Your face is home to approximately 2 million mites. That’s right! You really are the face of something much bigger than yourself!
Discovered in 1842 by German scientist Gustav Simon, Demodex Folliculorum is a microscopic mite (also called Facemite) that is known to only live on the human skin. It is classified under the Family Demodecidae, under the Genus Demodex- a genus containing about 65 species. Only two of these species- D. folliculorum and D. brevis– have been said to be related to humans.
While Demodex Brevis lives within the hair follicle of eyelashes and eyebrows, Demodex Folliculorum is known to inhabit the pores of human skin.
Originating from two Greek words, dēmos meaning “fat” and dēx, meaning “woodworm,” it is described as a “fat woodworm” when seen under a microscope.
Demodex Folliculorum are commensal species meaning they do not cause any harm. They survive off of human hair sebum whose production increases greatly during puberty. Even though most people believe that they are harmless, there is a minority school of thought that believe that Demodex Folliculorum could express some parasitic actions under certain conditions. In fact, when it was first discovered in 1842, it was classified as an ecto-parasite.
They are also said to colonize men more than women. That seems understandable considering the fact that at puberty, men tend to have more sebum production than women.
Another interesting fact is that they are transmissible- through contact and exposure to colonized dirt. Some examples of how his happens include through physical contact during activity, or through the close contact between infants and their mothers after which they rapidly colonize the rest of the infant’s body.
Demodex Folliculorum do not live for very long, usually around 20 days. During this time, they go through their entire lifecycle from eggs to adults without even pooping. At some point during this life cycle, opposite sexes meet at the entrance of a skin pore to mate. This results in the production of up to 24 eggs to ensure the continuity of our commensal neighbors.
In case the article makes your face a bit itchy, it is good to know that scientists believe that these commensals could be useful in defending against pathogenic bacteria for the human host. So, our friendly neighbors could be doing much more than we had had the chance to acknowledge.