Body-focused repetitive behaviour disorders

Description

Body focused repetitive behaviour disorders are characterised by recurrent and habitual actions directed at the integument (e.g. hair-pulling, skin-picking, lip-biting), typically accompanied by unsuccessful attempts to decrease or stop the behaviour involved, and which lead to dermatological sequelae (e.g., hair loss, skin lesions, lip abrasions). The behaviour may occur in brief episodes scattered throughout the day or in less frequent but more sustained periods. The symptoms result in significant distress or significant impairment in personal, family, social, educational, occupational or other important areas of functioning. [1]

Diagnostic requirements

WHO clinical descriptions and diagnostic requirements [1,2].

Subcategories

• 6B25.0 Trichotillomania

  Trichotillomania is characterised by recurrent pulling of one’s own hair leading to significant hair loss, accompanied by unsuccessful attempts to decrease or stop the behaviour. Hair pulling may occur from any region of the body in which hair grows but the most common sites are the scalp, eyebrows, and eyelids. Hair pulling may occur in brief episodes scattered throughout the day or in less frequent but more sustained periods. The symptoms result in significant distress or significant impairment in personal, family, social, educational, occupational or other important areas of functioning. [1]

  Essential (Required) Features:

  • Recurrent pulling of one’s hair.
  • Unsuccessful attempts to stop or decrease hair pulling.
  • Significant hair loss results from pulling behaviour.
  • The symptoms result in significant distress or significant impairment in personal, family, social, educational, occupational or other important areas of functioning.

  Additional Clinical Features:

  • Hair pulling may occur from any region of the body where hair grows. However, the most common sites are the scalp, eyebrows, and eyelids. Less frequently reported sites are axillary, facial, pubic, and peri-rectal regions. Patterns of hair loss are variable with some areas of complete alopecia and others with thinning hair density.
  • Individuals with Trichotillomania (Hair Pulling Disorder) may pull hair in a widely distributed pattern (i.e., pulling single hairs from all over a site) such that hair loss may not be clearly visible. Alternately, individuals may attempt to conceal or camouflage hair loss (e.g., by using makeup, scarves, or wigs).
  • The diagnosis of Trichotillomania is typically made based on direct observation or physical examination of the hair loss. If this is not possible (e.g., because of religious proscriptions), then it may be difficult to make a judgment about the extent of hair loss. In such cases corroborative evidence may be required from a knowledgeable informant or physician who has conducted a physical examination of the individual.
  • Hair pulling may occur in brief episodes scattered throughout the day or in less frequent but more sustained periods that can continue for hours. Hair pulling may endure for months or years before coming to clinical attention.
  • Trichotillomania often presents with rituals surrounding hair such as visually or tactilely examining the hair or orally manipulating the hair after it has been pulled. Individuals who commonly swallow or eat the hair that has been pulled (trichophagia) can experience serious and even life-threatening gastrointestinal symptoms, depending on the volume of hair consumed.
  • Focused hair pulling often increases during periods of increased psychological distress.
  • Hair pulling behaviour is associated with a variety of reported effects including regulation of affect and arousal, tension-reduction, and promotion of pleasure, which presumably reinforce these behaviours. However, in the aftermath of hair pulling, many individuals report a variety of negative affective states, such as a sense of loss of control or shame. Individuals with Trichotillomania report varying degrees of awareness of their hair pulling behaviour.
  • Excoriation Disorder is a common co-occurring condition in individuals with Trichotillomania. Trichotillomania also commonly co-occurs with depressive and anxiety symptoms, Obsessive-Compulsive Disorder, and other body-focused repetitive behaviours (e.g., nail biting).

  Boundary with Normality (Threshold):

  • Occasional pulling of a grey or out-of-place hair is normal and done by most people at some time in their lives. Many individuals also twist and play with their hair, whereas others may bite or tear rather than pull their hair; these behaviours do not qualify for a diagnosis of Trichotillomania (Hair Pulling Disorder). Trichotillomania involves recurrent hair pulling and is associated with significant distress or impairment, which are not present in occasional, normal pulling.

  Course Features:

  • Trichotillomania (Hair Pulling Disorder) is generally considered a chronic condition; however, for some individuals, symptoms may wax and wane for weeks, months, or years at a time without intervention. Rates of remission decrease with increasing time since symptom onset.
  • Patterns of hair pulling behaviour vary greatly and individual sites of hair pulling may change over time.

  Developmental Presentations:

  • Onset of Trichotillomania (Hair Pulling Disorder) is bimodal, with a peak during early childhood and one during early adolescence.
  • Hair-pulling behaviour in infancy (i.e., before age of 2 years) is relatively common with most individuals ceasing to engage in the behaviour by early childhood. However, many adults reporting a chronic history of Trichotillomania describe early childhood onset. It is therefore unknown whether onset in early childhood (compared to adolescent-onset) presents as a distinct subtype of the disorder or what factors may contribute to persistence.
  • Onset is most common in early adolescence, coinciding with puberty. Adolescent onset is associated with greater chronicity and impairment. Prevalence rates among adolescents are similar to adults (approximately 1 to 2% of the general population).
  • Children and youth engage more frequently in automatic hair pulling, that is, they engage in the behaviour outside of awareness. Focused, intentional hair pulling is often preceded by intense urges and followed by relief is more common among adolescents and adults.
  • The negative impact of hair pulling appears to become more severe across developmental periods. Children under age 10 appear to experience less academic impact than older children and adolescents, who tend to report more difficulties in school attendance and academic performance as a result of hair pulling.
  • Similar to adults, children and adolescents with Trichotillomania appear to have high rates of co-occurring mental health disorders including Generalized Anxiety Disorder, Obsessive-Compulsive Disorder, Excoriation (skin-picking) Disorder, other Body-Focused Repetitive Behaviour Disorders, and Depressive Disorders. Children and adolescents may also be more likely to present with co-occurring Attention Deficit Hyperactivity Disorder.

  Sex- and/or Gender-Related Features:

  • Prevalence rates appear to be equal among girls and boys in childhood, though female adolescents and adults are more commonly diagnosed.
  • Although there is no evidence for gender differences in course and symptom presentation, men are more likely to experience a co-occurring Anxiety or Fear-Related Disorder or Obsessive-Compulsive Disorder.
  • Focused hair pulling in women often increases during puberty as well as at other times of hormonal fluctuations during adulthood (i.e., menstruation, perimenopause).

  Boundaries with Other Disorders and Conditions (Differential Diagnosis):

  • Boundary with other Obsessive-Compulsive or Related Disorders: Repetitive behaviours observed in Trichotillomania (Hair Pulling Disorder) occur in other Obsessive-Compulsive or Related Disorders but these are typically related to specific foci of apprehension and are associated with distinct intent for each diagnostic entity. Individuals diagnosed with Obsessive-Compulsive Disorder may engage in hair pulling behaviour (e.g., as a symmetry ritual meant to ‘balance’ their hair). Furthermore, individuals with Obsessive-Compulsive Disorder, often exhibit other symmetry rituals alongside identifiable obsessions and compulsions unrelated to hair pulling. Nonetheless, co-occurrence with Obsessive-Compulsive Disorder is common and if both disorders are present both may be coded. Body Dysmorphic Disorder may be associated with removal of body hair that the individual perceives as ugly or as appearing abnormal.
  • Boundary with Stereotyped Movement Disorder: A stereotyped movement is a repetitive, seemingly driven nonfunctional motor behaviour (e.g., head banging, body rocking, self-biting). These behaviours rarely include hair pulling behaviour but if they do, the behaviour tends to be composed of coordinated movements that are patterned and predictable. Furthermore, stereotyped movements are more likely to present very early in life (i.e., before 2 years of age), whereas Trichotillomania typically has an onset in early adolescence.
  • Boundary with Schizophrenia or Other Primary Psychotic Disorders: Individuals with Schizophrenia or Other Primary Psychotic Disorder may remove hair in response to a delusion or hallucination. An additional diagnosis of Trichotillomania should not be assigned in such cases.
  • Boundary with medical conditions classified elsewhere and Disorders Due to Substance Use: The symptoms are not a manifestation of another medical condition (e.g., inflammation of the hair follicles). Skin biopsy or dermoscopy are able to differentiate individuals with trichotillomania from those with dermatological disorders. Although hair pulling behaviour may be exacerbated by certain substances (e.g., amphetamine), there is no evidence that substances can be the primary cause of recurrent hair pulling.
• 6B25.1 Excoriation disorder

  Excoriation disorder is characterised by recurrent picking of one’s own skin leading to skin lesions, accompanied by unsuccessful attempts to decrease or stop the behaviour. The most commonly picked sites are the face, arms and hands, but many individuals pick from multiple body sites. Skin picking may occur in brief episodes scattered throughout the day or in less frequent but more sustained periods. The symptoms result in significant distress or significant impairment in personal, family, social, educational, occupational or other important areas of functioning. [1]

  Essential (Required) Features:

  • Recurrent picking of one’s skin.
  • Unsuccessful attempts to stop or decrease skin picking.
  • Significant skin lesions resulting from picking behaviour.
  • The symptoms result in significant distress or significant impairment in personal, family, social, educational, occupational or other important areas of functioning.

  Additional Clinical Features:

  • Trichotillomania is a common comorbid condition in individuals with Excoriation Disorder. Furthermore, Excoriation (Skin Picking) Disorder commonly co-occurs with depressive and anxiety symptoms, Obsessive-Compulsive Disorder, and other body-focused repetitive behaviours (e.g., nail biting).
  • The most commonly picked sites are the face, arms and hands, but many individuals pick from multiple body sites. Individuals may pick at healthy skin, at minor skin irregularities, at lesions such as pimples or calluses, or at scabs from previous picking. Most individuals pick with their fingernails, although a substantial minority use tweezers, knives, or other objects. The Essential Features emphasize that skin picking must lead to skin lesions. However, individuals with this disorder often attempt to conceal or camouflage evidence of skin picking (e.g., using make-up or clothing). Therefore, careful assessment including information from collateral sources may be required to ascertain the presence of Excoriation Disorder symptomatology.
  • Individuals with Excoriation Disorder often spend significant amounts of time on their behaviour, sometimes several hours each day. Skin picking may endure for months or years before coming to clinical attention.
  • Excoriation Disorder often presents with rituals surrounding the skin such as visually or tactilely examining the skin, orally manipulating, or eating the skin or scab after it has been picked.
  • Skin picking behaviour is associated with a variety of reported effects including regulation of affect and arousal, tension-reduction, and promotion of pleasure, which presumably reinforce these behaviours. However, in the aftermath of skin picking, many individuals report a variety of negative affective states, such as a sense of loss of control or shame. Individuals with Excoriation Disorder report varying degrees of awareness of their skin picking behaviour.

  Boundary with Normality (Threshold):

  • Occasional picking of one’s skin (e.g., scabs, cuticles or acne) is normal and done by most people at some time in their lives. Some individuals bite their cuticles or surrounding skin; these behaviours do not qualify for a diagnosis of Excoriation (Skin Picking) Disorder. Excoriation Disorder involves recurrent picking and is associated with significant distress or impairment, which are not present in occasional, normal skin picking.

  Course Features:

  • Onset can occur at any age but most often coincides with onset or shortly after onset of puberty.
  • The onset of Excoriation (Skin Picking) Disorder commonly occurs in association with dermatological condition, but the skin picking persists after the dermatological condition resolves.
  • For some individuals an urge to pick at their skin may be preceded by emotional triggers such as increasing feelings of anxiety and tension or boredom. Others may pick at their skin in response to tactile sensitivity (i.e., skin irregularities) or bothersome skin sensations. In such cases, skin picking often results in an alleviation of tension, relief or a sense of gratification.
  • Excoriation Disorder is generally considered a chronic condition. Some individuals may experience a waxing and waning of symptoms over weeks, months, or years at a time.

  Developmental Presentations:

  • Excoriation (Skin Picking) Disorder most often has its onset during adolescence typically corresponding to puberty. However, the emergence of symptoms can occur across the lifespan.
  • Childhood-onset Excoriation Disorder is more prevalent among females.
  • Automatic skin picking, which tends to occur unintentionally, outside of awareness, appears more frequently among individuals with childhood-onset Excoriation Disorder. Skin picking then appears to shift in adolescence and adulthood, as picking becomes focused. This picking appears to be generally intentional, connected to intense urges to pick, and often results in a sense of relief.

  Sex- and/or Gender-Related Features:

  • Prevalence rates for Excoriation Disorder are significantly higher for women.
  • Men have an earlier age of onset for the disorder.

  Boundaries with Other Disorders and Conditions (Differential Diagnosis):

  • Boundary with other Obsessive-Compulsive or Related Disorders: Repetitive behaviours observed in Excoriation Disorder occur in other Obsessive-Compulsive or Related Disorders but these are typically related to specific foci of apprehension and are associated with distinct intent for each diagnostic entity. Individuals diagnosed with Obsessive-Compulsive Disorder may engage in skin picking behaviour (e.g., when they experience contamination obsessions that are associated with behaviours intended to pick the skin to remove contamination). Obsessions do not precede skin picking in Excoriation Disorder, and individuals with Obsessive-Compulsive Disorder often exhibit other compulsions that are unrelated to skin picking. Nonetheless, co-occurrence with Obsessive-Compulsive Disorder is common and both disorders may be diagnosed if warranted. Body Dysmorphic Disorder may be associated with picking as a means of improving the individual’s appearance by ‘removing’ acne or other perceived blemishes of the skin that the individual believes are ugly or that appear abnormal. Individuals with Excoriation Disorder do not pick skin with the sole purpose of correcting a perceived defect in appearance.
  • Boundary with Stereotyped Movement Disorder: A stereotyped movement is a repetitive, seemingly driven nonfunctional motor behaviour (e.g., head banging, body rocking, self-biting). These behaviours rarely include skin picking behaviour but if they do, the behaviour tends to be composed of coordinated movements that are patterned and predictable. Furthermore, stereotyped movements are more likely to present very early in life (i.e., before 2 years of age), whereas Excoriation Disorder typically has a later onset.
  • Boundary with Schizophrenia or Other Primary Psychotic Disorders: Individuals with Schizophrenia or Other primary psychotic disorders may pick at their skin in response to a delusion or hallucination. Individuals with Excoriation Disorder do not report skin picking secondary to delusions or hallucinations.
  • Boundary with Prader-Willi Syndrome: Individuals with Prader-Willi Syndrome may have early onset of skin picking more consistent with a Stereotyped Movement Disorder. Prader-Willi Syndrome is usually associated with a constellation of other symptoms such as Mild to Moderate Disorder of Intellectual Development, neonatal and infantile hypotonia, feeding problems and poor weight gain in infancy followed by hyperphagia and morbid obesity in childhood.
  • Boundary with medical conditions classified elsewhere and Disorders Due to Substance Use: The symptoms are not a manifestation of another medical condition (e.g., scabies). However, skin picking may emerge following or be worsened by the presence of another condition (e.g., acne) and a diagnosis of Excoriation Disorder may be applied in this circumstance if diagnostic requirements are met. Skin picking may also result from the use or misuse of stimulants (e.g., cocaine, methamphetamine, prescription stimulants), but Excoriation Disorder should not be diagnosed if the skin picking occurs exclusively in this context.
  • Boundary with self-injurious and self-mutilating behaviours: Unlike self-injurious and self-mutilating behaviours, skin picking behaviours characteristic of Excoriation Disorder are not performed with the express purpose of self-injury though such injury may occur as a result.

References

1. World Health Organization. International Classification of Diseases, 11th Revision, for Mortality and Morbidity Statistics (ICD-11 MMS), 2026-01 release. World Health Organization; 2026.
2. World Health Organization. Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders (CDDR). World Health Organization; 2024.

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