Demodex mites are microscopic arachnids that naturally reside on human skin, primarily within hair follicles and oil glands. Two main species are commonly found. While their presence is widespread among adults and usually causes no issues, these mites are a normal part of the body’s microbiome. However, when their numbers increase significantly, they can trigger symptoms, leading to a condition known as demodicosis.
Recognizing Potential Signs
An overgrowth of Demodex mites can manifest through several noticeable skin changes. Individuals might experience itching, redness, and a burning sensation on the skin. The skin’s texture may become rough or scaly, and some individuals might observe patchy or flaky areas.
Small raised bumps (papules) or pus-filled lesions (pustules) can also appear. When the area around the eyes is affected, a condition called blepharitis can develop, characterized by irritated, red, or dry eyelids, sticky eyelashes, and crustiness along the eyelid edges. This can also lead to eyelash loss. These symptoms are not exclusive to Demodex overpopulation and can indicate other dermatological conditions, underscoring the need for a professional assessment.
Initial Self-Observation
While Demodex mites are microscopic, individuals can observe indirect signs on their skin. This makes direct visualization impossible without magnification. Therefore, self-observation focuses on changes in skin texture or appearance. One might notice persistent redness or a rough, scaly feel to the skin, particularly on the face, scalp, or around the eyes.
Changes in skin texture, such as increased flakiness or the presence of small bumps around hair follicles, could be an indication. For the eyelids, signs like cylindrical dandruff, which are small, cylindrical particles at the base of the eyelashes, might be visible upon close inspection.
Professional Diagnostic Methods
For a definitive diagnosis of Demodex mite overpopulation, healthcare professionals utilize various microscopic examination techniques. The Standardized Skin Surface Biopsy (SSSB) is a common method, where a small amount of cyanoacrylate glue is applied to a glass slide, which is then pressed onto a 1 cm² area of the skin for about one minute. The slide is then gently removed, taking with it superficial skin layers and follicular contents, which are subsequently examined under a microscope to count the mites. A density exceeding five mites per square centimeter is often considered indicative of demodicosis.
Another technique is skin scraping, where a sterile scalpel blade is used to gently scrape the affected skin surface. The collected material is then transferred to a slide for direct microscopic examination. This method allows for the visualization and counting of mites. For areas like the eyelashes or eyebrows, hair plucking can be performed. Hairs are plucked from the affected area, placed in mineral oil on a slide, and then examined under a microscope for the presence of mites attached to the hair roots.
Tape stripping is another non-invasive method where adhesive tape is applied to the skin to collect samples of the superficial layer. The tape is then removed and analyzed microscopically for mites. Confocal laser scanning microscopy (CLSM) is also a non-invasive method that can detect mites in deeper parts of sebaceous glands.