Demodex and Pillowcases?

Demodex and the Common Misconception

When I tell my patients that they have demodex blepharitis, many of them assume they need to wash their pillowcases more frequently. It's an understandable conclusion that a mite living on the face, would use the pillow as a means of populating the face every night. This is however a crucial misunderstanding, and an opportunity to steer them towards a more (dare I say, actually) effective treatment. The mites demodex folliculorum and brevis live in the eyelash follicle and meibomian gland respectively. They are adapted to thrive on the human body and cannot survive off of it for very long. This simple fact should negate the idea that the pillow is acting as a reservoir to replenish the mites back onto your face. If a demodex mite did happen to navigate onto your pillow, by the time you came back to it, it should be dead. There actually has been very little said in the scientific literature about pillowcase washing and demodex mites, but what speaks loudly is the lack of evidence to say it IS beneficial. In fact, every major systematic review and practice guideline on this subject *does not mention pillowcases at all* (Donnenfeld et al., 2025; Lin et al., 2024; Rhee et al., 2023).

Why do we associate with pillows?

Most patients associate demodex with the only other "mite" that they know of- dust mites. Dust mites are highly ubiquitous in homes in arid regions, and live primarily on clothing, carpets, upholstry, and- you guessed it- bedding. For this mite, frequent washing of clothing and bedding is required for management. Interestingly, dust mites are roughly the same size as demodex brevis mites- measuring at 0.25 to 0.33 mm long (Fu et al., 2022; Lacey et al., 2009). The similarities end there however since their pathophysiology to humans is vastly different, and though they share the same phylum and class (Arthropoda and Arachnida) they diverge at subclass/ order (Acarina for Demodex, Acariformes for dust mites). In the end the confusion is a result of successful public communication on a different mite and a different condition. Rather than being frustrated by this unintended crossover in association, we can take hope that one day there will be the same type of universal awareness of demodex mites that live on the body and an understanding of the appropriate treatment course.

Bibliography

Donnenfeld, E., Nichols, K., Ayres, B., Farid, M., Gupta, P., Lindstrom, R., Pflugfelder, S., Starr, C., Venkateswaran, N., Gaddie, I., Karpecki, P., Koetting, C., McGee, S., Periman, L., & Yeu, E. (2025). The demodex expert panel on treatment and eyelid health (DEPTH) consensus regarding the preferred treatment for demodex blepharitis. _Clinical Ophthalmology_, _Volume 19_, 1893–1904. [https://doi.org/10.2147/OPTH.S525681](https://doi.org/10.2147/OPTH.S525681) Fu, Y.-T., Yao, C., Deng, Y.-P., Elsheikha, H. M., Shao, R., Zhu, X.-Q., & Liu, G.-H. (2022). Human pediculosis, a global public health problem. _Infectious Diseases of Poverty_, _11_(1), 58. [https://doi.org/10.1186/s40249-022-00986-w](https://doi.org/10.1186/s40249-022-00986-w) Lacey, N., Kavanagh, K., & Tseng, S. C. G. (2009). Under the lash: demodex mites in human diseases. _The Biochemist_, _31_(4), 20–24. [https://doi.org/10.1042/BIO03104020](https://doi.org/10.1042/BIO03104020) Lin, A., Ahmad, S., Amescua, G., Cheung, A. Y., Choi, D. S., Jhanji, V., Mian, S. I., Rhee, M. K., Viriya, E. T., Mah, F. S., & Varu, D. M. (2024). Blepharitis preferred practice pattern®. _Ophthalmology_, _131_(4), P50–P86. [https://doi.org/10.1016/j.ophtha.2023.12.036](https://doi.org/10.1016/j.ophtha.2023.12.036) Rhee, M. K., Yeu, E., Barnett, M., Rapuano, C. J., Dhaliwal, D. K., Nichols, K. K., Karpecki, P., Mah, F. S., Chan, A., Mun, J., & Gaddie, I. B. (2023). Demodex blepharitis: a comprehensive review of the disease, current management, and emerging therapies. _Eye & Contact Lens: Science & Clinical Practice_, _49_(8), 311–318. [https://doi.org/10.1097/ICL.0000000000001003](https://doi.org/10.1097/ICL.0000000000001003)