November 7, 2012 | Comments Off
Before Dr. Tseng and his colleagues tried the tea tree oil scrub, “there was no treatment that could kill the Demodex. You can clean the lashes and use the shampoo, but no agent could truly kill it.
Tea tree oil does. That’s very major. If doctors can’t kill an organism, they don’t really know if the treatment is effective,” he said. To diagnose the problem, Steven Safran, M.D., said initially the diagnosis requires examining the lashes with a microscope to know what to identify. “[The mites] sit head down, tails up, with the tails aligned along the lash at the root,” Dr. Safran said. “Often there is columnar dandruff or cylindrical cuffing. If you rock the lash from side to side and pull, you’ll see the tails spread out along the base of the lash like little bristles. When you pull the lash, often the mites stay in the follicle, and you have to dip the lash back down into the follicle to get some of the mites onto the lash for evaluation.”
He said most patients are disbelieving at first, “until you show them the mites moving under the microscope. When they see that, they’re ready to listen.”
Dr. Safran stressed that epilating the lashes alone is not sufficient. “With many of the first patients I examined, I missed the mites because I was just pulling lashes and looking, which was quite ineffective in many patients,” he said.
Call it “The Case of the Mighty Mite.”
For decades, refractory blepharitis has confounded ophthalmologists.
Some patients respond to lid scrubs; some do not. Some present within days of a spouse’s presentation. Some present concurrently with pterygia. Blepharitis seems more pronounced in some than in others. The cause of blepharitis may be as simple as the Demodex mite. A recent journal article noted a variety of pathologic features together with conjunctival inflammation can be found in patients with Demodex infestation of the eyelids.
These same kinds of pathologies are commonly found in ocular rosacea, said Scheffer C.G. Tseng, M.D., director of the Ocular Surface Center and medical director, Ocular Surface Research & Education Foundation at TissueTech, Miami. “When conventional treatments for rosacea fail, tea tree oil lid scrubs seem to eradicate the mites,” Dr. Tseng said. “In any type of ocular inflammation where the condition is refractory, doctors need to consider Demodex as a causative agent,” he said. “For instance, recurrent pterygia may be the result of an inflammatory disease, and it may be Demodex that hasn’t been well treated. That would explain the pterygia’s recurrence.”
November 5, 2012 | Comments Off
To compare the in vitro killing effect of different agents on Demodex and to report the in vivo killing effect of tea tree oil (TTO) on ocular Demodex.
Survival time of Demodex was measured under the microscope. Sampling and counting of Demodex was performed by a modified method.
Demodex folliculorum survived for more than 150 minutes in 10% povidone-iodine, 75% alcohol, 50% baby shampoo, and 4% pilocarpine.
However, the survival time was significantly shortened to within 15 minutes in 100% alcohol, 100% TTO, 100% caraway oil, or 100% dill weed oil. TTO’s in vitro killing effect was dose dependent. Lid scrub with 50% TTO, but not with 50% baby shampoo, can further stimulate Demodex to move out to the skin. The Demodex count did not reach zero in any of the seven patients receiving daily lid scrub with baby shampoo for 40-350 days. In contrast, the Demodex count dropped to zero in seven of nine patients receiving TTO scrub in 4 weeks without recurrence.
Demodex is resistant to a wide range of antiseptic solutions. Weekly lid scrub with 50% TTO and daily lid scrub with tea tree shampoo is effective in eradicating ocular Demodex.
In vitro live and dead status of Demodex. The same Demodex was photographed before (A, C, and E) and 5 minutes later (B, D, and F). The Demodex was judged to be “live” by vivid movement of the body (A, B) or legs (C, D). In contrast, the Demodex was judged to be “dead” by the lack of movement (E, F). Furthermore, all eight legs of the dead mite were stretched apart (E, F) distinctively different from the live one (C, D).
November 5, 2012 | Comments Off
A new review carried out by the National University of Ireland concludes that rosacea may be triggered by bacteria that live within tiny mites that reside in the skin.
The mite species Demodex folliculorum is worm-like in shape and usually lives harmlessly inside the pilosebaceous unit which surrounds hair follicles of the face. They are normal inhabitants of the face and increase in number with age and skin damage — for example, following exposure to sunlight. The numbers of Demodex mites living in the skin of rosacea patients is higher than in normal individuals, which has previously suggested a possible role for the mites in initiating the condition.
More recently, the bacterium Bacillus oleronius was isolated from inside a Demodex mite and was found to produce molecules provoking an immune reaction in rosacea patients. Other studies have shown patients with varying types of rosacea react to the molecules produced by this bacterium — exposing it as a likely trigger for the condition. What’s more, this bacterium is sensitive to the antibiotics used to treat rosacea.
From Here :
Accumulation of waste material of the follicle mite may occur in affected follicles or sebaceous glands. Electron micrographs of the mite surface and feces show bacterial, viral, and rickettsial elements. Specific reports have revealed that both species pierce epithelial cells and consume cytoplasm. Only D brevis has been observed with channels burrowed to the germinal epithelium in the sebaceous glands.
These mites also serve as vectors of infective elements and interrupt tissue integrity.
Demodex species-induced pathologic changes have been implicated in dry eye conditions. When follicular plugging involves the meibomian gland (D brevis) or the gland of Zeis (D folliculorum or D brevis), reduction of the superficial lipid layer of the tear film occurs. The effect of D brevis on the meibomian structure has been implicated in chalazion formation. Chalazia are granulomatous inflammation of the meibomian glands, made of an organized core of epithelioid cells and histocytes surrounded by fibroblasts, lymphocytes, and plasma cells. These defense cells encircle particles too large for normal macrophages to engulf. D brevis has been observed in the center of these meibomian granulomas. Lid infestation by the Demodex species may or may not accompany dermatologic changes of the nose, the cheek, or the forehead.