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Demodex aren't a problem with DemEx


Credit: Alan R Walker (talk) 09:16, 28 January 2014 (UTC), CC BY-SA 3.0, via Wikimedia Commons
Image of Demodex. Credit: Alan R Walker (talk) 09:16, 28 January 2014 (UTC), CC BY-SA 3.0, via Wikimedia Commons

These face mites or demodex are part of your natural eyelid and lash fauna, but if they get out of control you can have problems


These highly magnified images always look a bit scary, but demodex mites are a part of your natural eyelid and lash natural fauna so there is nothing to worry about. In fact, they are really quite useful as they feed on potentially harmful bacteria and old skin cells. But, if these mites start to multiply out of control it can be a problem for your eyelid and lash health. Too many mites can be a cause of blepharitis, an inflammatory condition of the eyelid which is associated with dry eye, in particular meibomian gland dysfunction.


What are demodex

Demodex is a tiny mite that lives in or around your hair follicles, including your eye lashes. For the vast majority of the time they are completely harmless. They do not light bright light so typically come out at night, this includes oils such as meibum, and lay their eggs in or around the hair follicle or gland ducts. Their life-cycle is just 14-days so it is easy to imagine how they can get out of control in your eye health is already compromised by dry eye.


Can you see them

There are two species of demodex found on your eye lashes - Demodex folliculorum and Demodex brevis. The largest D.folliculorum is 0.3-0.4mm long so in theory you may be able to see them but as they hide away in light this is unlikely. D.brevis is much smaller (0.15-0.2mm long) and this type tend to be found more often actually in the ducts of meibomian glands rather than round the lashes. You might notice what looks like dandruff on your eyelashes which could be a Demodex build-up.


How can you tell if you have a problem with demodex?

Because many of the symptoms, like dry, itchy red eyelids, can be attributed to other dry eye related causes demodex blepharitis is not aways identified straight away. However, an experienced eye care practioner specialising in dry eye will know what particular signs to look for: a build up of debris at the base of the eyelash (called collarettes) is a tell-tale sign that demodex is at work. This can be seen during a dedicated dry eye examination, even in the early stages, using their slit lamp biomicroscope and getting you to look down so they can get a good high magnification look at the edge of your eyelid and lashes.


Another important clue is that blepharitis caused by demodex will not respond to some traditional treatments such as antibiotics or long-term heat treatment. It is when blepharitis becomes intractable demodex is always suspected.


If necessary, any diagnosis can also be confirmed by microscopic analysis of an eyelash.


How do you ‘catch’ demodex

You are not born with these mites but by the time you are an adult it is likely that you will have some – estimates vary between 23-100% of health adults are affected. They are spread by skin-to-skin contact such as from mother to baby. The level of infestation on the eyelids increases with age, numbers jumping in around puberty as sebaceous glands proliferate, and by the time you reach the age of 60 the vast majority will be a host to these mini-parasites. By the age of 70 some experts put the level of infestation at 100%.


What problems do demodex cause?

When their numbers build up they can cause itchy, dry, red and inflamed eyelids, an inflammatory condition called blepharitis. They can also make dry eye worse by clogging up your meibomian gland ducts and reducing the flow of meibum (oil) to your eye’s natural oils. This oil slows the evaporative loss of moisture from your eye and without it your eyes can start to feel dry, sore and tired. If things are left unmanaged you may also notice the loss of some of your eye lashes.


How to you get rid of those pesky mites

Unless the mites have proliferated to a level where you are getting ocular irritation then nothing needs to be done. Getting demodex back under control and alleviating blepharitis and dry eye symptoms takes some effort on your part. Your eye care professional will need you to commit to a thorough hygiene routine.

This routine often starts with heat therapy to soften debris that may be blocking ducts to allow effective cleaning using a specialist cleanser with miticidal properties such as DemEx foaming cleanser. This non-sticky foam contains ingredients effective against both types of demodex but is gentle enough to be used every day.

It is generally recommended that this daily routine continues for approximately six weeks (allowing two full egg cycles to take place). You do not need to rid yourself completely, just enough to alleviate any blepharitis signs and symptoms.


Once the condition of your eyelids and lashes has improved then help to keep it that way by introducing a hypochlorous spray such as Purifeyes to your daily routine. Purifeyes helps reduce the bacteria count around the eyelids with the knock-on benefit of helping to prevent future demodex proliferation.


If you have suffered eyelash loss as a result of blepharitis then there are dry eye friendly restorative serums such as Lash Builder to help recovery. As not all ingredients are suitable for use by those affected by dry eye, the Dry Eye Zone offers a curated selection of tried and tested products. If in any doubt talk to your eye care professional.


If you are experiencing dry eye symptoms or suspect you may have Demodex blepharitis then you should ask the advice of your eye care professional. Do not leave things untreated as symptoms may progress.

Why not book your next eye examination with an independent practice today.



Sources:

Optometrists Network. How Does the Demodex Mite Cause Blepharitis? Dr. Russel Lazarus, August 27, 2020


Rather PA, Hassan I. Human demodex mite: the versatile mite of dermatological importance. Indian J Dermatol. 2014 Jan;59(1):60-6. doi: 10.4103/0019-5154.123498. PMID: 24470662; PMCID: PMC3884930.


American Academy of Ophthalmology. EyeNet Magazine. By Annie Stuart, Contributing Writer

Interviewing J. Daniel Nelson, MD, Henry D. Perry, MD, and Scheffer C. G. Tseng, MD, PhD. Managing Blepharitis: Tried-and-True and New Approaches. July 2012


Report of the TFOS Workshop on Meibomian Gland Dysfunction. Invest Ophthalmol Vis Sci. Special Issue. 2011;52(4):1917-2085.


American Academy of Ophthalmology. Dr Michael T Yen and Dr Cat Nguyen Burkat, MD. Demodex infestation. April 25, 2023.


Elston CA and Elston DM. Demodex mites. Clinics in Dermatology. 2014;32: 739-743.


Dr J Lappin. OCULAR SURFACE. The Ultimate Guide to Demodex Blepharitis. MAR 30, 2022



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