This is an automatically translated article.
Demodex dermatitis is caused by Demodex mites that live in the hair follicles of humans. To be able to diagnose whether you have an infection, doctors often use the Demodex test of fresh skin.
1. Overview of the fresh Demodex test
1.1. Dermatitis caused by the parasite Demodex
Demodex is a mite that parasitic and grows on human hair follicles, taking dead cells and sebum as food. Hair follicles in the forehead, cheeks, nose and eyelashes are the areas where these mites are mainly concentrated. Demodex causes an inflammatory skin condition caused by a parasite, called Demodex dermatitis (Demodicosis).
In humans, there are two main types of Demodex that cause disease, including: Demodex folliculorum and Demodex brevis.
Demodex folliculorum: This mite is usually 0.3 - 0.4 mm long, they choose to parasitize in small hair follicles, especially eyelashes, to eat dead skin cells. Demodex brevis: This mite is smaller than Demodex folliculorum with a length of 0.15 - 0.2mm, usually parasitizes in oil glands connected to small hair follicles, their food is glandular cells. Demodex life cycle usually lasts from 2 to 3 weeks. During the adult period, the ticks will find a mate and lay eggs in the hair follicles. After they die, their carcasses bring along bacteria that damage the skin.
1.2. What is Demodex smear test?
Demodex test is a method used in the diagnosis of Demodex infection in humans. Through this test, we can directly detect the morphology and concentration of Demodex parasites on the patient samples.
The microscopic test for Demodex causing dermatitis is very important for the treatment process. It helps to identify the cause of the patient's skin damage, recognize the presence and count the amount of Demodex. In the event that the test indicates that the patient has been infected with Demodex, the patient will be treated until the test does not detect the presence of Demodex.
Demodex soi tươi là xét nghiệm cho phép phát hiện bệnh Demodex ở người
2. Pathogenic mechanism of Demodex causes dermatitis
Studies have shown a number of mechanisms that cause inflammation of the skin of Demodex:
When Demodex dies, in their carcass a granulomatous reaction occurs with chitin; Demodex acts as a vector for bacteria, fungi to invade and cause disease.; Obstructed hair follicles due to increased Demodex density and keratosis at the neck of the sebaceous follicle; Demodex is rare in children under 5 years of age, usually with an adult onset; or cases of immunodeficiency, for example in patients diagnosed with HIV infection.
3. When should a fresh Demodex test be performed?
In patients with dermatitis caused by Demodex parasites, there will be certain symptoms, including:
Red patches appear on the surface of the skin; Skin vasodilation; Pustules begin to form on the skin; The affected area has a pronounced burning and itching sensation; Eyebrows, eyelashes and hair appear falling out;; Detected dilation of pores, thickened capillaries on both sides of the nose; Skin surface raised papules; Facial skin feels like crawling, especially at night and at night. Under the following conditions an increase in the number of Demodex mites is observed:
Demodex folliculorum - the skin surface becomes rough due to an increase in scale in the hair follicle; otitis externa ; Some cases of perioral dermatitis; Demodex abscess. If you are showing signs of parasitic dermatitis, you need to go to a medical facility soon to perform a fresh Demodex test to identify the disease and receive treatment soon.
Mụn mủ hình thành là một dấu hiệu cho thấy viêm da do ký sinh trùng
4. Fresh smear test to find Demodex causing dermatitis
In essence, the fresh Demodex test is a manual method using vegetable oil or KOH solution for the purpose of breaking down the stratum corneum, clearly showing the Demodex species causing inflammation and their movement.
How to perform the fresh Demodex test
Using KOH in the live Demodex test: Using 10% KOH to act on the horny epithelium, it makes them soft and thin, thereby revealing Demodex morphology. Using vegetable oil in fresh Demodex test: When the patient sample is dissolved in vegetable oil, Demodex's morphology becomes clearer, serving for observation. Specimen:
Using KOH in the Demodex test fresh: Scaly skin. Use of vegetable oils in the fresh Demodex test: Sebum. Procedure:
Use KOH in the test of fresh Demodex:
Add 10% KOH to the specimen; Lamen is covered, the patient is soaked in chemicals. Using vegetable oil in fresh Demodex test:
Put 1-2 drops of vegetable oil on the patient sample; Completely dissolve the residue into the drop of vegetable oil; Lamen is covered, the patient is soaked in chemicals. Evaluation of the results:
Body shape: The adult Demodex body will be divided into 3 distinct parts: Head, thorax and tail. Demodex brevis short tail; Demodex folliculorum long tail. Concentration density:
Considering the microfield X10, if the concentration of Demodex is from 5 animals or more: Demodex is the causative agent; In terms of microfield X10, if the concentration of Demodex is less than 5 animals: Demodex is not necessarily the causative agent. Dermatitis caused by Demodex parasites, if not detected, diagnosed and treated promptly, will leave dangerous complications. Therefore, when the body shows signs of infection, the patient should immediately go to a reputable medical facility to examine and perform a fresh Demodex test. The early detection of the disease helps to improve the effectiveness of treatment and promptly limit the consequences of parasitic dermatitis.
Vinmec International General Hospital is one of the prestigious medical facilities that perform diagnostic tests for parasites. The entire testing process at Vinmec and the examination is carried out by qualified specialists, experienced in diagnosing and treating diseases, so customers can rest assured and trust. thought.
Please dial HOTLINE for more information or register for an appointment HERE. Download MyVinmec app to make appointments faster and to manage your bookings easily.
