Demodicosis

Demodex are a small parasitic mites that live in the depths of the sebaceous glands and near the hair follicles. Demodex can be found in humans as well as in animals. Total of 65 different species demodex mites are known but only three of them (Demodex folliculorum, Demodex brevis and Demodex canis) are living in humans, other species of demodex mites live on the animals.

For the first time, demodex mite (Demodex folliculorum) was identified in 1842. Demodex folliculorum lives near or in the hair follicles. The second type of demodex mites living in humans the Demodex brevis, were first identified as a separate species in 1963. Demodex brevis lives in sebaceous glands. Both types of demodex mites are usually found on the face, around the nose, eyelashes, eyebrows, and may also appear in other parts of the body. Demodex canis, the third type of demodex mites, although rarely but still can be found in humans.

The size of an adult mite Demodex follikulorum only 0.3 mm - 0.4mm in length. Tick Demodex Brevis (Demodex brevis) is even smaller. The body of demodex is covered with tiny shells which allow the mites to stay in the hair follicles. Demodex mites have sophisticated digestive system which allows them to eat sebum deposited in the hair follicles.The demodex can also leave the hair follicle and stay on the skin surface, move around with speed about 8-16 sm / hour. They don't like the daylight therefore move only at night. Females mite are shorter and rounder compare to males. Demodex mites live only few weeks. During this time they lay eggs in the depths of the hair follicle and sebaceous gland. New mites usually born withing 3-4 days and the old demodex die decomposing in the hair follicles or sebaceous glands.

Our immune system can controll the "population" of demodex mites but sometimes, for differents reasons, the demodex start multiplying uncontrollably. Uncontrolled growth and presence in large number of one or all three types of mites demodex in humans may lead to the skin disease, often resemble in its symptoms to rosacea or acne. This disease called demodicosis and it needs treatment.