What is demodex brevis?

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
  • sulfur

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.