If you’ve ever woken up with red, itchy, or crusty eyes, you’re not alone. You may be among the estimated 15–20 million Americans affected by Demodex blepharitis, a condition that’s often underdiagnosed but easily treatable once identified.
In a recent episode of The Dry Eye Podcast, Dr. Elizabeth Yeu, Chief Medical Officer of Tarsus Pharmaceuticals, broke down what this condition is, why it’s so commonly mistaken for allergies or dry eye, and how targeted treatment can make a major difference.
What Is Demodex Blepharitis?
Demodex blepharitis is caused by microscopic mites called Demodex that live in the hair follicles and oil glands of our eyelids. While the idea might sound unsettling, most of us naturally have these mites. The issue arises when they multiply excessively—particularly in the lash follicles—leading to inflammation, itching, redness, and discomfort.
“It’s not dry eye disease per se, but it shares many overlapping symptoms,” Dr. Yeu explains. “And one of the biggest clues is crusting at the base of the eyelashes—especially when you wake up in the morning.”
These telltale signs are known as collarettes, and they’re visible under magnification. “If I see even one or two crusts, that’s enough for me to diagnose Demodex blepharitis,” says Dr. Yeu.
Common Symptoms to Watch For:
- Red or itchy eyelids, especially upon waking
- A gritty or tired sensation in the eyes
- Crusting or flakes around the eyelashes
- Thinning or loss of eyelashes
- Fluctuating vision throughout the day
Interestingly, the way people scratch their eyes can also offer clues. Dr. Yeu notes that Demodex-related itching often happens along the lash line, rather than in the corners of the eyes (which is more typical for allergies).
Why It’s Often Missed
Because Demodex blepharitis symptoms mimic those of allergies or chronic dry eye, it can go undetected or misdiagnosed for years. It also shares a strong connection with ocular rosacea, another underdiagnosed condition that involves inflammation and redness.
“Many people just assume they have bad allergies or are using the wrong mascara,” says Dr. Yeu. “But this is something deeper—and treatable.”
The Good News: It’s Treatable
Until recently, options for treating Demodex were mostly homeopathic or over-the-counter wipes and warm compresses. These methods often help with symptoms but don’t eliminate the root cause—the mites themselves.
“After the six-week course with Xdemvy, most of my patients don’t require any maintenance treatment,” says Dr. Yeu. “We’ve seen that only about 20–40% may see some recurrence after six to nine months. But it’s incredibly manageable.”
Pro Tips from Dr. Yeu
Throw out old makeup: If you’ve been diagnosed, replace mascara and eyeliners to avoid reinfection.
Be alert to vision changes: Fluctuating vision can be an early warning sign.
Don’t overdo hygiene: Washing your face more won’t help. These mites thrive in oil glands and are not related to personal hygiene.
Get a professional exam: Even minor symptoms can be signs of a larger issue. Early diagnosis is key.
If you’re using artificial tears multiple times a day, or waking up with red, irritated eyes, it might be time to look deeper. Demodex blepharitis is more common than most people realize—but with the right treatment, it doesn’t have to be a lifelong nuisance.
“You only get one pair of eyes,” Dr. Yeu says. “And this is one condition that we can actually take care of—completely.”