NANOCLUSTERING/SCIENCE PHOTO LIBRARY/Getty Images)
The question:
Is it true that there are little bugs living in our eyelashes?
The science:
Most of us have tiny bugs living on our faces, including in our eyelashes.
Demodex mites are tiny, partly translucent, cigar-shaped critters with eight legs, mouths and an affinity for our dead skin cells and oil. They can crawl, eat and lay eggs. And because they are so small — several could fit on a pinhead — we might never know they are there.
“I always tell my patients, ‘We’re never alone,’ ” said Melanie Mason, an assistant clinical professor of optometry at the University of California at Berkeley.
Unnerving as that may seem, it should not worry us too much. These mites are part of our normal skin microbiome, which also includes other microorganisms. They are usually kept in check by our immune systems, research shows, but sometimes can cause concerning symptoms such as redness, inflammation and burning, and vision issues.
When problems arise, however, the mites can be controlled with simple treatments, experts say.
Demodex mites often are acquired in childhood, transferred primarily through skin-to-skin contact with others. Their prevalence can increase with age and, according to one study, nearly 95 percent of people have infestations by age 72.
Two main species are commonly found on humans: Demodex folliculorum, which usually lives in hair follicles, including in eyelashes, and Demodex brevis, which usually lives in oil glands called sebaceous glands, eating dead skin cells and sebum, an oily substance that lubricates the skin. They also can be found on other areas of the face and, less commonly, elsewhere on the body, such as the groin.
These mites are not an issue unless the balance is thrown off between them and our immune system and they begin to multiply, causing symptoms.
An overpopulation around the eyes, for instance, is linked to blepharitis, an eye condition characterized by redness, itching, inflammation and, in extremely rare and severe cases, an inflammatory disease of the peripheral cornea called marginal keratitis. “However, it’s not completely clear to us yet what causes the overpopulation of mites in some people and which comes first: the overpopulation of mites or the blepharitis,” said Natasha Herz, an ophthalmologist and spokeswoman for the American Academy of Ophthalmology.
An overpopulation on other parts of the face is associated with some common skin conditions such as rosacea, which is not serious but presents as a long-lasting red rash on the forehead, cheeks and nose.
People who have eye-related symptoms such as redness, irritation, burning, tearing, crusting, and sticking of the eyelid or vision issues should visit an eye doctor. And those who experience facial redness with swollen, pus-filled bumps and small visible blood vessels — the telltale signs of rosacea — may want to consult a dermatologist.
Treatments may include facial scrubs and wipes containing low concentrations of tea tree oil (mixing your own concentration is not advised because high concentrations can be harmful to the eyes), a medicated eye drop for overpopulations around the eyes, and even certain antiparasitics and antibiotics for facial infections.
“We don’t aim to completely eradicate them. We aim to bring them down to a population that’s good for the patient,” Mason said. “It would be virtually impossible to get them off your body completely.”
What else you should know:
Demodex mites are not known to be related to personal hygiene, some experts say, but keeping your skin microbiome balanced may help prevent overpopulations.
- Wash your face, including your eyebrows and eyelashes, with a mild cleanser that is safe to use around the eyes. Moisturize your face, too.
- Do not share cosmetics, and change them out as directed. Demodex mites can survive in some types of makeup for short periods of time, research shows.
- Avoid sun exposure. Increased heat and sweat can cause greater oil production, which can provide more food for the mites, said Bruce Robinson, a dermatologist in New York City. “There is a delicate balance between the mites and our immune system that keep them in check. But obviously, if there’s more food, usually they’re going to overgrow,” he said.
The bottom line:
Demodex mites are common and can live asymptomatically on your face, including in your eyelashes. In some cases, however, they may cause symptoms and require treatment.