#102: Demodex Blepharitis and a New Study on Tea Tree Oil
Demodex mites. This is a tricky topic to bring up with my patients. The truth of the matter is that with age, we all have some Demodex mites living on our eyelashes. For some reason (science still isn't sure why) these mites are normal to have on our lashes.
Yet, this topic always gives my patients the heebie-geebies. I want to reassure you all that having them on your lids doesn't mean you are an unclean person.
And, going overboard trying to rid them from your eyes can cause more problems than just the irritation of having them. So, slow down. Don't freak out. Let's discuss these Demodex mites....
What are Demodex Mites?
Demodex is a small mite that buries itself into the follicles of the eyelashes and eyebrows. This mite is in the same family as the mite that causes mange in dogs. In small numbers, they don't do any harm to your eyes. It's when their populations increase that there can be problems.
These mites are nocturnal and usually do most of their activity while you're sleeping. At night, they eat the dead skin on your lids, lay eggs in the hair follicle itself and deposit wastes on the glands of the eyelids and lash follicles.
Having larger populations of mites in the hair follicles causes your lashes to become brittle, dry, break off easily and end up falling out.
How do you know if you have Demodex?
Scientists have not yet found out why, but some theorize that the demographics are playing a role by living on our lashes. We're not sure what it is, but since we have them, maybe they're supposed to be there. The problem isn't from their existence on our lashes, it comes when Demodex gets overpopulated. This is when you may start to feel symptoms, such as:
- irritation on your eyelids
- redness of eyes and especially at the lid margin
- itching at the base of your eyelashes
- eyelashes being misdirected or falling out
What can you do to get rid of Demodex?
Historically, eye doctors have thought that the best way to get rid of large populations of Demodex is to treat the lids with tea tree oil. For the last eight or so years, we have been treating Demodex both at home and in the office with tea tree oil-based treatments.
There are all sorts of products made with tea tree oil. At home, there are both eyelid and lash cleansing wipes and foam. In-office treatments involved using higher concentrations of tea tree oil painted onto the lashes while the patient's eyes were numb. This would allow the tea tree oil to penetrate deep into the hair follicles of the lids and kill them.
What's so good about Tea Tree Oil?
Tea tree oil is effective at killing the Demodex mites and it is a natural antibacterial. The Mayo Clinic says it can also be used to treat acne, athlete's foot, and nail fungus. Tea tree oil is also anti-inflammatory. It alleviates inflammation and can soothe the skin. It is a key ingredient in many facial scrubs and cleansers.
For many years, it was believed that tea tree oil, or more specifically, terpinen-4-ol, the active component of the Melaleuca plant, was the only ingredient that could kill these Demodex mites.
What's wrong with Tea Tree Oil?
In the summer of 2020, researchers from Harvard University published a study demonstrating tea tree oil having toxic effects on the cell of the meibomian glands. You can see the article here. It is these very same glands that we were using the tea tree oil on in order to try to eradicate the Demodex overpopulation.
The concentrations of tea tree oil that will cause damage to the meibomian gland cell is much lower than what's available in wipes and scrubs available over the counter. Tea tree oil has also been shown to indicated endocrine-disrupting properties. So, using it on your face or as a soap for your body is not recommended either.
CONCLUSION
If you have an itchy, scratchy feeling at the base of your lashes or your eyelids are red and irritated, you may be suffering from a Demodex overpopulation. Historically, eye doctors have used tea tree oil-based treatments to eradicate the mites.
A recent study has shown that tea tree oil is toxic to the meibomian glands and it is no longer recommended as a treatment. Stay tuned for the best way to get rid of Demodex mites in your lashes in a future blog. βIn the meantime, you an check out this blog to see what other lid and lash cleansers are available if you need to switch from the tea tree oil based cleanser you are currently using.
