Traumatic alopecia results from the forceful extraction of hair secondary to mechanical friction, pressure, or physical trauma. Types of traumatic alopecia include self-inflicted trichotillomania; traction alopecia from tight braids, ponytails, or hair-straightening practices; prolonged pressure on the scalp of supine infants; and alopecia secondary to physical abuse. Traumatic alopecia associated with abuse can be challenging to distinguish from other forms of alopecia.

In traction alopecia, if the stimulus causing the traction is removed early, affected hair will recover. However, chronic long-term friction can cause permanent hair loss. Traction alopecia secondary to braids often results in hair loss on the scalp margin. It is more common in females and Black individuals due to hair-styling practices for tight braids or the use of chemical hair straighteners.

Trichotillomania is usually diagnosed in adolescents and preteens. It often starts during times of psychosocial stress such as hospitalization or familial discord. It is characterized by irregular patches of alopecia without evidence of scarring. Interestingly, the backgrounds in which trichotillomania develops and child abuse occurs are similar. Factors such as violence within the family, strained parental relationships, and a stressful environment such as illness or unemployment increase the risk of both occurring in children.

Pressure-induced alopecia refers to hair loss induced by localized pressure on the scalp due to prolonged immobilization. This results in a focal area of hair loss occurring several days to weeks after the initial trigger. The alopecia may be nonscarring (if diagnosed early) or scarring (if diagnosis is delayed). Any age group may be affected, including neonates and children.

In cases of localized hair loss in children, especially if a mechanical alopecia such as trichotillomania or traction alopecia is being considered, the possibility of child abuse should also be in the differential. Alopecia from abuse is classically associated with other signs of trauma such as scalp bruising and tenderness.