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

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.






References:

Demodex.

Published technique to treat:

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

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. (12). 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.

Demodex Folliculitis Presenting as Periocular Vesiculopustular Rash.