any time two people’s faces touch, they could be swapping mites
  • Both Demodex species prefer the “oilier” parts of the body, hence they are usually found on the face, but they also survive in other areas. They are long and thin, adapted to live in tight pores
  • Individuals position themselves head downward inside the follicle. There can be up to 6 mites living inside a pore at a time! And the dead mites? I hate to break it to you, but they just decompose on your face...
  • Demodex mites can travel 8-16 mm per hour and yes, they actually do move around your face at night looking for mates! (I would so love to know whether you can feel the mites moving but I found no info on this)

So next time you are feeling lonely, just remember you’re never really alone. You’ll always have your mites.

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