Published 13 October 2026 · Reviewed by Dr Sin Yong
Demodex are microscopic eight-legged mites, under half a millimetre long, that live in the follicles and oil glands of most adult faces and usually cause no problem. Two species live in human skin: Demodex folliculorum in the follicle and lashes, and the smaller Demodex brevis in the gland. They matter when numbers rise well above normal, a condition called demodicosis, which causes itch, burning, scale and acne-like bumps and overlaps with rosacea. Treatment reduces the overgrowth; eradication is not necessary.
Key facts
Species
Demodex folliculorum (0.3–0.4 mm, in the follicle and lashes) and Demodex brevis (about half that size, in the oil gland)
When they matter
Demodicosis: mite density well above normal, commonly defined as more than five per square centimetre
Rosacea link
Mite numbers are higher in rosacea and likely add to the inflammation, but are not its sole cause
Treatment aim
Reduce overgrowth and inflammation with prescribed topical agents such as ivermectin and a simpler routine; eyelid involvement is managed with an eye specialist
Illustrative image, not a patient.
Where Demodex matters on this site
Demodex comes up on this site wherever a red, bumpy or itchy face has not behaved as expected, because overgrowth is one of the things that keeps rosacea-like skin from settling.
Everyone has face mites; the question I ask is what has let them multiply, because that is what treatment has to change.— Dr Sin Yong
Face mites (Demodex): the full article on when mites become a problem, how demodicosis is diagnosed and how it is treated in principle.
Acne treatment: where comedones point to acne rather than to mites, and why the two are managed differently.
Across those pages the useful question is the same: not whether you have face mites, but whether their numbers have outgrown what your skin tolerates.
Not to be confused with
Demodicosis overlaps with several conditions, and the distinction changes the treatment.
Rosacea. Mite numbers are higher in rosacea and likely add to the inflammation, but they are not its sole cause. Flushing and fixed redness point to rosacea; itch and fine scale point towards mites.
Acne. Acne has comedones, the blackheads and whiteheads. Demodicosis does not.
Fungal folliculitis. Itchy, uniform bumps of a yeast overgrowth, often on the chest, back and forehead.
Perioral dermatitis. Small bumps clustered around the mouth with a clear margin at the lip, often after steroid creams.
House dust mites. A different creature that lives in bedding and household dust and triggers allergy. It does not live in human skin.
Excluding look-alikes is part of the diagnosis, which is made by examination, dermoscopy or a standardised skin surface sample rather than by a home test or a product label.
What decides whether Demodex matters for you
Almost every adult carries Demodex, so treatment depends on symptoms and on what is letting numbers climb.
Your symptoms. Itch, burning, fine follicular scale on a red background and flaking at the lash line are the typical presentation.
Response to rosacea treatment. A rosacea-like flare that does not respond as expected is the classic prompt to look for mites.
Steroid creams. Long-term facial steroid use favours overgrowth and is one of the first things asked about.
Your routine. Heavy oil-based cosmetics and a disturbed barrier both encourage overgrowth; harsh scrubbing and home remedies make it worse.
The eyelids. Lash-line involvement is managed with an eye specialist.
Treatment aims to bring numbers back to normal and settle inflammation. Eradication is neither possible nor necessary, and the plan is reviewed rather than fixed, as the rosacea page explains for the wider condition. Oral treatment is reserved for extensive disease.
Where it fits
Almost every adult carries Demodex, so the useful question is never whether you have face mites but whether their numbers have outgrown what your skin tolerates. Overgrowth is favoured by long-term facial steroid use, heavy oil-based cosmetics, a disturbed barrier and reduced local immunity. Dr Sin Yong checks for Demodex in rosacea that has stalled, because a rosacea-like flare that does not respond to usual treatment, with itch and flaking at the lash line, is the typical presentation; diagnosis is by examination, dermoscopy or a standardised skin surface sample. Harsh scrubbing, neat tea tree oil and home 'mite killers' make it worse. Full page: face mites; the condition it overlaps with on rosacea; another look-alike on perioral dermatitis.
Related on this site
Pharmacy steroid creams such as Xepacort cream, and their risks on the face, are explained in the Skin A–Z.
Frequently Asked Questions
Neat tea tree oil and home mite killers tend to irritate the skin and can make demodicosis worse. Where treatment is needed, prescribed topical agents with activity against mites, such as ivermectin, are the usual starting point, alongside a simpler routine. The aim is to reduce overgrowth and inflammation, not to eradicate Demodex, and the plan follows a doctor’s assessment of the pattern and its severity.
Yes. Demodex folliculorum lives in the follicles of the lashes as well as the face, and overgrowth there can cause itch, flaking and crusting at the lash line. Eyelid involvement is managed together with an eye specialist, because the treatments used on facial skin are not all suitable near the eye. Lash-line symptoms alongside stalled rosacea are a common reason to look for mites.
Almost every adult does. Demodex are rarely found in children under five and become more common as oil production rises, concentrating on the forehead, cheeks, sides of the nose, eyelids and ears. A normal population causes no symptoms and needs no treatment.
No. They are normal residents of adult skin. Demodicosis is a question of density and of what is letting numbers climb, such as steroid creams or a disturbed barrier, not of how often the face is washed.
Recommendations for Rosacea Diagnosis, Classification and Management: Update from the Global ROSacea COnsensus 2019 Panel. British Journal of Dermatology (PubMed), 2019. pubmed.ncbi.nlm.nih.gov
