Demodecosis is a lesion of smooth skin and hair by a microscopic tick of the genus “demodex”. It begins with the appearance of skin rash, acne, ulcers on the skin of the face, chest, back, increased greasiness of the skin, itching. Further progression of the disease leads to pronounced cosmetic defects: the skin acquires an earthy-gray color, becomes bumpy, a puffiness of the nose appears, facial movements of the face become difficult. If the hair is affected, itching, hair loss and eyelashes. It is dangerous by the addition of secondary infection, scarring of the skin, progression of the disease.
Etiology and pathogenesis
The tick Demodex folliculorum, which causes demodecosis, was discovered in 1842. To date, 65 species of mite are known, but only three of them affect humans, the rest are parasitic only on animals. The habitat of the tick is the sebaceous gland and hair follicles; the favorite place of localization is the chin, nose; demodecosis can occur on the eyebrows and eyelashes, in the latter case blepharitis develops.
The size of an adult is about 0.3-0.4 mm, and its body is covered with scales, thanks to which the tick is firmly fixed in the hair follicles. The tick feeds on sebum and human hormones. Ticks avoid daylight, and therefore they come to the surface of the skin only at night, which explains the itching and discomfort with demodecosis, which increases in the evening.
The life cycle of the causative agent of demodecosis is several weeks, during which time the female is able to make more than one clutch of eggs, and the number of eggs in a clutch can reach several dozen. After 3-4 days, new individuals appear, which in a week are already ready for reproduction. Old individuals of the tick die and decompose in the hair follicles.
The demodex tick is found in 90% of the population, but in some people it does not cause demodecosis, while others cannot be cured for a long time. If single individuals are found in the follicle, then this is not a cause for concern, in this case the causative agent of demodecosis is inactive and practically does not reproduce.
The trigger mechanism when the tick begins to multiply rapidly is not fully understood, but people experiencing stress, nervous overstrain fall into the risk group, because all this activates the production of sebum, which creates favorable conditions for the tick’s vital activity. A decrease in immunity, a tendency to skin diseases, spicy food, prolonged insolation, a passion for baths and saunas also causes activation of the causative agent of demodecosis.
In addition, the use of cosmetics containing hormonal drugs in many women eventually leads to demodecosis, since hormones and nutrients in creams are his favorite food. With this way of infection, demodex individuals get into a jar of cream every day, and then the cream does not bring beauty and youth, but a serious disease. Of course, demodecosis does not entail deep violations, but the skin of the face deteriorates, besides, with extensive lesions, secondary infection with pathogenic microflora is possible, which further complicates the course of demodecosis.
Women with loose and sensitive skin prone to redness are at risk, most often they are blondes or brown-haired women. In men, demodecosis is less common, this is due to shaving, since the keratinized layer of the skin is removed almost daily and the tick cannot strengthen in the layers of the skin.
If the human immune system is not disturbed, then demodecosis does not occur, since the parasite does not penetrate beyond the basement membrane, but if hormonal drugs are taken or there are conditions in which the immune system is activated, then the skin structure changes and the probability of demodecosis increases dramatically. The combination of all or several pathogenetic mechanisms increases the likelihood of the disease, although it is not uncommon that demodecosis is diagnosed in people who do not fall into any risk group.
The main manifestation of demodecosis is the inflammatory processes of the skin of the face. And, if the usual anti-acne cosmetics do not have an effect, but instead the number of pink acne, pimples increases, sebum secretion increases, the complexion becomes unhealthy (from gray to purple shades), then a microscopic examination of the demodex of the contents of the hair follicles should be carried out.
Clinical manifestations of demodecosis depend on the number of actively reproducing individuals, on the general condition of the body and on the type of skin, improper facial skin care is also of great importance in the development of symptoms. There is a classification of demodecosis, depending on the type of rash, but most often demodecosis manifests itself in various forms of rash. Also, the form of demodecosis indicates the severity of the process.
It is characterized by redness of the face and isolated rashes, in this case demodecosis should be differentiated from rosacea. The cause of rosacea is vascular neurosis and the attachment of bacterial microflora. Demodecosis can complicate the course of rosacea, but it is not the cause of its occurrence.
The formation of pustules is possible, they are formed due to the overflow of follicles with sebum, which later becomes infected a second time. Papules with demodecosis are most common. Their size ranges from 0.5 to 2 mm. As a result, the face is strewn with various elements from pink to dark red.
Rashes cause discomfort to patients, many try to get rid of them mechanically, and therefore, in addition to inflammation, you can see dried crusts and cyanotic infiltrative areas. The inflammatory process provokes excessive growth of epithelial cells and disrupts natural exfoliation, the skin layer thickens, which creates even more comfortable conditions for the progression of demodecosis. The pathogen multiplies most actively in the spring and autumn periods, and the seasonality of relapses is associated with this.
The condition of the skin in demodecosis contributes to the development of other skin diseases. The symptoms of rosacea, simple acne and dermatitis also become brighter. If demodicosis of the eyelids is observed, then blepharitis and conjunctivitis join.
Scratching and constant injury to the skin due to the desire of patients to remove rashes mechanically, can lead to a widespread pustular infection, which, unlike demodecosis, affects various parts of the body.
One of the complications can also be called isolation and the inability to lead a former lifestyle due to a poorly aesthetic appearance, in some cases this can lead to psychoses and psychoneuroses. Patients diagnosed with demodecosis have a history of chronic diseases of the digestive system, endocrinological disorders, as well as the presence of foci of chronic infection.
Treatment and prevention
Demodecosis is a chronic disease with periods of remission and exacerbations. It is impossible to completely cure it, but it is possible to achieve a long and stable remission when the skin condition is clinically healthy.
The use of antiparasitic drugs is not always advisable. Since the features of the life cycle of the causative agent of demodecosis are such that long courses of antiparasitic therapy are required. And almost the only drugs that can treat demodecosis are drugs of the tinidazole and metronidazole groups. But in order to achieve the desired concentration in the skin, it is required to take high dosages, which adversely affects the liver and the function of hematopoiesis.
Gel preparations containing metranidazole are quite effective, since due to their structure they are able to penetrate into the deep layers of the skin, do not contain fat, in the presence of which the causative agent of demodecosis begins to multiply more actively, have a cooling and moisturizing effect. Alcohol and ether “chatterboxes” made in a pharmacy by prescription are effective for deep skin lesions with demodecosis. Their short-term use is detrimental to the main number of parasites. But with prolonged use, alcohol and ether cause dry skin, in response to this, sebum production increases. And demodicosis breaks out with renewed vigor.
The most productive treatment of demodecosis consists in joint therapy by a dermatologist and a dermatocosmetologist. In this case, medications affect demodex, and cosmetic procedures restore the protective functions of the skin to a state where the skin can cope with the parasite on its own. Thus, electrophoresis with moisturizing substances has a beneficial effect, when the action of electricity temporarily blocks the activity of the tick, and moisturizing preparations penetrate into the deep layers of the skin, thereby revitalizing it and reducing sebum production.
A course of microdermabrasion with demodecosis in remission, when there are not so many rashes and inflammations, helps to mechanically remove the layer of skin with the greatest localization of ticks. Non-hardware facial cleansing is also shown. And the subsequent peeling of the face with fruit acids, acidifying the skin, in principle prevents the appearance of inflammation and the recurrence of demodecosis.
After a complete clinical cure from demodecosis, a course of laser coagulation or photocoagulation of vascular defects is recommended, since due to prolonged and intense exposure to drugs and complex cosmetic procedures, the capillaries in the face area expand, and sometimes a new capillary mesh is formed. The blood flow increases, which means that the skin temperature also increases, which provokes the production of sebum, this can again serve as a trigger for a relapse of demodecosis. In addition, patients should be examined by an endocrinologist, review the diet, it is better to switch to dairy and vegetable food during treatment.
Before starting the treatment of demodecosis, it is necessary to get rid of all cosmetics and accessories (powder brushes, lipstick brushes) and avoid using decorative cosmetics throughout the treatment. To moisturize the skin, use light gels, preferably in single packs or in a container with a dispenser to prevent mites from entering the bottle. It is recommended to change bed linen daily and wash pillows and blankets more frequently, followed by ironing on both sides, since temperature effects are detrimental to the causative agent of demodecosis.
There is also a special therapeutic cosmetics, which is widely offered to patients with demodecosis everywhere with a guarantee of 100% results, but no confirmed statistical data on its effectiveness has yet been provided by any of the cosmetic companies. Treatment of demodicosis is long-term, because for each patient it is necessary to select an individual scheme.
There is no specific prevention of demodecosis, but if you follow the diet, properly care for the skin, do not use someone else’s cosmetics, then the probability of getting demodecosis decreases sharply. Patients who have achieved stable remission should switch to plant foods in the spring and autumn during exacerbations of demodecosis, pay more attention to the condition of the skin and carry out preventive measures by visiting a dermatocosmetologist.