Body-focused repetitive behaviour disorders

ICD-10F63.3	Trichotillomania
DSM-5-TRF63.3 / L98.1	Trichotillomania (Hair-Pulling Disorder) / Excoriation (Skin-Picking) Disorder

1. Definition and nosology

Body-focused repetitive behaviour disorders (ICD-11: 6B25) — a group of disorders characterized by the patient’s repetitive interference with their own body (hair, skin, nails). Main subtypes:

• 6B25.0 Trichotillomania (hair-pulling disorder);
• 6B25.1 — Excoriation / Dermatillomania (skin-picking disorder);
• 6B25.Y Other specified (nail biting — onychophagia, lip biting, cheek biting).

DSM-5-TR — Trichotillomania (F63.3) and Excoriation (L98.1) coded separately, but within the OCD spectrum category.

2. History

• Hallopeau F.H. (1889) — term “trichotillomania”.
• DSM-III-R (1987) — Trichotillomania as an impulse control disorder.
• DSM-5 (2013) — moved to the OCD spectrum category; excoriation added as a separate diagnosis.
• ICD-11 (2019) — as a joint category (6B25 umbrella).

3. Epidemiology

• Lifetime prevalence of trichotillomania: 0.5–2%; in clinical samples, females ≈ 10:1.
• Excoriation: 1.4–5.4%; higher in females.
• Onset: adolescence (10–13 years).
• Comorbidity: MDD, anxiety, OCD, BDD, ADHD.

4. Etiology and pathogenesis

• Heritability 30–40%; family history is common.
• Genetic — SLITRK1 (in humans); SAPAP3 — hypergrooming phenotype in mice.
• Neurobiological — OCD-like cortico-striato-thalamo-cortical dysregulation, but with a different profile.
• Behavioral mechanisms: stress response, ‘automatic’ (unconscious) and ‘focused’ (purposeful, with intense attention) subtypes.

5. Clinical features

Trichotillomania (6B25.0)

• Hair pulling — usually from head, eyebrows, eyelashes; sometimes from other body parts.
• Visible hair loss.
• “Pre-pulling tension” or “post-pulling relief” — may not be present in all patients.
• Trichophagia (eating of pulled hair) — in 10–20% of patients; ‘trichobezoar’ — gastrointestinal obstruction may require surgery.

Excoriation / Dermatillomania (6B25.1)

• Skin picking — face, arm, damaged skin areas (“acne”, insect bite site).
• Injury, crust, scars.
• Infection, scarring, cosmetic outcomes.

General characteristics

• The patient makes repeated unsuccessful attempts to stop the behavior.
• Social isolation due to shame (wearing a wig, covering mouth/hands).

6. Diagnosis

6.1 Unified diagnostic criteria

A. Hair pulling (in trichotillomania) or skin picking (in excoriation) — visible hair loss or skin damage.

B. The patient makes repeated attempts to stop or reduce the behavior.

C. Behavior causes clinically significant distress or functional impairment.

D. Exclusion of a medical condition (alopecia areata, dermatological illness) or another mental disorder (e.g., appearance-motivated behavior in BDD; delusional content in a psychotic episode; substance-induced).

6.2 Differences between sources

• DSM-5-TR — Trichotillomania (F63.3) and Excoriation (L98.1) separate.
• ICD-11 — under the common 6B25 umbrella; subspecifiers.

6.3 Diagnostic algorithm

1. Clinical interview (patient often does not speak openly due to shame).
2. Dermatological examination — exclusion of other causes of hair loss and skin lesions (alopecia areata, tinea capitis, eczema).
3. Scale — Massachusetts General Hospital Hairpulling Scale (MGH-HPS), Skin Picking Scale.
4. Comorbidity screening.
5. Trichophagia screening — if gastrointestinal symptoms present.

6.4 Differential diagnosis (Table 1)

7. Examination and assessment

• MGH-HPS (trichotillomania), Skin Picking Scale-Revised.
• Dermatological examination.
• Abdominal ultrasound in case of trichophagia.

8. Treatment

1. Habit Reversal Training (HRT) first-line — awareness training, competing response (e.g., fist clenching), motivation, social support, generalization. Evidence: Bloch M.H. et al. Biol Psychiatry 2007 meta-analysis.
2. ACT (Acceptance and Commitment Therapy) — targets emotional component.
3. Comprehensive Behavioral Treatment (ComB, Mansueto) — HRT + multimodal behavioral intervention.
4. N-acetylcysteine (NAC) — evidence base developing; Grant J.E. et al. Arch Gen Psychiatry 2009 RCT — efficacy in trichotillomania.
5. SSRI — evidence base is limited; SSRIs effective in OCD give a weak response in trichotillomania; clomipramine is relatively superior.
6. Atypical antipsychotic adjunct — in refractory cases.
7. Dermatological care — management of injuries and infections.

8.1 Treatment methods

1. Habit Reversal Training (HRT — Habit Reversal Training) — Azrin (Azrin N.H.), Nunn (Nunn R.G.) — Five core components — awareness training, competing response, motivation, social support, generalization. Gold standard in body-focused repetitive behaviors.
2. Comprehensive Behavioral Treatment (ComB) — Mansueto (Mansueto C.S.) — SCAMP model — individualized approach based on Sensory, Cognitive, Affective, Motor, Place modalities.
3. Acceptance and Commitment Therapy (ACT) — Focus on the emotional component; Woods D.W. et al. Behav Res Ther 2006 RCT.
4. NAC — N-acetylcysteine — Glutamatergic modulator; 1200–2400 mg/day; Grant J.E. Arch Gen Psychiatry 2009.
5. Massachusetts General Hospital Hairpulling Scale (MGH-HPS) — 7 items; frequency, intensity.

8.2 Differences between sources

• Bloch M.H. Biol Psychiatry 2007 meta-analysis — HRT most evidence-based for trichotillomania.
• Grant J.E. Arch Gen Psychiatry 2009 — NAC 1200–2400 mg/day efficacy.

9. Prognosis

• Chronic course, “waxing and waning”.
• Significant improvement with HRT; treatment of comorbidity is essential.

10. Myths and misconceptions

Myth 1: “Hair pulling and skin picking are ‘bad habits’, not serious disorders”

Evidence: Clinical impairment; risks of functional impairment, social isolation, infection, and trichobezoar (surgical).

Myth 2: “The patient can stop voluntarily”

Evidence: The patient repeatedly tries and fails — this is the main symptom of the disorder; HRT or pharmacotherapy is required.

Myth 3: “SSRIs are effective for trichotillomania (like OCD)”

Evidence: Response to SSRIs is weaker than in OCD; HRT is first-line; NAC adjunct; clomipramine relatively superior over SSRIs.

Myth 4: “Hiding hair (wig, makeup) is the solution”

Evidence: Cosmetic camouflage is short-term; primary behavioral intervention required.

Myth 5: “Only hypnosis or deep psychoanalytic therapy resolves the underlying behavioral cause”

Evidence: the evidence base is limited; HRT-based behavioral approaches are superior.

Myth 6: “Skin picking is a response to ‘acne’ or a cosmetic problem”

Evidence: Clinical impairment — patient cannot prevent behavior, causes scarring and infection of the skin; clinical intervention required.

11. Sources

1. WHO. ICD-11. 6B25 Body-focused repetitive behaviour disorders. 2024.
2. APA. DSM-5-TR. 2022.
3. Bloch M.H. et al. Systematic review: pharmacological and behavioral treatment for trichotillomania. Biol Psychiatry 2007;62(8):839–846.
4. Grant J.E. et al. N-acetylcysteine, a glutamate modulator, in the treatment of trichotillomania: a double-blind, placebo-controlled study. Arch Gen Psychiatry 2009;66(7):756–763.
5. Woods D.W., Wetterneck C.T., Flessner C.A. A controlled evaluation of acceptance and commitment therapy plus habit reversal for trichotillomania. Behav Res Ther 2006;44(5):639–656.
6. Mansueto C.S., Goldfinger Golomb R., Thomas A.M., Stemberger R.M.T. A comprehensive model for behavioral treatment of trichotillomania. Cogn Behav Pract 1999;6(1):23–43.
7. Azrin N.H., Nunn R.G. Habit-reversal: a method of eliminating nervous habits and tics. Behav Res Ther 1973;11(4):619–628.