Skin nontumor
Alopecia
Trichotillomania
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PubMed Search: Trichotillomania
Table of Contents
Definition / general | Essential features | Terminology | ICD coding | Epidemiology | Sites | Pathophysiology | Etiology | Clinical features | Diagnosis | Prognostic factors | Case reports | Treatment | Clinical images | Microscopic (histologic) description | Microscopic (histologic) images | Sample pathology report | Differential diagnosis | Additional references | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Rahmati D, Zare P, Ramezani M. Trichotillomania. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumortrichotillomania.html. Accessed December 30th, 2024.
Definition / general
- Repeated pulling out of one’s own hair (compulsive desire); obsessive compulsive and related disorders in the International Classification of Diseases 11th Revision and the Diagnostic and Statistical Manual Version 5 (WHO: International Classification of Diseases 11th Revision [Accessed 24 April 2024], APA: Diagnostic and Statistical Manual of Mental Disorders, Text Revision DSM-5-TR, 5th Edition, 2022)
Essential features
- Recurrent hair pulling and hair loss (unavoidable) with significant distress not related to another medical or mental disorder under obsessive compulsive disorder (OCD) / related disorders
- Variability in length of hairs in patches of alopecia
- Otherwise normal scalp
Terminology
- Hair pulling disorder
- Trichotillosis
Epidemiology
- More common in children
- Peak in the preschool years and early adolescence
- F:M = 4:1 in adults
- F = M in children
- Lifetime prevalence of 2%
- Reference: Am J Psychiatry 2016;173:868
Sites
- Scalp, eyebrows and eyelashes and pubic area are the most common sites (Psychiatry Res 2020;288:112948)
Pathophysiology
- Traumatic alopecia, multifactorial, anxiety, stress
Etiology
- Not well understood; genetic, psychological, social and neurobiological (Skin Appendage Disord 2022;8:1)
Clinical features
- Hair of varying length in alopecia patch with otherwise normal scalp
Diagnosis
- Clinical features, trichoscopy, microscopic features
- Trichoscopy plays a vital role in the diagnosis of this condition by demonstrating specific trichoscopic patterns
- Common trichoscopic feature is decreased hair density and broken hairs
- Trichoptilosis (split ends) and irregular coiled hairs (up to 80%)
- Novel diagnostic signs such as black dots, flame hair, V sign and follicular hemorrhages (up to 30% each)
- Tulip hair and hair powder were observed in 10% of patients
- Reference: Int J Trichology 2014;6:160
Prognostic factors
- In children: benign and self limiting (Am J Clin Dermatol 2001;2:327)
- In adolescents and adults: chronic (Dermatol Ther 2008;21:13)
Case reports
- 4 year old girl with low hair density without any patch in the occipital and parietal region and a 14 year old girl with hair loss due to increased anxiety (Skin Appendage Disord 2021;7:131)
- 9 year old boy who had suffered from nocturnal enuresis (bedwetting) presented with a history of recurrent episodes of local hair loss of the eyelashes (Case Rep Ophthalmol Med 2019;2019:4650217)
- 12 year old girl, previously diagnosed with alopecia areata, had an uncontrollable urge to manipulate the scalp when she was nervous (An Bras Dermatol 2017;92:118)
- 25 year old woman with a past history of attention deficit hyperactivity disorder (ADHD) and major depressive disorder (MDD) with symptoms of involuntary hair pulling, binge eating attacks and excessive exercise (Clin Case Rep 2023;11:e7800)
Treatment
- Habit reversal therapy
- N-acetyl cysteine
- Olanzapine
- Clomipramine
- Dronabinol (cannabinoid agonist)
- Reference: Indian J Psychiatry 2019;61:S136
Clinical images
Images hosted on other servers:
Irregular shaped patch of hair loss
Bizarre shaped alopecia patch
Eyelashes and scalp
Trichoscopic features
Microscopic (histologic) description
- Nonscarring alopecia
- Morphological changes of follicular damage secondary to the external insult
- Empty follicles
- Distorted follicular anatomy
- Perifollicular and intrafollicular hemorrhage
- Trichomalacia (collapse of hair with distorted hair shaft and clumps of pigment)
- Melanin pigment casts
- Incomplete cornification and irregular pigmentation
- Increased catagen / telogen hair follicles
- Absence of significant inflammation and collapse of inner root sheath
- Reference: Skin Appendage Disord 2022;8:1
Microscopic (histologic) images
Contributed by Donya Rahmati, M.D., Pooria Zare, M.D., M.P.H. and Mazaher Ramezani, M.D.
Trichomalacia
Absence of inflammation
Empty follicle
Irregular pigmentation
Pigment cast and follicular rupture
Pigment cast
Melanin pigment cast and trichomalacia
Incomplete cornification
Distorted follicular anatomy
Follicular damage
Incomplete pigment cast, follicular rupture
Sample pathology report
- Scalp (parietal), skin biopsy:
- Nonscarring alopecia compatible with trichotillomania (see comment)
- Comment: Distorted follicular anatomy and pigment cast is in favor of diagnosis, trichomalacia and increased non-anagen hairs.
Differential diagnosis
- Different types of alopecia
- Alopecia areata:
- Shift out of anagen and relatively less trichomalacia compared with trichotillomania
- Peribulbar lymphoid cell infiltrate, empty infundibula
- Traction alopecia:
- Early phase like trichotillomania, late phase with marked loss of terminal follicles, fibrous tissue at isthmus (scarring)
- Androgenic alopecia:
- Miniaturization, increased vellus hairs, anisotrichosis
- Pseudopelade of Brocq:
- End stage cicatricial alopecia
- Alopecia mucinosa:
- Intrafollicular mucin and lymphocytes
- Alopecia areata:
- References: Pediatr Clin North Am 2014;61:427, An Bras Dermatol 2017;92:118, Histopathology 2010;56:24
Additional references
Board review style question #1
A 16 year old girl, with a patch of alopecia on the scalp above the ear with varying hair lengths, has undergone skin biopsy. What is the most probable diagnosis according to histopathology and clinical presentation?
- Androgenetic alopecia
- Folliculitis decalvans
- Lichen planopilaris
- Trichotillomania
Board review style answer #1
D. Trichotillomania. Trichotillomania is mainly seen in adolescence with distorted hair follicle, pigment cast and follicular rupture. Answer B is incorrect because this type of alopecia is mainly on occiput with prominent mixed inflammation composed of neutrophils, plasma cells and lymphocytes. Answer C is incorrect because lichen planopilaris is a scarring lymphocytic alopecia. Answer A is incorrect because androgenic alopecia shows miniature hairs, prominent sebaceous glands and anisotrichosis.
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Reference: Trichotillomania
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Board review style question #2
Which of the following is the best clinical diagnosis for a 9 year old girl with alopecia on the scalp, eyebrows and eyelashes with varying lengths and an otherwise normal scalp?
- Alopecia areata
- Dissecting cellulitis of scalp
- Lichen planopilaris
- Trichotillomania
Board review style answer #2
D. Trichotillomania. Trichotillomania is typically seen in children, mainly girls with varying hair lengths on scalp, eyebrows and eyelashes. Answer B is incorrect because dissecting cellulitis of scalp is found mainly on occiput and vertex. Involvement of eyebrows and eyelashes is not a feature of this entity. Answer A is incorrect because varying hair lengths is not a feature of alopecia areata. Answer C is incorrect because lichen planopilaris is scarring alopecia and does not typically occur in this age group.
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