In dogs,
Usually, the mites don't cause any harm. But too many can cause a skin condition called demodicosis (also called Demodex folliculitis).
Left untreated, the chronic inflammation associated with Demodex blepharitis can have many sequelae on the lid and the ocular surface, such as chronic hordeolum and chalazia. Chronic meibomian gland inflammation can lead to morphologic changes of the meibomian glands, gland atrophy, and meibomian gland dysfunction.
Too many Demodex mites can cause uncomfortable symptoms that may include: Itchy or burning eyes, especially in the morning. Swollen eyelids. Crusty eyes.
Demodex infestation is a commonly overlooked cause of ocular inflammation. Though true pathogenicity in humans is controversial, Demodex has been linked to many ocular conditions including blepharitis, conjunctivitis, chalazia, recurrent trichiasis, rosacea, and keratitis.
Symptoms include red or dry eyes, swollen eyelids, sticky lashes, itching, burning or stinging, grittiness in the eyes and crustiness around the outer edge of the eyelid. An infestation of mites can also cause dry and itchy skin, and it can even damage the oil glands at the edges of the eyelids and the lashes.
Common interventions used for Demodex infestation include metronidazole-based therapies, permethrin, benzoyl benzoate, crotamiton, lindane, and sulfur. Short courses of metronidazole taken orally have shown efficacy in reducing Demodex density.
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.
Life cycle
The six-legged larvae hatch after 3-4 days, and the larvae develop into adults in about 7 days. It has a 14-day life cycle[6] [Figure 2]. The total lifespan of a Demodex mite is several weeks. The dead mites decompose inside the hair follicles or sebaceous glands.
Direct contact or eggs present in dust as well as contact with infected towels, blankets, or sponges are the possible routes of Demodex spp. infection described in the literature [13, 14]. The use of facial creams or eyeliners has been considered as a potential route of Demodex spp.
"Demodex mites live on our skin and are especially prominent in areas where we have a lot of oil like the face or the middle of the chest." Even worse, said mites thrive in unsanitary environments, like Xu's dirty pillowcase.
Possible Impact of Demodex Diagnosis
Formication, a sensation resembling that of insects crawling on or under the skin, is a specific form of the general set of abnormal skin sensations known as paresthesias (prickling, tingling sensation of “pins and needles”) and tactile hallucinations.
If you can keep the follicles and lashes clean, the Demodex usually won't go into the lash follicle, he said. Regular lid hygiene can help with this, including using warm saltwater soaks, BlephEx, and agents like ivermectin.
Of all the treatment options investigated, tea tree oil has been shown to be the most promising option for killing Demodex mites (Liu 2010). Tea tree oil therapies may be more effective as they are known to have antibacterial, antifungal, and anti‐inflammatory properties (Liu 2010).
Among them, only Demodex mites are permanent ectoparasites of human and other mammalian pilosebaceous unit. A total of 140 species or subspecies have been identified worldwide in 11 orders of mammals including humans (1).
Generalized demodex will many times cause secondary bacterial infections. These bacterial infections will cause intense itching and a foul odor.
The mite, Demodex follicularum, spends its entire lifetime living in our skin follicles. In the daytime they feed on our oily skin secretions, at night they leave the pore to find mates, and find new follicles in which to have sex and lay their eggs. If the thought makes you want to wash your face, forget it.
Although domestic mites are well known allergens, they are also responsible for other, non-allergic, symptoms in humans, called acariasis. Little is known about acariasis, in which mites invade and parasitize the human body in various tissues from the gastrointestinal tract to the lung.
Medications typically used to treat demodex include metronidazole (topical),6 ivermectin (topical and oral), crotamiton (topical), and permethrin (topical).
A doctor may recommend treatment with creams such as crotamiton or permethrin. These are topical insecticides that can kill mites and so reduce their numbers. The doctor may also prescribe topical or oral metronidazole, which is an antibiotic medication.
However, when something – such as stress, illness, or old age – weakens your dog's immune system, the mites can multiply out of control and cause demodectic mange. Puppies are also most commonly affected while their immune system matures.
Demodex mites are found in about one third of children and young adults, half of adults, and two-thirds of elderly people. The lower rate in children is probably caused by immature sebaceous glands.
Gliding through grease, and protected by our pores, tiny Demodex folliculorum mites lead a secretive life within our skin, only emerging at night to mate on our foreheads, noses and nipples.