ABSTRACT
The essential elements of frontal traction alopecia are the presence of short broken hair, folliculitis lesions, and some small scar patches located on the frontotemporal edge. Some traumatic accidents can cause nonscarring alopecia, for which the diagnosis of cause can be difficult; it is, most often, ischemia caused by prolonged or repeated compression of part of the scalp. A variety of chemical and physical agents can cause permanent alopecia of the scalp. In general, any thermal, physical, or chemical injury sufficient to cause scalp necrosis can produce a permanent alopecia. Radiation injury may cause transient nonscarring alopecia. Higher doses produce permanent alopecia with scarring. Histological changes in anagen hair follicles can be noted as early as 4 days following radiation. Similar effects are noted with x-rays and electron beam radiation. Traction alopecia and trichotillomania are types of physical trauma that can lead to alopecia.
