Sex differences in age at onset and presentation of trichotillomania and trichobezoar: A 120-year systematic review of cases

Trichotillomania (hair-pulling disorder) has high female preponderance. It has been suggested that onset in early childhood represents a distinct developmental subtype that is characterized by higher prevalence of males compared to later onset cases. However, the empirical literature is scarce. We conducted a systematic review of case reports to examine the distribution of age at onset/presentation in males and females with trichotillomania or trichobezoar (a mass of hair in the gastrointestinal tract resulting from ingesting hair).