Tiny creatures known as Demodex mites are a natural and often harmless part of human skin biology. Their presence is widespread, and for most individuals, they coexist without causing noticeable issues.
Understanding Eyelash Mites
The “bugs” on your eyelashes are specifically Demodex mites, primarily two species: Demodex folliculorum and Demodex brevis. These mites are microscopic, typically measuring between 0.15 to 0.4 millimeters in length. D. folliculorum is generally found in hair follicles, including those of the eyelashes, while D. brevis resides deeper within the sebaceous (oil) glands and Meibomian glands of the eyelids.
Demodex mites have an elongated, spindle-shaped body. They feed on skin cells and the oily substance called sebum produced by glands in the skin. Their life cycle lasts approximately 14 to 18 days, progressing through egg, larval, protonymph, nymph, and adult stages, with mating occurring near the follicle opening. These mites are common, with prevalence increasing with age, reaching nearly 100% in older adults.
When Mites Become a Problem
While Demodex mites are a normal part of human skin, an overpopulation can lead to a condition called demodicosis, or contribute to other eye and skin problems like blepharitis. This occurs when the balance between the mites, the skin’s microenvironment, and the human immune system is disrupted. Symptoms associated with an excessive mite population around the eyes can include itching, redness, and inflammation of the eyelids.
A gritty sensation in the eyes, a burning feeling, and crusting or debris along the lash line are also common indicators. An overgrowth can lead to eyelash loss or growth abnormalities, and a white sheen or cylindrical dandruff may be visible on the eyelashes. Factors contributing to an increased mite population include a weakened immune system, certain skin conditions like rosacea, poor eyelid hygiene, diabetes, long-term corticosteroid use, or chemotherapy.
Maintaining Eyelash Health
To prevent and manage an overgrowth of Demodex mites, daily eyelid hygiene is important. Gently cleansing the eyelids twice a day with a mild, non-soap cleanser helps remove excess oils and dead skin cells, which are food sources for the mites. Avoiding oil-based cleansers and greasy makeup can also reduce the favorable environment for mite proliferation.
If symptoms persist despite regular hygiene, consult a healthcare professional. They can diagnose demodicosis through a slit-lamp exam or by examining eyelash samples under a microscope. Professional treatments may include specialized eyelid cleansers containing ingredients like tea tree oil. For more severe cases, prescription medications such as topical or oral ivermectin or metronidazole may be prescribed to reduce mite populations and alleviate symptoms.