Causes of hair loss induced by scalp infections.
Folliculitis is a term for inflammation of hair follicles. It looks like acne with little rings of inflammation surrounding the opening of a hair follicle. In the early stages of a folliculitis, the hair fiber may still be present, but as the folliculitis progresses the hair often falls out. There are non-infectious forms of folliculitis, such as those caused by oils and greases applied to the skin that clog up the hair follicles, but folliculitis is usually due to a bacterial infection. Nonprescription topical antibiotics such as bacitracin, mycitracin, or neomycin can be used to treat minor folliculitis
Piedra (trichomycosis nodularis) happens when the hair fibers are infected by a fungus. The visible indicator of a piedra infection is development of hard nodules on hair fibers. Indeed, “piedra” is Spanish for stone. Piedra infection may affect hairs of the scalp, body, and genital areas. Usually the infection is relatively benign. In parts of Malaysia, the nodules of black piedra are considered attractive and traditionally women encouraged its growth by sleeping with their hair buried in the soil. Treatment generally involves shaving off affected areas. Anti-fungals such as ketoconazole or terbinafine are also used.
Demodex is a little worm-like creature that likes to live on skin and in hair follicles. It feeds on dead skin and oils, so it particularly likes to live in hair follicles where there are lots of both.
Humans are born free of Demodex, but during childhood, through contact with others, the skin can become infected with it. For the most part, we never know they are there. They are benign, if repulsive, little creatures. The most common problem with Demodex is that they may cause irritation, particularly in the eyelashes. If you have itchy eyelashes, Demodex may be the problem.