File:Demodex Infestation - Skin (50196389113).jpg

Demodex mite is an obligate human ecto-parasite usually found in or near the pilo-sebaceous units of the face, head, and neck. They may also be found on the penis, mons veneris, buttocks, and in the ectopic sebaceous glands in the buccal mucosa. Demodex folliculorum and Demodex brevis are two species typically found on humans. Demodex infestation usually remains asymptomatic and may have a pathogenic role only when present in high densities and because of immune imbalance. These mites may be found in up to 10% of skin biopsies. Adult D. folliculorum mites are 0.3-0.4 mm in length and that of D. brevis are slightly shorter of 0.15-0.2 mm length. They are invisible to the naked eye. Under the microscope they have a semi-transparent, elongated body that consists of two fused segments. Eight short, segmented legs are attached to the first body segment. The body is covered with scales for anchoring itself in the hair follicle. The mite has pin-like mouth parts for eating skin cells, hormones, and oils (sebum) accumulating in the hair follicles. Ref. Indian J Dermatol. 2014 Jan-Feb; 59(1): 60–66. doi: 10.4103/0019-5154.123498