A Dermatologist's Perspective on Demodex Blepharitis: Causes, Symptoms, and Treatment Options

Katarina Kesty, MD, MBA, FAAD, Dermatologist and Medical Director at St. Petersburg Skin and Laser, weighs in on Demodex blepharitis, a condition characterized by inflammation of the eyelid margin caused by an overpopulation of Demodex mites, and discusses common symptoms, misconceptions, risk factors, and recommended treatment options.

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My name is Kat Kesty. I am a medical doctor and a board-certified dermatologist. Well technically, a double board-certified dermatologist. Board certified in dermatology as well as Mohs micrographic surgery. I own my own practice in St. Petersburg, Florida, where I see a mix of laser patients and Mohs patients, and general dermatology patients. I practice with my sister, who is also a board-certified dermatologist.

And one thing that we do a little bit differently than other dermatologists is we really do a lot of eye cases. So, we do a lot of Mohs cases around the eyes, we do a lot of laser cases around the eyes. We see a lot of crossover between ophthalmology and dermatology patients. And the reason for this is not only are we interested in the area of the crossover between dermatology and ophthalmology, but also both of our parents were ophthalmologists, so we grew up in an ophthalmology household. So, we're very familiar with the terms. And we will occasionally call our mom or our dad for a free consult on a patient from an ophthalmologist.

For a time, our dad was working for us here in the practice and he would just come in and help us with some Mohs around the eyes, some laser around the eyes, and some tough eye derm cases. But now he has fully retired, so it's just my sister and I working in the practice.

Can you provide an overview of what Demodex blepharitis is and how it differs from other forms of blepharitis?

Blepharitis in general just means an inflammation of the eyelid margin. There are lots of causes of blepharitis including immune reasons, infectious reasons, other things. So, when we're talking about Demodex blepharitis, we're talking about a blepharitis that is at least in part caused due to an overpopulation of the Demodex mite causing redness, swelling and inflammation at the eyelid margin, which is quite irritating to patients.

What are the common symptoms and signs of Demodex blepharitis, and how is it diagnosed?

Some of the common symptoms and signs of blepharitis in general are going to be itching, dry eye, crusting, scaling, some swelling, all of the common symptoms of the lid margin disease. How to diagnose blepharitis and especially Demodex blepharitis is with an exam with an ophthalmologist, or someone that knows how to use a slit lamp. And what they're looking for is kind of these cylindrical cones that fall off the eyelashes where the Demodex mites have lived and kind of shed their shell. And then it turns into these cones, which is very specific for the Demodex blepharitis. You can also take an eyelash off of a patient's eye or a little scraping, put it with some oil, and look at it under the microscope, and actually look for the Demodex mites themselves. That's another way to diagnose Demodex blepharitis.

What are the most common conditions that may be comorbid with Demodex blepharitis?

The most common conditions that are going to appear at the same time as Demodex blepharitis are going to be rosacea. Other common comorbidities are going to be seborrheic dermatitis. And then all of the other types of blepharitis so inflammatory, other infections, et cetera.

And the reason why something like rosacea comes with Demodex is when you have rosacea, you have disruption and dysfunction of the skin barrier. And we all have fungus, viruses, mites, bacteria that live on our skin just like we have it on our gut. We have a gut microbiome, we have a skin microbiome too, which changes based on whether you're talking about the nose, or the belly button or, in this case, the eyelid margin. We all have different populations of bugs that live on our skin and our eyes.

And so, what happens with Demodex is you get an overpopulation of a normal thing that's on your skin. So everyone has a certain amount of Demodex on their skin. What happens with Demodex blepharitis is it overgrows. And so, a comorbid condition like rosacea sometimes it's unclear what came first. Was it the Demodex overpopulation that caused the dysfunction of the skin barrier, which set off an inflammatory cascade leading to the clinical symptoms of rosacea? Or did you have the inflammation there which disrupted the skin barrier, which allowed the Demodex to overgrow? We're still not sure.

What are the risk factors for developing Demodex blepharitis, and are there any demographic trends associated with the condition?

Some of the risk factors include having any other type of inflammatory skin or eye disease, including the ones we just mentioned like rosacea and other forms of blepharitis. Other demographic trends associated with a condition include being older, older individuals, immunocompromised and smoking. All of those things can disrupt that skin barrier and lead to or possibly trigger an overgrowth of the Demodex causing the blepharitis.

In your experience, what are some common misconceptions or myths about Demodex blepharitis? In my experience, the most common myths surrounding

Demodex blepharitis is that it has something to do with the hygiene of the patient. So if you have Demodex blepharitis, sometimes patients will feel embarrassed or shame and feel like maybe it was due to them having poor hygiene. And this is just not the case. This is something that comes up in all socioeconomic populations of my patients and it is not associated with the hygiene of the individual.

What are the current recommended treatment options for Demodex blepharitis and how do they work? The recommended treatment options are going to be lid scrubs, occlusive ointments, topical steroids to help with inflammation, intense pulse light, which is an energy-based device. There are oral medications that are more appropriate for resistant cases or people with immunocompromised. And then, there's the new FDA approved treatment, which is twice daily for six weeks. That's also a good treatment for patients. And then, there's some topical tea tree oil treatments that have been shown to improve Demodex blepharitis.

Is tea tree oil an effective treatment option for Demodex blepharitis?

Tea tree oil is an interesting compound. If you look at the components of tea tree oil, there's a lot of different things that go into tea tree oil. This is not a substance like an Advil that only has ibuprofen in it. Tea tree oil has a lot of different active ingredients in it that is going to vary from formulation to formulation. For example, tea tree oil has been shown to help with separate dermatitis on your scalp and on your face as well. So it doesn't surprise me that it has some activity against Demodex blepharitis as well.

So is it an effective treatment? It is something that has been shown in some studies and some trials to help because part of the components of tea tree oil are going to be very anti-inflammatory and they also have shown that tea tree oil can have some... It can help decrease the populations of the bugs on our skin in general, which is going to help Demodex blepharitis.

Does treating this disorder present unique challenges due to being both an ophthalmological and dermatological disorder?

I think any diseases that sit in between two fields can be a challenge for both physicians and patients in terms of finding a physician that is comfortable diagnosing and treating. And then, also the two physicians often have to work together and communicate to take care of patients.

I'm very lucky to practice where I practice and have great ophthalmologist colleagues to consult with to take good care of patients. So that's something that I recommend. All dermatologists and ophthalmologists that are interested in treating this, have someone that you can call that is also interested in taking really good care of patients that may have a specific interest in this disease. And that's how I deliver the great care to my patients.

What advice or recommendations do you have for patients and health care providers in raising awareness about Demodex blepharitis and promoting early diagnosis and management?

If you, as a patient, if you think that or suspect that you may have Demodex blepharitis, my recommendation is to go see an ophthalmologist that can do a thorough slit lamp exam and maybe even an oil exam on you to see if they see any Demodex mites. There are definitely dermatologists that would be comfortable diagnosing and treating this. This may be something you have to call the office and see if they're comfortable treating before you go and see them.

In terms of giving advice to other healthcare providers, with a new FDA-approved medication, I think that's something that we should all be aware of and have in our toolbox for patients now that this is FDA-approved and the only FDA-approved treatment for Demodex blepharitis. And I think like all diseases that are emerging and we're becoming more aware of it, the most important thing, in my opinion, is to listen to the patient. And if they have a suspicion that they have this, then doing a thorough workup is definitely appropriate.

Are there any ongoing research or emerging therapies that hold promise in improving the management of Demodex blepharitis? What directions do you see future research taking in this field?

I think blepharitis in general is a really interesting topic and the intersection of dermatology and ophthalmology where we hit right at the lid margin is really interesting. I think I'm really glad that the drug was FDA approved for Demodex blepharitis. It's doing really well, which is great for patients. The tea rate oil I think is something that's interesting that we're going to be hearing a lot about in the next year or two because as we're discovering more and more about what those compounds are that make up tea tree oil, I think we're going to find some good uses for it, especially in dermatology. So I'm interested to hear and see the research on that.

I think the research on intense pulse light for blepharitis has been done and has been shown. And I think it'll be interesting to see how people adopt that procedure into their practice because I think that blepharitis in general, and especially Demodex blepharitis, it causes a lot of suffering for patients. And they really suffer when they have itchy dry red, swollen eyes. And I think as healthcare providers, we should do everything we can to help these patients that are suffering with blepharitis, including incorporating these three newer therapies: intense pulse light, tea tree oil, and then the newly approved FDA drug.

This transcript has been edited for clarity.