Demodex: face mites: normal residents, occasional trouble
Medically reviewed by Dr Sin Yong · Last reviewed · 3 min read
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
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.
Frequently Asked Questions
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.
