Demodex Blepharitis

Demodex blepharitis is a type of eyelid inflammation that’s due to an overgrowth of tiny parasites called Demodex mites. These mites live naturally on human skin, including on your face and eyelids, and normally don’t cause problems. But if they grow too numerous, they can cause itchy eyes, swollen eyelids and other symptoms that can disrupt daily life and threaten eye health. Treatment can get rid of the excess mites, relieve symptoms and prevent complications.

Demodex blepharitis is the most common form of blepharitis. Some experts estimate it may affect 25 million people in the U.S. This condition affects people of all ages, but it’s especially common among adults over age 65.

Signs of Demodex blepharitis

The most common symptom of Demodex blepharitis is itchy eyes. Your eyes might itch off and on throughout the day, or even constantly. Because the mites are most active at night, you might have the worst itching in the late evening or early morning.

Besides itchy eyes, other symptoms include:

• Dry or irritated eyes
• The feeling that there’s something in your eye (foreign body sensation)
• Swollen or puffy eyelids
• Red/discolored eyelids
• Red/discolored eyes (the white part)
• Crusty bits or flakes on your eyelashes
• Eyelids that feel stuck together, especially when you wake up in the morning
• Eyelashes that grow in odd directions
• Loss of eyelashes

These symptoms may make it hard for you to focus or see clearly. You may find yourself blinking or rubbing your eyes to try to relieve the symptoms. But with each blink, it might feel like something is rubbing against your eye that just won’t go away. These sensations can be distracting and frustrating.

Demodex blepharitis causes

Tiny parasites called Demodex mites cause Demodex blepharitis. They naturally live on everyone’s skin. Usually, they coexist with us peacefully. But sometimes, often for unknown reasons, they grow too numerous. A mite overgrowth damages the delicate skin along your eyelids and triggers inflammation, leading to symptoms.

Two specific species are responsible for Demodex blepharitis:

• Demodex folliculorum (D. folliculorum): These mites live in your eyelash follicles (the structures that eyelashes grow out of) near the surface of your eyelid. You might also hear them called “eyelash mites.”
• Demodex brevis (D. brevis): These mites live in your meibomian glands, which are located in the skin along the edges of your eyelids. The glands produce oil that makes up part of your tear film.

These mites also live elsewhere on your skin, including your cheeks, nose, forehead, scalp, neck and chest. But they’re so tiny you can only see them under a microscope. D. folliculorum mites are less than half a millimeter in length. D. brevis mites are less than a third of a millimeter. The typical lifespan for a mite is about three weeks. But they lay eggs in your eyelash follicles, allowing for continued reproduction.

Risk factors

Anyone can get Demodex blepharitis. People who are young and have no known risk factors develop this condition. But you have an increased risk if you:

• Are over age 65
• Are under stress
• Have rosacea
• Have diabetes
• Have a suppressed immune system
• Smoke
• Drink excess alcohol
• Spend a lot of time in the sun
• Wear contact lenses

Experts haven’t yet determined if Demodex blepharitis is transmissible between people.

Co-occurring conditions

Many people with Demodex blepharitis also have dry eye disease. There’s a strong link between these two conditions. Experts believe that because dry eye disease harms your eyes’ natural tear film, it may create an environment where the mites can flourish. On the other hand, having a Demodex overgrowth may lead to dry eye disease or make it worse.

Meibomian gland dysfunction (MGD) is also common among people with Demodex blepharitis. As the mite population goes up, the damage to these glands gets worse.

Complications of this condition

Without treatment, Demodex blepharitis can lead to long-term (chronic) eye problems. It can also affect how you feel from day to day. Possible complications include:

• Persistent eye redness/discoloration and irritation
• Eyelashes that grow toward your eye, rather than away from it
• Thinning or loss of eyelashes
• Eye infections that keep coming back
• Blurred vision
• New blood vessels forming in your eye that shouldn’t

Demodex blepharitis can also make it harder for you to wear contacts. You may even stop using them completely.

Aside from affecting your eyes, this condition can also impact your self-image and mental health. Changes to your eyelids or lashes may make you feel self-conscious. You may also find yourself worrying about your eyes all the time, especially if you can’t seem to find any relief.

How doctors diagnose this condition

Eye care specialists diagnose Demodex blepharitis with a slit lamp exam. This means you’ll sit in a chair while your provider uses a special microscope to look closely at your eyes. You’ll see some bright lights coming from different angles. Your provider will ask you to look downward or close your eyelids. This lets them see the base of your upper eyelashes, where signs of Demodex blepharitis typically appear.

The main sign providers look for are “collarettes.” You might also hear this called cylindrical dandruff, cuffs, crusting, sleeves or lash debris. It’s a waxy substance that builds up around the base of your eyelash follicles when you have a Demodex mite overgrowth. Collarettes are made of waste products from the mites.

Your provider can judge the severity of the condition by how many collarettes they see. Collarettes may appear on just a few lashes or nearly all of them. The more you have, the more severe the infestation. Your provider may take photos through the microscope so you can see the debris on your eyelashes. It’s otherwise hard to see on your own.

Other Demodex signs your provider will look for include:

• Eyelashes that grow in the wrong direction
• Redness, color changes or visible blood vessels along the edges of your eyelids
• Puffy eyelids

How is Demodex blepharitis treated?

Treatment for Demodex blepharitis involves getting rid of the excess mites and relieving symptoms. Lotilaner ophthalmic solution (Xdemvy™) is the first and only U.S. Food and Drug Administration (FDA)-approved treatment that targets the root cause of this condition — mite overgrowth. These are prescription eye drops that you use twice a day for six weeks. The drops can get the mite population under control and relieve symptoms for at least one year after you start using them.

Your eye care specialist may also recommend:

• Topical ointment: Your provider may prescribe an ointment that contains an antibiotic and a steroid. You apply it to your eyelids for about a week. This reduces eyelid swelling and helps get rid of bacteria that the mites leave behind.
• In-office procedures to remove lash debris: A provider uses a small, hand-held device to gently remove collarettes from your eyelashes. This can provide immediate relief for itching and discomfort.
• Eyelid scrubs: These are wipes or soaps you use at home to remove debris and oils the mites feed on. Follow your provider’s guidance on use. Some contain tea tree oil, which may irritate your skin.
• Warm compresses: Placing a compress over your eyes for about five minutes can loosen lash debris and help your meibomian glands work better. Choose a compress that you microwave or plug in. Washcloths you wring out in water don’t stay warm long enough.
• Lubricating eye drops: These soothe your eyes and may provide temporary symptom relief. But allow at least 10 minutes between these and any other drops you’re using, like Xdemvy. Don’t use drops that target “red eyes.” Those won’t help with this condition.

Before lotilaner ophthalmic solution was approved in 2023, providers used other treatments to manage Demodex blepharitis. But they now know that these treatments are often ineffective or have risks that outweigh any potential benefits. These older treatments included topical tea tree oil and oral antiparasitic drugs like ivermectin and metronidazole.

When should I see an eye care specialist?

Contact an optometrist or ophthalmologist if you have symptoms like itchy eyes, puffy eyelids or redness/discoloration anywhere along your lids. They’ll find the cause and help you get the right treatment.

After a Demodex diagnosis, contact your provider if:

• Your symptoms persist or get worse
• You have side effects from treatment
• You have questions about any part of your treatment plan, including how to use your eye drops

Your provider will schedule follow-up visits with you to see how treatment is going. 

What can I expect if I have Demodex blepharitis?

Demodex blepharitis is a chronic condition that won’t go away on its own. You need treatment to feel better and protect your eyes. Today, thanks to improvements in treatments, you can find relief within weeks. In the past, people often spent months or years dealing with symptoms that simply wouldn’t go away.

Many people see improvement in their symptoms as early as one to two weeks after starting lotilaner ophthalmic solution. But you need to continue using the drops for the full six weeks. That allows enough time to get rid of adult mites plus their eggs. If you stop using the drops too soon, the condition can come right back.

After you finish your course of drops, your eye doctor will examine your eyes. Many people are “cured” of Demodex blepharitis at this point. But if your provider still sees evidence of excessive mites, they’ll recommend further treatment.

Is there anything I can do to feel better?

The best thing you can do is follow the treatment plan from your eye doctor. If you’ve used eye drops only rarely in the past, using them twice a day for six weeks might feel like a lot. But you’ll get used to it faster than you may think. Soon, it’ll become another part of your routine, just like brushing your teeth. A treatment log or phone reminder can help you stay on track.

You’ll also want to take extra good care of your eyelids. Your provider may talk with you about eyelid hygiene. This doesn’t mean your lids were dirty or you didn’t take good care of them in the past. Instead, it means your skin is a place where Demodex mites can easily thrive. So, do whatever you can to keep them at bay.

Your provider may recommend:

• Using eyelid scrubs once or twice daily — on your lids, eyebrows, forehead and cheeks (these are all places where the mites can live)
• Removing makeup before bed
• Routinely washing your sheets, pillowcases and washcloths in hot water and drying them on high heat