Trichotillomania— compulsive hair pulling. Hair loss due to trichotillomania is typically patchy, as compulsive hair pullers tend to concentrate the pulling in selected areas. Hair loss due to this cause cannot be treated effectively until the psychological or emotional reasons for trichotillomania are effectively addressed.
Alopecia areata— a possibly autoimmune disorder that causes patchy hair loss that can range from diffuse thinning to extensive areas of baldness with “islands” of retained hair. Medical examination is necessary to establish a diagnosis.
Triangular alopecia— loss of hair in the temporal areas that sometimes begins in childhood. Hair loss may be complete, or a few fine, thin-diameter hairs may remain. The cause of triangular alopecia is not known, but the condition can be treated medically or surgically.
Scarring alopecia— hair loss due to scarring of the scalp area. Scarring alopecia typically involves the top of the scalp and occurs predominantly in women. The condition frequently occurs in African-American women and is believed to be associated with persistent tight braiding or “corn-rowing” of scalp hair. A form of scarring alopecia also may occur in post-menopausal women, associated with inflammation of hair follicles and subsequent scarring.
Telogen effluvium— a common type of hair loss caused when a large percentage of scalp hairs are shifted into “shedding” phase. The causes of telogen effluvium may be hormonal, nutritional, drug-associated, or stress-associated. Loose-anagen syndrome—a condition occurring primarily in fair-haired persons in which scalp hair sits loosely in hair follicles and is easily extracted by combing or pulling. The condition may appear in childhood, and may improve as the person ages.