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"For those of you who are not familiar with Demodex, it is a microscopic mite that is found living in the hair follicles or sebaceous glands of most humans and animals. Demodex may also infest follicles, with or without hair, anywhere on the body. Excessive number of Demodex mites may cause itching and certain kinds of skin disorders and is usually referred to as Demodicosis.
"Demodex mites are very common among humans and animals. Some have suggested that the mite can be found in over 90% of the adults. People who have oily skin are particularly prone to having the mites. Demodex is also called "Face Mite", since it is usually associated with blackheads, acne and other skin discorders. Sometimes when "blackheads" are squeezed out of the skin and examined under the microscope, Demodex mites are found. However, there is no apparent evidence that the mites cause blackheads.
"It has been reported that the mites live in human facial hair follicles, anterior end downward, and feed on epithelial cells or sebaceous secretions. During the daytime, mites remain within the follicle feeding. At night, they emerge onto the skin surface to mate. Eggs are laid in the lash follicles and the newly hatched larvae feed on the secretions.
"There is a close association between inflammation and Demodex. Some have suggested that inflammation and infection often result when a large number of mites infested a single hair follicle. Some research has shown that bacteria have been located on the bodies of Demodex folliculorum, a species of Demodex that is found in hair follicles, suggesting the potential of this mite as a transmitter of disease and cause of infection.
"The mite is commonly associated with inflammatory condition of the eyelids called Demodex blepharitis. Research has showed that as many as 25 mites can colonized one single eyelash. Excessive mites are usually associated with itchiness and discomfort of the eyelashes. Sometimes people lose their eyelashes as a result of Demodex blepharitis. Most Demodex blepharitis can be treated easily by doctors."
"Demodex species-induced pathologic changes have been implicated in dry eye conditions. When follicular plugging involves the meibomian gland (D brevis) or gland of Zeiss (D folliculorum or D brevis), reduction of the superficial lipid layer of the tear film occurs. The effect of D brevis on 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, cheek, or forehead."