Most people have tiny mites that live on their face called Demodex folliculorum and Demodex brevis. Read on to find out what these mites do and how we pick them up, or watch our TikTok video.
@opti.labs Dr Tom Walker breaks down the truth about demodex mites; what they are, how we get them and what they do to our skin and lashes.
♬ original sound Opti Laboratories
Demodex mainly live around the base of facial hair follicles, especially around the eyelashes and eyebrows but they can be found elsewhere. They move around the surface of the skin then stick their head into the hair follicle, squeezing in beside the hair shaft, so that they can feed off the oil and protein produced by the sebaceous glands that are found half way down the follicle.
Each mite is tiny, being only around 0.3 to 0.4 mm in length with brevis being the shorter of the two types. This makes them just about visible under a microscope but invisible to the naked eye. The only time you would see them would be with an infestation, but that is rare.
Demodex mites are extremely common and they are likely feeding from your follicles as you read this!
Studies suggest that by middle age, most people carry at least some. Prevalence increases with age and nearly 100% of people over 70 harbour them. In most cases, they cause no problems and are considered part of the “normal” microbiome of the skin.
Some believe that they have a protective effect by consuming old sebum, preventing “bad” bacteria from having a place to infect. Others believe that they may be contributing to some common conditions as we will see later.
Opinions differ. Some believe Demodex are acquired in early life through close contact from parents. Others suggest they are found in the environment and we pick them up. They only live for for a few weeks and they quickly die when removed from the skin, but some believe that they can move between people from close contact, the sharing of towels, shared makeup or tools. Once established, they reproduce in follicles and remain as long-term residents.
In healthy individuals, eyelash mites are harmless – most people do not even know that they exist. Problems only arise when populations overgrow and when excessive, they can cause itching, redness, lash thinning, and crusting along the margin of the eyelid.
When severe symptoms occur then tea tree oil has been studied as an effective option. You can buy eyelid cleansing agents containing tea tree oil, usually around 5 to 20% concentration reduce mite counts and improve symptoms. Commercial eyelid wipes and foams with lower concentrations are now widely available and safer than DIY applications, which can be irritating if too strong.
Recent research has shifted our understanding of eyelash mites from “rare parasites” to near-universal human commensals. A 2022 review in Experimental and Applied Acarology confirmed that Demodex prevalence rises with age and may play a role in skin conditions like rosacea and chronic blepharitis. The review highlighted how mites can act as mechanical vectors for bacteria, carrying organisms such as Bacillus oleronius that may contribute to inflammation.
A 2023 paper in Cornea investigated Demodex in chronic blepharitis patients. Using lash sampling, they found mites in 80% of symptomatic patients versus 25% of controls, reinforcing the idea that mite density rather than mere presence determines symptoms. Treatment with tea tree oil lid scrubs significantly reduced both mite counts and ocular irritation scores.
Another study, published in Frontiers in Cellular and Infection Microbiology (2023), used advanced imaging to show how Demodex damage the follicular epithelium. The work demonstrated that overgrowth can disrupt the barrier, provoke immune responses, and worsen lid margin disease. Interestingly, the authors suggested that mite populations thrive when meibomian gland secretions are altered, hinting at a feedback loop between dry eye, gland dysfunction, and mite proliferation.
Finally, a 2024 clinical trial in Ophthalmology and Therapy tested a novel microblepharoexfoliation device combined with tea tree extract. Results showed superior reduction in mite counts compared with wipes alone, suggesting that future treatment may combine mechanical and chemical approaches.
Overall, the latest evidence paints a picture of Demodex as common companions that occasionally become disruptive tenants. Management should be considered when lash loss, lid margin irritation, or chronic blepharitis persists and tea tree oil remains the most evidence-based topical option.
A recent study published in the Turkish Journal of Parasitology investigated whether prolonged mask use during the COVID-19 pandemic influenced Demodex mite prevalence.
The authors note that prolonged mask use can create a warm, moist microenvironment on the skin surface that may promote mite settlement in some individuals, especially those prone to acne or seborrheic conditions. However, the prevalence in this young cohort remained relatively modest (7.5%), lower than typically reported in older adults.
This study highlights that while Demodex mites are nearly universal with age, in younger populations they are less common. Lifestyle factors (like mask use and skin microenvironment) may influence density, but “mask mandates” did not seem to greatly increase the demodex population.
There is generally nothing to worry about in regards to demodex. They are a normal part of a healthy biome that have their own role in the maintenace of healthy facial hair follicles.
References
Rhee MK, Mah FS, Jones L, et al. Demodex blepharitis: a comprehensive review of the literature. Clin Ophthalmol. 2023;17:2231-2248. [PMCID: PMC10351901]. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC10351901/
Maleki B, Fouladi R, Dehghani R, et al. Global prevalence of human Demodex mites: a systematic review and meta-analysis. Parasitol Res. 2025;124(6):1507-1520. [PubMed PMID: 40513697]. Available from: https://pubmed.ncbi.nlm.nih.gov/40513697/
Ataş M, Bakay B. Investigation of Demodex prevalence due to mask use after the COVID-19 pandemic with cellophane tape method. Turk J Parasitol. 2025;49(2):129-134. doi:10.4274/tpd.galenos.2025.43265. Available from: https://turkiyeparazitolderg.org/articles/investigation-of-lessemgreaterdemodex-lessemgreaterprevalence-due-to-mask-use-after-the-covid-19-pandemic-with-cellophane-tape-method/tpd.galenos.2025.43265
Zeytun E, Yazıcı M, Karakurt Y. The role of skin biophysical properties in Demodex mites proliferation: clinical study in acne, rosacea, seborrheic dermatitis and blepharitis. Acarol Stud. 2025;7(1):45-53. Available from: https://dergipark.org.tr/en/pub/acarolstud/issue/93955/1730644
Wang HY, Lai CC, Tsai IL, et al. Efficacy of terpinen-4-ol combined with eyelid deep cleaning in treating Demodex blepharitis. Transl Vis Sci Technol. 2024;13(2):12. Available from: https://tvst.arvojournals.org/article.aspx?articleid=2802258
Savla K, Tseng VL, Smith DL. Tea tree oil for Demodex blepharitis: a critical review. Cornea. 2020;39(2):224-229. [PMCID: PMC7388771]. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC7388771/