Trichotillomania

Trichotillomania (also known as hair-pulling disorder) is an obsessive-compulsive and related disorder characterized by a long term, irresistible urge to pull out one's hair. The hair pulling occurs to the degree that significant hair loss occurs.

• Prevalence is 1-2% in the general population.^[1]
• It affects significantly more females than males with a ratio of 10:1.
  • Among children with trichotillomania, males and females are more equally represented.^[2]

• Hair pulling may be seen in infants, but this behaviour typically resolves early in development.
• The onset of hair pulling seen in trichotillomania most commonly coincides with, or follows the onset of, puberty.^[3]
  • The usual course of trichotillomania during this later onset is chronic, with waxing and waning of symptoms if the disorder is untreated (over periods of weeks, months, or sometimes years).
• Symptoms may worsen in females with hormonal changes (e.g. - menstruation, perimenopause).
  • Some individuals may achieve full remission without relapse.^[4]
• There may be irreversible damage to hair growth and hair quality for some individuals. Infrequent medical complications include digit purpura, musculoskeletal injury (e.g. - carpal tunnel syndrome; back, shoulder and neck pain), blepharitis, and dental damage (due to hair biting).
  • If there is swallowing of pulled hair (trichophagia), this may lead to trichobezoars (which lead to anemia, abdominal pain, hematemesis, nausea and vomiting, bowel obstruction, and/or perforation).

• The majority of individuals also have one or more other body-focused repetitive behaviors, including skin picking, nail biting, and lip chewing.^[5]
• There is a high comorbidity with major depressive disorder, OCD, excoriation disorder, body dysmorphia, and tics.^[6]

• Trichotillomania is more common in individuals with obsessive-compulsive disorder (OCD), and their associated first-degree relatives.^[7]

Recurrent pulling out of one's hair, resulting in hair loss.

Repeated attempts to decrease or stop hair pulling.

The hair pulling causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.

The hair pulling or hair loss is not attributable to another medical condition (e.g. - a dermatological condition).

The hair pulling is not better explained by the symptoms of another mental disorder (e.g. - attempts to improve a perceived defect or flaw in appearance in body dysmorphic disorder).

• Hair pulling may be accompanied by a range of behaviours or rituals involving hair such as:
  • Searching for a particular kind of hair to pull (e.g. - hairs with a specific texture or color)
  • Pulling out hair in a specific way (e.g. - so that the root comes out in tact)
  • Or may visually examine or tactilely or orally manipulate the hair after it has been pulled (e.g. -rolling the hair between the fingers, pulling the strand between the teeth, biting the hair into pieces, or swallowing the hair).
• The hair pulling may also be preceded or accompanied by different types of emotional states, individuals may:
  • Be triggered to pull hair by feelings of anxiety or boredom
  • Or it may be preceded by an increasing sense of tension (either immediately before pulling out the hair or when attempting to resist the urge to pull)
  • Or hair pulling may lead to gratification, pleasure, or a sense of relief when the hair is pulled out.
• The hair pulling can occur from any region of the body where hair grows, with the most common sites being the scalp, eyebrows, and eyelids (less common sites are the facial, pubic, axillary, and peri-rectal regions)^[8]
• Hair pulling may occur in brief episodes scattered throughout the day or during less frequent but more sustained periods that can continue for hours.
  • Hair pulling can sometimes persist for years.
• Individuals may attempt to conceal or camouflage hair loss (e.g. - with makeup, scarves, or wigs).

• Data regarding the pathophysiology of trichotillomania are limited. Animal models of trichotillomania show that certain genes may be associated with excessive grooming behaviours.
• From a psychopathology perspective, hair pulling may help regulate emotional states or stressful events
  • Hair pulling may function as a means of escaping from or avoiding aversive experiences, and provide temporary relief from negative emotions. These behaviours may be maintained through a negative reinforcement cycle

• Skin biopsy and dermoscopy can allow clinicians to differentiate trichotillomania from other causes of alopecia (although this is rarely needed, as patients commonly admit to hair pulling behaviours)
  • Dermoscopy shows decreased hair density, short vellus hair, and broken hairs with different shaft lengths.^[10]

• Patterns of hair loss are highly variable in trichotillomania. Areas of complete alopecia, as well as areas of thinned hair density, are common.
  • Eyebrows and eyelashes may be completely absent.
• If the scalp is involved, hair may most likely be missing in the crown or parietal regions.
• There may be a pattern of nearly complete baldness except for a narrow perimeter around the outer margins of the scalp, particularly at the nape of the neck (called “tonsure trichotillomania”).

• Except for clomipramine, which has shown some proven benefit in studies, SSRIs/SNRIs are generally ineffective for trichotillomania.
• Alternatively, antipsychotics such as olanzapine may be beneficial as primary medications.^[11]
• Small studies have also shown promising results for N-acetylcysteine and naltrexone.^[12]