Demodex folliculorum and Demodex brevis are two species of tiny parasitic mites that live in the hair follicles and sebaceous glands of human skin, respectively. Both species are found primarily on the eyelashes and eyebrows or near the nose. Demodex infestation is relatively common, and is only rarely associated with disease. Occasionally, mite populations can expand, resulting in a condition called demodicosis, which causes itching and inflammation. Demodicosis most commonly occurs in individuals with a compromised immune system. Demodex are also implicated in some instances of rosacea, possibly due to bacteria carried by the mite, although the link between Demodex and this inflammatory skin condition is not fully understood.
Demodex brevis is a kind of mite found on humans. Like its counterpart Demodex folliculorum, brevis is naturally occurring. D. brevis is so small that you can’t see the mites with a naked eye. In fact, the average mite is only 0.15 to 0.2 mm long. They only cause noticeable reactions and problems in people if the mites exist in large quantities.
Symptoms of D. brevis usually only surface in cases of large infestations. Signs might include:
- red skin
- rough or tough skin
- scaly or patchy skin
The symptoms of D. brevis are similar to those of D. folliculorum. The key difference is location. While folliculorum tend to stay on the face, D. brevis can distribute all over the body. The chest and neck are common areas of D. brevis infestation, so you might notice more symptoms there if you have it.
Once in the skin, D. brevis feed off sebum in the oil glands. These glands are attached to hair follicles underneath the skin’s surface.
Infestations of D. brevis aren’t common in young children, but their numbers naturally grow with age. The mites may also be spread between humans.
Certain preexisting conditions can increase the risk of D. brevis, such as inflammatory conditions and infections. These can include:
Oily skin can lead to D. brevis because the mites feed off the oils under hair follicles.
Age also increases the prevalence of both kinds of demodex mites. For unknown reasons, D. brevis also tends to occur more in men than in women.
These mites are so small, you won’t know you have them unless you undergo testing at a doctor’s office. In fact, appointments for demodex diagnoses are rare because most people don’t even know they have them. People often discover they have demodex when they undergo further testing for other skin conditions.
To diagnose D. brevis, your doctor will conduct a biopsy. This consists of a small tissue sample scraped from your skin. Your doctor will then look at the sample under a microscope to see if any mites are present. They may also look for any other signs of skin disease that could be causing symptoms.
Usually, D. brevis doesn’t cause complications. However, extremely large amounts of the mites can lead to a condition called demodicosis. It occurs when there are more than 5 mites per square centimeter of skin. With demodicosis, you may notice pigmentation changes in addition to other D. brevis symptoms.
That said, D. brevis may sometimes exacerbate certain skin conditions, such as eczema.
In most cases, D. brevis isn’t severe enough to warrant significant medical treatment. Personal care is one of the main ways you can get rid of the mites and prevent widespread infestations. Follow these hygiene tips:
- Bathe daily to help remove excess oil that D. brevis feeds on.
- Take a shower immediately after working out.
- Use nongreasy lotions and sunscreen.
- Exfoliate your skin every couple of days to get rid of dead skin cells, as oils can become trapped under dead skin.
With these personal care steps, you may keep the mites at bay and avoid any further issues.
Clinical treatments for D. brevis are usually only necessary for widespread infestations or in cases of noticeable and uncomfortable symptoms. Your doctor may prescribe oral or topical medications to get rid of the mites. These medications get rid of the excess oils that the mites feed on and the dead skin cells they can hide under. These medications can also kill D. brevis eggs.
Your doctor may recommend creams and lotions with these active ingredients:
- salicylic acid
- benzyl benzoate
- selenium sulfide
Your doctor may also prescribe these medications:
If your doctor thinks a preexisting condition is causing D. brevis to flourish, you will also need to manage the underlying causes. An infection, for instance, may be treated with antibiotics or antivirals. Topical products may also be needed for eczema and rosacea.
Overall, D. brevis isn’t as common as D. folliculorum. It also doesn’t normally cause significant issues —you might have the mites and not even realize it. Personal hygiene can help keep demodex mites at bay and promote overall skin health. However, larger amounts of D. brevis can cause symptoms and warrant medical treatment. Clinically speaking, D. brevis is generally simple to treat.
Demodex brevis is a type of mite that lives in the oil glands of human hair follicles. It is closely related to Demodex folliculorum, another type of mite. Collectively, D. brevis and D. folliculorum are referred to as Demodex.
In some studies , Demodex mites have been found in 10 percent of skin biopsies and 12 percent of follicles. Other samples uncovered at least one species of Demodex in all adults tested.
The mites are microscopic, meaning they are not visible to the naked eye. While most people with D. brevis are not even aware that they are carrying these mites, those housing large infestations may experience symptoms.
Keep reading to discover the symptoms of Demodex brevis and the treatment options available to manage these mites.
Share on Pinterest Demodex brevis is a type of microscopic mite that lives in hair follicles.
D. folliculorum also inhabits the follicles. Unlike D. brevis, it is mostly found on the face and around the eyelids and eyelashes. It feeds on skin cells, whereas D. brevis feeds on oil called sebum in the oil gland cells.
D. folliculorum is different from other types of mites because it can increase the number of skin cells in hair follicles. This can give people the appearance of scaly skin.
The average D. folliculorum mite measures 0.3 to 0.4 millimeters (mm) in length, while the D. brevis is half that size, at 0.15 to 0.2 mm.
Most people with Demodex brevis are only carriers of the mites — they do not develop symptoms.
However, large infestations of the mites may lead to symptoms such as:
- red, scaly skin
- a rough texture to the skin, like sandpaper
- a burning sensation in the skin
Typical areas of infestation include the neck and chest.
D. brevis does not usually lead to complications, but large numbers of mites (over 5 per square centimeter of skin) may cause demodicosis.
Demodicosis is an inflammatory skin disease, with symptoms including:
- color changes in the skin
- scaly skin
- red skin
- sensitive or irritated skin
- rash with papules and pustules
- eye irritation
- loss of eyelashes
Demodex brevis has also been known to make skin conditions such as eczema and rosacea worse.
It should be noted that while demodicosis is dangerous in canines, there do not appear to be any reports of human demodicosis being life threatening.
D. brevis is acquired after birth through physical contact. Once on the body, the mites feed off the oil gland cells that are attached to hair follicles.
Numbers of D. brevis increase naturally, which may be why they are present in higher numbers in older adults than in children.
Anyone can have D. brevis. However, there are some factors that increase the likelihood and severity of a Demodex infestation.
Those with a weakened immune system (such as from HIV or cancer) as well as those with a potential genetic predisposition, may be more predisposed to higher levels of demodex and a resulting rash.
Older adults are also more likely to have Demodex mites and experience complications such as demodicosis.
Demodex brevis is most common in people aged 20 to 30 years because sebum levels are at their highest during that period. The mites are rarely seen in children under 5 years of age due to low sebum production.
Additionally, D. brevis and D. folliculorum seem to be more common in men than in women, although it is not clear why this is the case.
Most people are not aware they have Demodex mites living in their follicles. Many people only become alerted to their presence when being tested for other skin conditions.
It is not necessary for a person to get tested for the mites unless they experience symptoms or complications.
A doctor can diagnose demodicosis with a biopsy. This involves taking a small skin sample and checking it under a microscope.
The doctor will also ask about symptoms and look for other signs of the mites, such as scaly skin.
Demodicosis will be diagnosed if there is a high level of mites in the follicles in addition to skin symptoms.
Most cases of Demodex mites can be treated at home. Medical intervention may be necessary if someone is experiencing uncomfortable symptoms.
There may be several ways to minimize the number of D. brevis mites on the skin, and to reduce the risk of complications. Personal care tips include:
- bathing daily to reduce the oil secretions that feed the mites
- washing the hair and eyelashes with a mild shampoo
- using a non-soap gentle cleanser on the face twice daily
- avoiding oily cleansers, lotions, and sunscreens
If home remedies do not relieve symptoms or reduce mite numbers, then medication may be necessary to reduce excess sebum on the skin.
The medications for Demodex brevis and the mite eggs can be taken orally or applied to the skin. These medications are used off-label for this condition and include:
- benzyl benzoate
- oral or topical ivermectin
- topical metronidazole
- salicylic acid sulfide
- sulfur based medications
In severe cases of mites, or for people with weakened immune systems, a doctor may recommend oral ivermectin.
It is also important to manage any underlying conditions, such as immunosuppressing conditions like HIV, that may be contributing to high levels of mites.
While it may be unpleasant to think of mites living in the skin and hair follicles, they are usually harmless and do not cause symptoms in most people.
However, large numbers of Demodex brevis can lead to uncomfortable symptoms known as demodicosis. As a result, it is important to keep numbers under control through simple personal hygiene steps. However, for some individuals, a weakened immune system may be the provoking factor (not poor hygiene).
Those who are experiencing skin symptoms such as redness, itching, or scaling in areas where Demodex tends to exist in high quantities should consult their doctor about whether their rash is related to this specific mite.
What Causes Demodex Brevis?
Demodex Brevis spreads through direct contact between people. Once this mite has infested the body it resides on the hair follicles and feed on the sebum produced by the oil glands. These mites spread gradually and this is the reason why they are rarely seen in children and are more common in adults. Another reason for this is the production of sebum is much lower in children than adults. There are also certain risk factors which increase the likelihood of an individual having Demodex Brevis mites and even have complications arising out of it. 
These risk factors include having a history of acne. People with a weak immune system also are at risk for having Demodex Brevis. People with sparse hairs on the scalp are also at risk for getting Demodex Brevis. Elderly people who get Demodex Brevis tend to develop complications from these mites and develop a medical condition called demodicosis. This condition is characterized by presence of lesions which are red and can become itchy. 
Demodex Brevis is commonly seen in people between the age of 20 and 30. This is because the sebum production in people in this age group is at its peak. Additionally, males are known to have this mite more than females even though the cause behind it is not known. 
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