Where do Demodex mites live? - briefly
Demodex mites inhabit the hair follicles and sebaceous glands of warm‑blooded hosts, most frequently the facial skin of humans, particularly the eyelash and eyebrow regions. They are microscopic ectoparasites that feed on skin cells and sebaceous secretions.
Where do Demodex mites live? - in detail
Demodex mites inhabit the superficial layers of mammalian skin, primarily residing in hair follicles and associated sebaceous glands. Two species commonly found on humans illustrate distinct micro‑habitats: Demodex folliculorum occupies the infundibulum of hair follicles, especially those of facial hair, while Demodex brevis penetrates deeper into the ducts of sebaceous glands. Both species thrive where sebum production is high, favoring the face, forehead, cheeks, nose, chin, eyelids, and eyebrows. The mites also colonize eyelashes and the meibomian glands of the ocular region, where they feed on cellular debris and lipids.
Beyond the face, populations are detectable on the chest, upper back, and scalp, areas characterized by abundant follicles and oily secretions. They are absent from glabrous skin such as the palms, soles, and genital mucosa, where follicular structures are minimal. In the nasal cavity and ear canals, D. folliculorum may be present within the lining epithelium, exploiting the moist environment.
In other mammals, analogous Demodex species adopt comparable niches. For example, Demodex canis in dogs inhabits hair follicles and sebaceous glands of the trunk and limbs, while Demodex cati in cats prefers facial follicles and eyelid glands. These mites require a warm, humid microclimate and a steady supply of lipids, conditions provided by the host’s skin surface.
The life cycle—egg, larvae, protonymph, nymph, adult—occurs entirely within these protected follicular chambers. Eggs are deposited on the follicular wall, hatch in 3–4 days, and successive stages remain concealed until adulthood, when the mites emerge to feed and reproduce. This intimate association explains the high density of mites on sebaceous‑rich regions and their scarcity elsewhere on the body.