Diagnosing Ocular Demodicosis

GENERAL INFORMATION

Demodex is a small parasite that inhabits human skin. It causes a disease called demodicosis (or demodicidosis).

Demodex is a mite, and although it measures only about a quarter of a millimeter, it can cover a distance of more than a centimeter and a half in a single day. It lives for about 18-25 days, laying about 20 eggs. The parasite passes through several stages of development, and all its developmental forms feed on dead cells of the skin epithelium, plasma and sebum.

Demodex mites live in the sebaceous glands, especially around the face and ears, and in the hair follicles. As for the eye, they choose eyelashes, where they plunge their mouth into the hair follicle. If the number of parasites is large and there is not enough space in the follicle, the hair is displaced or it falls out.

Symptoms of demodicosis include eyebrow and eyelash loss, itching, redness and irritation of the eyelid skin, sometimes combined with chronic inflammation.

Not all people who have demodex develop demodicosis. Demodex can also reside on the skin without causing inflammatory symptoms or other ocular problems. It all depends on individual susceptibility to the disease and local immunity.

Important! The presence of demodex on the skin is also very often the cause of dermatological problems in the form of facial redness, blemishes or acne.

PRACTICAL INFORMATION

Testing for ocular demodicosis is especially recommended for patients who struggle with eyelash loss, red and irritated eyelid margins, inflamed eyelids, and recurrent chalazions. It may also be needed by those complaining about dermatological problems in the form of facial redness, blemishes or acne.

Testing for ocular demodicosis involves a microscopic evaluation of an eyelash or epidermis sample taken from the patient. Demodex can be seen well under magnification, the stages of their development can be differentiated, and the size of infestation assessed.