Demodex folliculorum and Demodex brevis (hereafter referred to as ‘follicle mites’) are miniscule elongated mites that infest the skin of virtually every person. They are generally considered to be commensals (causing no disease), and live within sebaceous glands, most often on the face. These mites are nourished by sebum (skin oils); they neither bite nor feed on blood.
Generally, a few follicle mites are present in every square centimeter of skin. In a few cases, they may become far more abundant, and this may be coincidental with some kinds of facial dermatitis. Because the infestation is almost always without symptoms, treatment would rarely be justified. Interestingly, many persons become upset to learn that they serve as host to such trivial creatures. A few such individuals mistakenly believe that they must try to eradicate the mites and may pursue unwise and counterproductive efforts to attain that goal.