Demodex: hidden culprit if eye redness, itchiness, dryness is persistent despite usual lid hygiene techniques.

Demodex mite infestation is very common. Demodex folliculorum and Demodex brevis are ectoparasites with a very high prevalence of 100% in patients aged 70 years and older. Every person in this age group is estimated to carry a colony of 1000 to 2000 mites (see below reference). Still many eyeMDs are skeptical about its role in blepharitis, rosacea, dry eye, and allergic symptoms (see previous post). In short, this is because a couple of previous studies have failed to show a statistically significant benefit of treatment compared to controls. Newer studies are beginning to show Demodex is a real culprit that needs to be treated.

Here are some more pearls of information below that might help convince stubborn MDs that they should look for Demodex in all their blepharitis patients and treat them aggressively. 

1. Different patients respond differently to Demodex. These little critters like to sit head down sometimes burrowed into the hair follicle with their tails up and with the tails aligned along the lash at the root. Morning itching and irritation is very common with these mites because they hate light. They often come out at night and mate, lay eggs on the lashes, and then crawl back into the follicle in the morning, causing itching. Many people are allergic to the mites, causing severe itching and inflammation. 

2. Demodex also live in the nose and ear so that you must clean up the eyes and eyebrows and then keep them from finding the way back to the eye area with good hygiene and occasional touch-up treatments.

3. Treatments: Do not use full-strength tea tree oil. The patient must institute hygiene at home with tea tree shampoo scrubs and face wash and hair shampoo every day. 

There are many options to eradicate Demodex. The most popular in order of popularity is listed below. 
1. 1x per week: lid scrub with 50% Tea Tree Oil (TTO) & daily lid scrub with Tea

Tree Oil shampoo (1 part in 50 TTO shampoo in warm water). Cliradex also works very well. (Burning, itching, redness can occur with TTO: can be allergy or death of demodex mite; decrease frequency; stop if intolerable).
2.  Tea tree oil (50% strength) applied to the lid margin and lashes in three applications per session done at least three times, one week apart from each other.
3. Ivermectin-metronidazole combined therapy.
4. Ivermectin cream which is gentler than TTO but may be harder to get in pharmacy.

Details Below:

How to diagnosis Demodex:
1. Pull 2 lashes from each eyelid while looking under slit lamp. Be careful to watch the mite so it does not burrow back into the follicle. Sometimes, we need to reinsert hair follicle to allow mite to attach back to shaft. 
2. Under an optical microscope in 400 magnification, place a 20 µL drop of saline by pipette to the edge of the glass slide for lashes without retained dandruff. Can also use A drop of Fluress (fluorescein sodium and benoxinate hydrochloride solution, Akorn, Buffalo Grove, Ill.) on the lash to digest away some of the crust to makes it easier to see the mites.
3. For lashes with retained heavy dandruff, add 20 µL of 100% alcohol. 
4. Counted immediately for the former; for the latter, delay counting time up to 20 min to allow the cylindrical dandruff to dissolve and to stimulate the migration of embedded Demodex
5. Record total Demodex count  as the total number of mites found in a total of eight lashes per patient.


 2013 Jul;90(7):e198-205. doi: 10.1097/OPX.0b013e3182968c77.



*OD, FAAO †MS, OD, FAAO ‡OD Private Practice, Azusa, California (MMH); Omni Eye Surgery, New York, New York (KMM); Southern California College of Optometry, Fullerton, California (SES); and Private Practice, Pismo Beach, California (SES).



Demodex folliculorum and Demodex brevis are ectoparasites with an astounding prevalence of 100% in patients aged 70 years and older. Every person in this age group is estimated to carry a colony of 1000 to 2000 mites. With such a high prevalence, little attention has been paid to the mite among eye care practitioners. We demonstrate a clinical sequence in a set of case reports to identify the mite. The clinical sequence includes a clinical history of blepharitis, dry eyes, and/or ocular allergy; slit lamp examination of cylindrical dandruff; and confirmation using light microscope evaluation of epilated lashes.


Patient 1 was a 68-year-old woman who demonstrates associations with dry eyes and diabetes. Patient 2 was a 44-year-old man with uncommonly seen D. brevis present. Patient 3 was a 40-year-old woman with dry eyes and allergy, showing mite tails protruding from base of lashes. Patient 4 was a 60-year-old woman who demonstrates the association with rosacea. Patient 5 was a 53-year-old woman intermittently taking topical steroid and antibiotic combination medications, with an actual mite photographed on the surface.


Following a clinical sequence helps identify Demodex, the underdiagnosed, undertreated, and underappreciated ocular surface disease.

Published technique to treat:

 2012 Dec;27(12):1574-9. doi: 10.3346/jkms.2012.27.12.1574. Epub 2012 Dec 7.

Ocular surface discomfort and Demodex: effect of tea tree oil eyelid scrub inDemodex blepharitis.


Department of Ophthalmology, Chung-Ang University College of Medicine, Seoul, Korea.

TTO (Tea tree certified organic®, Sydney Oil Co, Sydney, Australia) was diluted with mineral oil into different concentrations. Weekly lid scrubs with 50% TTO were performed in the clinic, and daily lid scrubs with 10% TTO were advised for four weeks, according to the method reported by Gao et al. (). In brief, the clinic procedure was as follows: after applying a drop of 0.5% proparacaine, a cotton tip wetted in 50% TTO was used to scrub the lid margin and lash roots three times with a 10-min interval between each scrub. The patients were instructed to continue scrubbing daily at home and advised to close their eyes and massage their lids with medium pressure for three to five minutes using a cotton tip wetted in 10% TTO. After the treatment, the skin was rinsed with clean water and dried with a towel. We advised patients to perform home lid scrubs twice daily.

 2013 Jul 29. [Epub ahead of print]

Demodex Folliculitis Presenting as Periocular Vesiculopustular Rash.


Department of Ophthalmology and Visual Sciences, Yale School of Medicine, New Haven , Connecticut , USA.


Abstract Purpose: To report an unusual case of Demodex folliculitis presenting as periocular vesiculopustular rash. Design: Case report. Results: A 68 year-old woman presented with a unilateral periocular rash that was initially treated by her primary ophthalmologist with topical steroids and antivirals. Slit-lamp examination revealed severe bilateral blepharitis, right greater than left, with waxy sleeves around the eyelashes. The diagnosis ofDemodex infestation was considered. Treatment with daily lid scrub with polyhexamethylene biguanide (PHMB), 1,2-hexanediol and 1,2-octanediol (OCuSOFT PLUS) and erythromycin ointment twice a day resulted in complete resolution of the symptoms after 4 weeks. Conclusions: Ophthalmologists should be aware of Demodexand consider it in the differential diagnosis of periocular skin lesions.
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