The Demodex mite is a type of parasite that lives on humans and can reside in hair follicles and sebaceous glands. These mites are arachnid (eight-legged) and invisible to the naked eye, varying in size from 0.1mm to 0.4 mm long. They typically live on the face and in the hair follicles of the eyebrows, eyelids, roots of the eyelashes, facial hair, and around the ears and are associated with various skin problems of the eyes and face, such as blepharitis and acne rosacea.
Demodex can affect humans at any age, but their presence increases in prevalence with increasing age. Immunity compromised patients such as diabetics, patients on long-term corticosteroids or chemotherapy, or patients who have HIV/AIDS also have increased risk and prevalence of Demodex infection. Usually, when the immune system is weakened and the parasitic population has colonized, this disease can badly damage the skin.
For transmission of mites from one person to another, direct contact of hair and sebaceous glands on the nose, or dust containing eggs is required. Since the disease processes begin when there is an overpopulation of Demodex, the vast majority of cases of mites go unobserved and don't show any adverse symptoms. However, in certain cases, the mite populations migrate and multiply in the eyelashes.
There are two existing types of Demodex mites: Demodex folliculorum, which live in the hair follicles and feed on skin cells and Demodex brevis, which live in the sebaceous (oil) glands and feed on the sebum (oil).
In the early stages, there are often no noticeable symptoms, but if left untreated Demodex infestation can worsen. Symptoms vary among patients and may include:
Demodex mites can be diagnosed by a slit-lamp (biomicroscope) evaluation and by carefully removing and viewing an epilated eyelash under the microscope.
Patients of all severity levels should also be instructed to discard their make-up, use hot water to wash their clothes and linens, and machine dry on HIGH setting WEEKLY.
Initial treatment involves the daily use of Tea Tree oil shampoos to wash the hair and all areas of facial hair. Patients with Demodex are also typically prescribed an eyelid cleanser (that contains tea tree oil or hyperchlorous acid) twice daily in order to eradicate the Demodex mites. They are instructed to cleanse the lids and lashes, as well as smear the lid cleanser onto the eyelash roots of both the upper and lower eyelid margin. Complete coverage of the eyelash base by the tea tree oil lid cleanser is necessary to be effective so that mites are unable to lay eggs and hatch more Demodex mites. Patients should be instructed to use the wipes on their eyelashes, forehead, eyebrows, and cheeks as the mites live in all of those areas and scrubbing the eyelids/eyelash area with an eyelid foam twice a day. Some common over the counter demodex treatments include:
For SEVERE CASES ONLY: Weekly in-office treatments may be necessary to manage a severe Demodex infestation. These treatments could include:
Patients diagnosed with Demodex need to follow a few simple instructions:
Immediately WASH bedding, pillowcases towels and clothes in HOT water and dry in a heated dryer on HIGH before beginning treatment, and REPEAT THIS WEEKLY thereafter.
Wash face, nostrils, hair, external ear and neck with a tea tree oil cleanser twice daily.
Scrub the eyelids with a demodex eyelid foam and wipes twice a day.
Avoid using makeup for at least 1 week and discard all old makeup.
Avoid oil-based cleansers, greasy makeup, lotions, and sunscreens which can provide further "food" for the mites.
Exfoliate face once or twice a week to remove dead skin cells and trapped sebum. Keep pets away from sleeping surfaces.
With the proper medical care, treatment, and hygiene, the Demodex count usually drops to zero in 4-6 weeks without recurrence in the majority of cases. Patients receiving therapy show dramatic improvements in symptoms, eye inflammation, tear film stability and vision.