Demodex is an iron mite (lat. Demodex folliculorum), which parasitizes in the sebaceous glands and glands of the cartilage of the eyelids, as well as in the hair follicles of humans and mammals.
The tick lives in the mouths of the hair follicles, especially in the mouths of the hair follicles of the eyelashes and eyebrows, in the ducts of the sebaceous glands of the skin of the face. However, it can also exist outside this environment. In an adult demodex, the body is transparent in color and has an oblong shape. The length of the tick is 0.1 – 0.4 mm. The body consists of 2 segments and is covered with scales that help the tick cling to the hair follicle; on the first part of the body there are legs and a “mouth”, with which he eats skin cells, sebum. The digestive system of this organism is so unique that it has no excretory openings. The life span of a tick is several weeks. During this period, he must have time to lay larvae in the hair follicles and sebaceous ducts. The larva develops over 2-3 days and in a week becomes an adult tick.
Demodex is considered an opportunistic microorganism, since it also lives in small quantities on healthy facial skin, especially if the skin is oily (it is found in about 96-98% of people). The activation of the activity of ticks and an increase in their number occurs under the influence of certain factors (weakened immunity, chronic diseases of the gastrointestinal tract, diseases of the endocrine system, stress), which causes the development of demodicosis.
A pathological increase in the number of microorganisms leads to the appearance of clinical symptoms of demodicosis: acne and rashes appear on the skin of the face, similar to the manifestations of rosacea and rosacea. Most often they are localized on the nose, forehead, chin, cheeks, sometimes on the eyelids. Subjectively, the patient may feel itchy skin. If demodex affects the skin of the eyelids, severe itching appears, redness of the eyes occurs, and eyelash loss may begin.
Patients often complain of severe itching of the eyelids, sometimes becoming unbearable, especially in the evening, heaviness in the eyes, redness and inflammation of the edges of the eyelids (blepharitis), scanty mucous discharge from the eyes, sometimes acquiring a foamy character. The subject of concern (and especially in women) may be the loss of eyelashes, the appearance of multiple white scales on them. In the future, inflammation of the edge of the eyelids is accompanied by inflammation of the conjunctiva, which causes the presence of complaints such as redness of the eye, tearing, and a constant feeling of a foreign body in the eye.