The tick that lives on everyone
Demodex is a tiny mite, about a third of a millimeter long, adapted to life in human skin. Two main varieties are known: one lives in the mouths of hair follicles, mainly on the face, the other - deeper, in the ducts of the sebaceous glands. It feeds on the contents of the sebaceous glands and dead cells, is active at night and does not tolerate light. The colonization of the skin occurs gradually from an early age, and by adulthood almost everyone has a mite - studies find it in the vast majority of adults.
That is why the phrase “you have been found to have demodex” is not a diagnosis in itself. You can find it in almost anyone, including those with flawless skin. Density matters: how many individuals are there per square centimeter of skin. The conditional limit is considered to be approximately five individuals per square centimeter, and only exceeding this threshold in combination with inflammation allows us to talk about demodicosis. The discovery of single ticks in a person without complaints does not require any treatment - this is the norm, not a find.
- Favorite habitats are the forehead, cheeks, wings of the nose, chin, external auditory canal, ciliary edges of the eyelids, and less often the chest and back.
- The tick is not transmitted through normal communication in the same way that infections are transmitted; Everyone has it, and it is impossible to “get infected with demodex” in the everyday sense
- It feeds on sebum, so it reproduces more actively where there are a lot of sebaceous glands and sebum secretion is increased.
- Lives for about two to three weeks, the entire cycle takes place in human skin
- Active in the dark, which partly explains complaints of increased itching and crawling sensations in the evening and at night
- The number of mites naturally increases with age and with increased oily skin
When does a tick become a problem?
Demodicosis develops when the balance between the mite and the skin is disturbed. Reproduction itself is usually secondary: first, conditions change - sebum secretion increases, local immunity weakens, the skin barrier is damaged - and then the number of mites grows. This is fundamental for treatment: if the background is not eliminated, any course will give a temporary effect.
- Rosacea and other chronic inflammatory diseases of the facial skin are the most common cause
- Seborrheic dermatitis and oily skin
- Long-term use of corticosteroid creams on the face is one of the most typical and most offensive reasons: they suppress local immunity and create ideal conditions for mite reproduction
- Decreased immunity due to chronic diseases, taking immunosuppressive drugs, after serious illnesses
- Diseases of the digestive system and endocrine disorders - as factors affecting skin condition
- Excessive care: aggressive cleansers, alcohol lotions, frequent peelings that destroy the protective barrier
- Oily, thick cosmetics that clog the mouths of the follicles
Manifestations of demodicosis are not dramatic, and this is the difficulty. The skin turns red, small nodules and pustules appear, peeling with small scales at the mouth of the hairs is characteristic, a feeling of tightness, itching, and sometimes a feeling of crawling under the skin in the evening. The skin looks lumpy, the pores are enlarged, and the face takes on an unhealthy hue. All this occurs in other diseases, so the only way to figure it out is not to look for symptoms on the Internet, but to take a scraping and evaluate the number of mites along with the overall picture.
Demodectic mange and rosacea: where is the confusion?
This is perhaps the most practically important section. Rosacea is a chronic facial skin disease in which the blood vessels are dilated, the skin is prone to redness, and in later stages papules and pustules appear. Clinically, it can look almost identical to demodicosis, and, more importantly, with rosacea, the number of mites on the skin is actually increased. Hence the endless disputes and confusion in appointments.
- With rosacea, the redness is persistent, worsened by heat, hot food, alcohol, physical activity and stress - this is a key distinguishing feature
- Rosacea is characterized by visible dilated blood vessels and hot flashes, while pure demodicosis is characterized by peeling at the mouth of the hairs and small nodules.
- There are no comedones, that is, blackheads, with rosacea; this helps to distinguish it from acne
- Demodex in rosacea is considered as one of the participants in inflammation, and not as the only cause
- Treatment with only acaricidal agents for rosacea gives incomplete results: blood vessels remain, hot flashes and a tendency to redness
- Treatment of rosacea alone, without taking into account the high number of mites, can also stall - therefore, they often act on both links
Practical conclusion for the patient: if after a course “from ticks” the face still turns red from a cup of hot tea, from a bath and from excitement - it’s not a tick, or rather, not only a tick. In this situation, it is not just another ointment that is important, but working with rosacea triggers: sun protection, avoiding hot and spicy foods, careful care, treatment prescribed taking into account the stage. Without this, a person goes around for years in a circle: “I treated demodex - it got better - it came back.”
When your eyelids suffer
The mite readily inhabits the ciliary edges of the eyelids, and there its excess manifests itself in chronic inflammation - blepharitis. This option deserves a separate discussion, because people have been treating “conjunctivitis” for years, using various drops and not understanding why their eyes continue to turn red.
- Feeling of sand, burning and heaviness in the eyes, worsening in the evening
- Itching along the edge of the eyelids, especially pronounced in the morning
- Eyelashes glued together after sleep, crusts and scales at their base
- Characteristic muffs are cylindrical formations around the base of the eyelash, clearly visible upon examination.
- Redness of the edges of the eyelids, sometimes loss and abnormal growth of eyelashes
- Recurring styes and chalazions
- Dry eyes due to disruption of the glands that produce the lipid layer of the tear film
Treatment of demodectic blepharitis is primarily eyelid hygiene, performed daily and for a long time. Warm compresses soften the secretion of the glands, a gentle massage of the eyelids helps remove it, and special means for cleansing the eyelash edge remove crusts and reduce the number of mites. The course is measured in weeks and months, not days, and the main reason for failure is stopping the procedures after a week, when it became easier. Products used on the eyelids are prescribed by the doctor: not everything that is suitable for the skin of the face is acceptable at the edge of the eye.
How is the diagnosis confirmed?
- Осмотр дерматолога с оценкой характера высыпаний, распространённости и фонового состояния кожи.
- Соскоб с поражённых участков кожи и микроскопия с подсчётом числа особей на квадратный сантиметр — количественная оценка обязательна, качественный ответ «обнаружен» неинформативен.
- Исследование ресниц: берут по несколько ресниц с каждого века и смотрят под микроскопом наличие клещей и характерных муфт.
- Дерматоскопия — позволяет увидеть хвосты клещей в устьях фолликулов и оценить сосудистый рисунок, что помогает отличить розацеа.
- Осмотр офтальмолога при жалобах со стороны глаз.
- При упорном течении — обследование на фоновые состояния: функция щитовидной железы, глюкоза, оценка состояния пищеварительной системы.
Treatment and what’s wrong with advertising “shampoo for demodex”
Treatment for demodicosis takes a long time - usually from four to eight weeks, sometimes longer, because several life cycles of the mite need to be blocked. There is no quick result, and this is the most common reason why people quit the course in the middle and think that the remedy does not work.
- External acaricidal agents that suppress ticks are the basis of treatment; The specific drug and regimen are determined by the doctor
- Systemic medications - only for severe, widespread and persistent cases, as prescribed
- Gently cleansing the skin twice a day without alcohol or abrasives; aggressive washing worsens the course
- Refusal of thick, oily cosmetics and hormonal creams on the face
- Daily hygiene of the eyelids if they are affected - warm compresses, massage, cleansing the eyelash edge
- Treatment of underlying disease: rosacea, seborrheic dermatitis, steroid dermatitis
- Changing pillowcases more often than usual and washing towels in hot water is a reasonable hygiene measure, although it is not critical
Now about what is being sold under the guise of solving the problem. Shampoos, soaps, “tar” products and creams that promise to get rid of demodex in a course are widely advertised, and some of them actually slightly reduce oily skin. But they do not significantly change the number of mites deep in the sebaceous glands, and most importantly, they do not affect the inflammation, which spoils the appearance. The danger here is not in the products themselves, but in the wasted time: while a person washes himself with special soap for six months, rosacea quietly progresses, and it becomes more difficult to return the skin to its previous state. The same applies to procedures that promise to “clean ticks” from the skin.