Almost everyone carries microscopic mites on their skin. They live inside pores and hair follicles, feeding on skin oils and dead cells.
When people first hear this, the reaction is often disgust or alarm. It is easy to imagine infestation, poor hygiene or something going wrong.
In reality, these tiny organisms are a normal, lifelong part of being human and part of the natural balance of the skin.
Nearly all mammals host follicular mites that live inside the pores of the skin. They are absent only in monotremes, egg-laying mammals such as the platypus and echidna, which have different skin and mammary structures. In humans, mites inhabit hair follicles and sebaceous glands, feeding on skin oils and dead cells. Healthy skin can host large numbers without any symptoms.
These organisms exist in a symbiotic relationship with us. We provide a protected environment and nutrients, while their presence forms part of the wider community of microorganisms that helps the skin function normally.
We acquire our mites from our mothers through early close contact, including birth, breastfeeding and skin-to-skin care. Babies begin life with very small populations. Numbers increase through adolescence and adulthood, and by later life almost everyone carries them.
Creatures of the night
Humans carry two main species of follicular mite: Demodex folliculorum and Demodex brevis. Both are tiny, around 0.2 millimetres long, roughly a third to half the width of a typical human hair, and invisible to the naked eye. D. folliculorum tends to cluster near the openings of hair follicles, while D. brevis lives deeper within sebaceous glands. Both remain inside pores and are most active at night.
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At night, when levels of melatonin (the hormone that helps regulate sleep and circadian rhythms) rise, demodex mites move between pores and reproduce. This activity is microscopic and cannot be felt. Males and females mate at the openings of hair follicles, and several mites can share a single follicle without causing any symptoms.
Mites are not the cause of most skin problems. Evidence suggests they are opportunistic rather than causal. When inflammation or changes in the skin’s microbial balance occur, mite populations may increase because the conditions favour them.
Only in certain circumstances do demodex mites become linked with disease. In people who are immunocompromised, mite populations can increase dramatically and contribute to irritation and inflammation. Even then, they are usually part of a broader shift in the skin environment rather than the sole cause.
Rosacea sits in a similar grey area. People with rosacea often have higher numbers of demodex mites on affected skin, and some research suggests they may help sustain inflammation. But they are unlikely to be the original trigger. Rosacea appears to involve interactions between the immune system, the skin barrier, microbes such as bacteria and fungi, and environmental factors such as ultraviolet exposure, temperature extremes and stress, with mites sometimes contributing to that wider process.
Online forums are full of claims of “infestations” and advice on eliminating mites. Many of these claims are not grounded in science. Some people become convinced they can feel mites crawling on their skin. In certain cases this can be linked to delusional parasitosis, a mental health condition involving persistent sensations of infestation despite no medical evidence. The distress can lead to excessive scratching and skin damage.
Beyond the skin, humans interact with many other mites. House dust mites live in bedding, carpets and clothing, especially in warm and humid environments. They feed on shed skin cells and microscopic fungi. Some people develop allergies to proteins in dust mite waste. This reaction is caused by immune sensitivity rather than the mites attacking the body.
There are also mites that genuinely cause disease. Scabies mites burrow into the skin, causing intense itching and spreading through close physical contact. These infections are more likely where people are vulnerable, such as in overcrowded living conditions, limited access to healthcare or weakened immunity. Scabies is a medical condition, not a sign of poor hygiene or personal failure.
Understanding the difference between symbiotic mites and parasitic ones is important. Most mites that live with us are part of a natural system and do not need to be eliminated. Attempts to remove them aggressively with harsh chemicals or excessive cleansing can damage the skin barrier, leading to dryness, irritation and flare-ups of conditions such as eczema or acne.
In everyday life, simple hygiene is enough. Washing with water or mild products supports healthy skin without disrupting its ecosystem. Heavy use of strong cleansers or cosmetics may reduce mite numbers temporarily but does not necessarily improve skin health.
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There is one condition directly linked to high numbers of demodex mites called demodicosis. This occurs when populations become unusually dense and contribute to redness, scaling and rough patches. It is uncommon and usually associated with weakened immunity or existing skin disorders. Treatment focuses on restoring skin health and, when needed, using targeted medications rather than trying to sterilise the skin.
Our skin is not sterile. It is a living habitat that supports bacteria, fungi and microscopic animals. This community helps regulate inflammation, maintain balance and protect the skin.
Within that ecosystem, mites are not invaders but long-standing companions in a shared biological environment. In most cases, their presence simply reflects healthy, functioning skin.
Strange Health is hosted by Katie Edwards and Dan Baumgardt. The executive producer is Gemma Ware, with video and sound editing for this episode by Sikander Khan. Artwork by Alice Mason.
In this episode, Dan and Katie talk about a social media clip via TikTok from prettyspatricia.
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