Demodex mites



Demodex mites bury themselves facedown near the root of the eyelash, creating a classical cylindrical dandruff at the base of the lash follicle in patients wearing eyelash extensions.

The most common microscopic ectoparasite living on the human skin is demodex.

Demodex is often present in healthy, asymptomatic individuals.

Demodex are parasitic mites.

They are opportunistic and provide positive benefits by ridding the eyelash area of waste.

Only D. brevis and D. folliculorum are found on humans.

The parasite is often transferref between host via contact of hair, eyebrows, and sebaceous glands on the nose.

It is suspected Demodex feeds on skin cells and sebum of the lid margin and pilosebaceous glands, that can trigger an inflammatory cascade.

The life cycle of an adult mite is usually two to three weeks.

The female Demodex mite lays 15 to 20 eggs within the hair follicle, which develop into larvae that eventually become adults in about seven days.

The mites contain 8 legs, and are capable of walking approximately 8 to16 mm/hour, and are typically more active in the dark, receding into the follicle with bright light.

High magnification slit lamp allows a visualization of the mites’ tails at the base of the eyelash follicle.

It may cause chronic anterior blepharitis, worsened meibomian gland disease and lipid tear deficiency.

D. folliculorum mites are about 0.4 mm in length and usually live in clusters on the face.

D. folliculorum is more associated with disorders of the eyelashes, contributing to chronic anterior blepharitis.

D. brevis mites are about 0.2 mm in length, and feed on sebaceous gland oils.

D. brevis burrows deep into sebaceous and meibomian glands, and is associated with causing posterior blepharitis, meibomian gland dysfunction.

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