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Are the mites having a party on your eyelids?

Do you wake up with early morning itching and irritation around your eyelids?  Have a lot of crusting build up around the eyelashes?

Your eyelids may be the unwitting host to be a nightly demodex mite party!

Demodex mites are the most common microscopic ectoparasite found in the human skin. The rate of Demodex infestation increases with age, being observed in 84% of the population at age 60 and in 100% of those older than 70 years (Post & Juhlin, 1963).

There are primarily two mites principally involved in human demodex infestation (demodiscosis); Demodex Brevis (D. brevis) and Demodex Folliculorum (D folliculorum).  D. brevis  is smaller 0.15-0.2mm and is found in the oil glands that are connected to small hair follicles.  D. folliculorum are found in small hair follicles, particularly the eyelashes and are 0.3-0.4mm in length.

These little "night ragers" are invisible to the naked eye, but their structure is clearly visible under a microscope. It has a semi-transparent, elongated body that consists of two fused segments.  Eight short, segmented legs are attached to the first body segment allow them to move 8-16 mm/h, mainly done during the night as bright light causes the mite to recede back into the follicle (Rather & Hassan, 2014). The body is covered with scales for anchoring itself in the hair follicle and the mite has pin-like mouth parts for eating skin cells, hormones, and oils (sebum) accumulating in the hair follicles.

The life of a mite is reasonably short, so the mite like to continue their family lines and copulate.  Both male and female Demodex mites have a genital opening and fertilization is internal. Mating takes place in the follicle opening and eggs are laid inside the hair follicles or sebaceous glands. The six-legged larvae hatch after 3-4 days, and the larvae develop into adults in about 7 days. It has a 14-day life cycle. The total lifespan of a Demodex mite is several weeks. The dead mites decompose inside the hair follicles or sebaceous glands .  So your lash area is a party ground, buffet restaurant and burial ground for your invisible friend!

Removed demodex mite with forceps under 40x magnification on examination slit lamp.

 

Refererences:

POST CF., JUHLIN E. Demodex Folliculorum and Blepharitis.  Arch Dermatol. 1963 Sep; 88():298-302.
 
Rather PA., Hassan I. Human Demodex Mite:The versatile Mite of Dermatological Importance  Indian J Dermatol. 2014 Jan-Feb; 59(1): 60–66.
 

 

 

 

 

Demodex Folliculorum under Scanning Electron Microscope

Demodex Follicolorum under conventional microscope 

Eyelashes with collarettes from Demodex Blepharitis

The same Eyelashes above after Blephex Clean

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