''Demodex brevis'' is one of the two species of face mite that inhabit humans (the other being ''Demodex folliculorum''). They are about half as long, at 0.15 to 0.2 mm (6 to 8 thousandths of an inch), as ''D. folliculorum'', but otherwise have few differences. Most of the article on ''

Demodex folliculorum ''Demodex folliculorum'' is a microscopic mite that can survive only on the skin of humans. Most people host ''D.folliculorum'' on their skin particularly on the face, where sebaceous glands are most concentrated. Usually, the mites do not caus ...

'' applies equally to ''D. brevis''. They are usually found in the

sebaceous gland A sebaceous gland or oil gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in ...

s of the human body. ''D. brevis'' reproduces in the sebaceous glands in the same way that ''D. folliculorum'' reproduces in the follicles. Under normal conditions, they are not harmful, and are considered commensals, whereby the mite benefits but there is no harm or benefit to the host, rather than

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

s where the host is harmed, or mutualistic organisms where the host benefits. During a severe infestation, though, there may be adverse effects on the host, such as

demodicosis Demodicosis , also called Demodex folliculitis in humans and demodectic mange () or red mange in animals, is caused by a sensitivity to and overpopulation of ''Demodex'' as the host's immune system is unable to keep the mites under control. '' ...

References

Trombidiformes Animals described in 1963 Parasitic arthropods of humans {{Trombidiformes-stub