Diagnostic criteria (DSM-5) .
Trichotillomania and traction alopecia are chronic habitual disorders characterized by repetitive pulling of hair that results in alopecia. They are commonly observed in children and adolescents but may present in adults due to occupational or traditional behavioral patterns. Trichotillomania (hair‐pulling disorder) has been described more than a century ago, but we still have very limited data about its etiology and treatment. It is classified under the obsessive‐compulsive and related disorders along with hoarding disorder, skin‐picking disorder (excoriation) and body dysmorphic disorder in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM‐5; American Psychiatric Association, May 2013). Traction alopecia is defined as loss of hair caused by repetitive or continuous and prolonged tension applied to the hair, usually on the scalp periphery and associated with mechanical traction of hair due to occupational behavioral patterns such as ballerinas or traditional behavioral patterns of hairstyles that cause tension. We aim to overview the clinical and diagnostic features of trichotillomania and traction alopecia and review the therapeutic options of these disorders in this chapter.
- hair loss
- psychosomatic disorders
- traction alopecia
Trichotillomania is the disorder of repetitively pulling out one's hair from different areas of the body that results in noticeable hair loss . The name trichotillomania was given to this behavior by a French dermatologist, Francois Henri Hallopeau, in 1889; however, the disorder also appears in the literature in the works of Hippocrates. It is even found in plays by William Shakespeare such as Romeo and Juliet and The Life and Death of King John. The name is derived from the combination of Greek thrix for hair; tillein, plucking; and mania, madness.
Trichotillomania is classified under the obsessive‐compulsive and related disorders along with hoarding disorder, skin‐picking disorder (excoriation) and body dysmorphic disorder in the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM‐5; American Psychiatric Association, May 2013)  (Table 1). It is also grouped under obsessive‐compulsive disorders in the eleventh revision of the World Health Organization's International Classification of Diseases and Related Health Problems (ICD‐11) .
|• Recurrent pulling out of one’s hair, resulting in hair loss|
|• Repeated attempts to decrease or stop the pulling out of hair|
|• 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|
|• The hair pulling is not better explained by the symptoms of another mental disorder|
Trichotillomania occurs more frequently in females. The lifetime prevalence is 3.4% for women and 1.5% for men . The typical age of onset is between 5 and 12 years or early childhood to adolescence, but it may occur in any age.
The onset of trichotillomania often occurs after a stressful event such as the divorce of parents, loss of a loved one or unemployment . Occasionally, trichotillomania is only seen while sleeping, a condition known as sleep‐isolated trichotillomania .
1.4.1. Clinical features
Patients may have other problems with self‐mutilation such as nail‐biting or dermatitis artefacta. Approximately one‐third of the patients chew or swallow the hair they pull out, which is called trichophagia and some of them develop trichobezoars, which is the accumulation of the patients’ own hair in the intestines. These trichobezoars may result in a “tail” that lies along the duodenum, a phenomenon which is called Rapunzel Syndrome. Around 1% of trichobezoar patients may need surgical intervention .
Symptom severity can be measured by using different validated instruments including Massachusetts General Hospital Hair Pulling Scale that has seven parameters, rating symptom severity from 0 to 4 and assessing various aspects of plucking during the past seven days: actual pulling, urge to pull, associated distress and perceived control, The Yale‐Brown Obsessive‐Compulsive Scale, The Psychiatric Institute Trichotillomania Scale, The Trichotillomania Scale for Children, The Milwaukee Inventory for Styles of Trichotillomania‐Child Version . The MGHHS includes seven parameters, rating symptom severity from 0 to 4 and assesses several aspects of hair pulling during the previous 7 days: urge to pull, actual pulling, perceived control and associated distress. The MGHHS and its Dutch adaptation have been reported to provide good psychometric properties .
Three subtypes of hair pulling have been described (Table 2).
|• Early onset: occurring in young children, mostly under the age of 8; usually does not need any treatment.|
|• Automatic: occurring when the individual is busy with other activities, such as reading. This type affects 75% of patients.|
|• Focused: occurs with the patient's attention and is associated with strong impulses to pull hair.|
Any part of the hair may be affected, but the targeted hair is mostly on the scalp (75%). The eyelashes (53%), eyebrows (42%), pubic region (17%) and beard (10%) may also be involved, but sometimes there is more than one location (17%) [8, 9]. The most affected scalp areas are the frontoparietal region and vertex, while the least affected region is the occiput. The lower eyelid is usually not involved; this is helpful to distinguish trichotillomania from alopecia areata .
Alopecic plaques are usually located on the contralateral side of the dominant hand. There may be more than one plaque. These plaques of hair loss most often have irregular shapes and contain many broken hairs of varying lengths. The margins have normal and long hair.
The plucked hairs have fiber fractures and feel rough on examination. There are usually no signs of inflammation in the plaques, but there may also be signs of excoriation, lichenification and post‐inflammatory hyperpigmentation in some cases.
Trichoscopy may also be utilized for differential diagnosis. The trichotillomania plaque includes broken and irregular coiled hair and hair density is decreased. Black dots, follicular hemorrhages and V‐sign may be seen . Trichoscopy is very useful in the differential diagnosis of trichotillomania from alopecia areata where exclamation mark hairs, yellow dots and proximal tapering hairs could be seen, in contrast with trichotillomania where trichoptilosis, pointed hairs, flame hairs, V‐sign, hook hairs, hair powder, follicular microhemorrhage and tulip hairs are more characteristic. Follicular microhemorrhage meaning a red dot that corresponds to a follicular ostium stuffed with blood clot, may support local trauma, a clue for trichotillomania .
The diagnosis of trichotillomania is usually made by clinical examination and patient history. However, occasionally especially in pediatric patient group both child and parents may deny the possibility of pulling or plucking as a cause of hair loss and especially in localized involved patients the diagnosis may be difficult. Histopathological examination may be necessary in these patients. Follicules of normal size, increased catagen and telogen hairs (up to 75%) which is a result of mechanical trauma to the hair frequently propelling anagen follicules into the catagen phase, pigmentary defects and casts, evidence of traumatized hair bulbs and trichomalacia (a complete but distorted, fully developed terminal hair in its bulb) are the most common findings in histological examination of trichotillomania [13, 14]. Catagen hairs may be present in areas that have recently been injured and telogen hairs may present after a few weeks from pulling. Some hair follicles in anagen phase may be present, but they are usually seen empty because of hair shaft avulsion. If the hair matrix and suprabulbar epithelium are injured, but not severely disrupted, the follicle may remain in the anagen phase which may produce a hair shaft. Follicles can show distortion of the bulbar epithelium and sometimes conspicuous hemorrhage.
Hair shaft avulsion may deposit melanin pigment in the hair papilla and peribulbar connective tissue [13, 14]. Frequently, chunks of pigmented hair matrix or cortex cells are torn from their moorings during the plucking process and come to rest in superficial portions of the follicles. These cells then shrink to form a dark black homogeneous clump called a pigment cast. Pigment casts which are very characteristic for trichotillomania simply occur as the by‐product of fragmented, ectopic matrix or cortical epithelium and usually seen in the isthmus or infundibulum. Trichomalacia, which defines shaft abnormalities such as distorted in shape, smaller than normal and incompletely cornified, is very characteristic for trichotillomania.
These injuries of pulling or plucking to the bulbar portions of follicles do not induce inflammation but may cause follicular microhemorrhage within the lower portion of the follicle. A few eosinophils may be rarely seen around the lower portion of the traumatized follicule. Also miniaturization of follicules is usually not seen in trichotillomania and absence of inflammatory infiltrate and loss of miniaturization are usually serve to differentiate it from alopecia areata .
1.5. Differential diagnosis
Tinea capitis, alopecia areata, loose anagen hair, monilethrix, lichen planopilaris and secondary syphilis need to be considered in the differential diagnosis of trichotillomania. Trichoscopy, medical history and scalp biopsy can be used to distinguish trichotillomania from other diseases. Catagen and telogen hair numbers are found to be increased and usually there are no signs of inflammation unless there is an infection in histologic examination. The number of catagen hairs exceeds telogen hairs in chronic lesions. Perifollicular hemorrhage may be found at the circumference of the hair bumbs .
Potassium hydroxide examination, fungal culture and Wood's lamp examination may be performed to exclude tinea capitis. The hair is weak and may easily be pulled out in tinea capitis.
Alopecia areata plaques are oval and well‐demarked. A hair pull test may be helpful as a diagnostic test for alopecia areata. Telogenic hairs may be pulled out easily in alopecia areata, which indicates the activity of the disease in contrast with trichotillomania. Shaving the involved area and waiting for the regrowth may also be useful for the diagnosis of trichotillomania. Alternatively, a small part of the hair is clipped near the scalp with scissors and the hairs in trichotillomania display uniform hair regrowth.
Trichoscopy may also be utilized for differential diagnosis. Exclamation mark hairs and yellow dots may be seen and white hairs are usually not involved in alopecia areata . The trichotillomania plaque has broken and irregular coiled hair and the hair density is decreased. Black dots, follicular hemorrhages, v‐sign may be seen .
As mentioned above, trichotillomania is a psychiatric disorder with dermatological findings which is characterized by compulsive avulsion of hair shafts leading to thin, ragged, broken hairs on the affected region clinically . The inability to control self‐pulling of hair resulting in hair loss may progress into alopecia in long time.
Treatment procedure must be multidisciplinary including both dermatological but mainly psychiatric approach to increase the effectiveness of the therapy and prevent relapse.
Cognitive and behavioral therapies (CBT), antipsychotic agents, selective serotonin reuptake inhibitors (SSRI), tricyclic antidepressants are the main options of treatment [7, 16–18]. The most appropiate therapeutic approach must be chosen according to the patient's age, medical status and mental status.
Cognitive and behavioral therapies are the first steps of treatment and must be considered together with pharmacotherapeutics in treatment [16, 19]. In a randomized controlled trial with 7–8‐year‐olds, cognitive‐behavioral therapies alone were found to decrease the symptoms in 75% of the participants .
The results about efficacy of SSRIs are conflicting. They were reported to be the safest and well‐established medication choice. However, the clinical results show that medication, which is usually an SSRI, in addition to CBT, is more successful, if CBT alone fails.
In a meta‐analysis which was reported in 2007, in which the efficacies of pharmacologic and behavioral treatments were evaluated in treatment of trichotillomania, it was found that SSRIs were not more effective than placebo. In two trials clomipramine was found to be more effective compared with placebo. In three trials, it was shown that there is a beneficial effect of habit reversal therapy compared with no intervention .
In another systematic review which was published in 2013, similar results were found. In two included trials, fluoxetine was not more effective than placebo in reducing the mean severity rating of hair pulling. Clomipramine was found to be more effective than placebo, although 3 of 10 participants receiving clomipramine dropped out because of drug‐related adverse effects .
At last, in a recent meta‐analysis of 11 randomized trials, the efficacy of behavioral therapy and SSRI for the treatment of trichotillomania; the outcome measure was the standardized mean difference of change in hair pulling . This publication demonstrated a large effect for behavioral therapy and only a moderate effect for SSRI. A greater treatment effect was reported for clomipramine in two included trials .
The side effects and limited efficacy of pharmacological treatment, especially in pediatric population and difficulty in long‐term maintenance of behavioral therapies require alternative options of treatment. The glutamatergic system dysregulation is involved in obsessive‐compulsive disorders etiology and it has been reported that N‐acetyl‐cysteine (NAC) might have a therapeutic effect on these entities by acting on the glutamatergic system and reducing oxidative stress . It was reported as a safe and effective treatment option given 1200 mg/d per os. The efficacy of the glutamate modulator NAC was evaluated in a small randomized trial including 50 adults with trichotillomania . N‐acetylcysteine was more effective than placebo in reducing hair‐pulling symptoms as measured by the Massachusetts General Hospital Hair Pulling Scale. A subsequent trial in children and adolescents did not find any beneficial effect of NAC compared with placebo [24, 25].
2. Traction alopecia
Traction alopecia (TA) is defined as loss of hair caused by repetitive or continuous and prolonged tension applied to the hair [26–28]. It was first described using the terminology alopecia groenlandica to refer to the hair loss attributed to tight ponytails which girls and women wear in Greenland . Although TA is more prevalent among females of African ancestry, it has been described in a wide range of populations, including nurses, ballerinas, Sikh boys and men, to name a few [30–34]. Research has convincingly demonstrated that certain habitual practices of hairstyling are implicated in the pathogenesis of TA [35–39].
Most of the population‐based studies concerning the prevalence of TA originate from South Africa [35–37]. Overall, TA was found to be more common in females compared to males and in women compared to girls, presumably due to a longer history of hairdressing . Importantly, in a large cohort of African adults in Cape Town, almost one‐third of women had findings consistent with TA on scalp examination . Of note, 17.1% of South African schoolgirls had TA, with increasing prevalence rates from the first year of school to the last year of high school . A similar rate (18.4%) was observed in another study examining a population of 201 African American girls from the United States . In males, TA seems to be considerably less prevalent, however, two notable exceptions are Sikh boys and men, who adhere to the religious practice of tightly knotting their scalp and/or beard hair and boys/men wearing dreadlocks or cornrows [32–35, 40].
Traction alopecia is typically noncicatricial and reversible in its early stages, whereas it may progressively result in permanent scarring in the long term [27, 28, 41]. It is well recognized that traction causes an inflammatory, sometimes subclinical, folliculitis. The exact pathomechanism leading from follicular inflammation to follicle damage and hair loss remains to be elucidated; however, follicular miniaturization is considered to play a possible role [28, 42–44].
2.4. Predisposing factors
The factors predisposing to the development of TA fall into two major categories: (1) traumatic hairstyling practices and (2) application of chemicals and/or heat to the hair . It has been shown that the combination of both factors greatly increases the risk of TA, cautioning against the application of traction on chemically relaxed hair [36–38]. Importantly, hairdressing practices causing symptoms such as stinging, pain, or crusting are associated with an increased risk of TA [37, 39]. “Tenting” of the hair follicle, which manifests as elevation of the scalp skin due to tight pulling, has been interpreted as a sign of excessive tension [27, 39, 43]. A more recent literature review classified hairstyles into low risk, moderate risk and high‐risk . Accordingly, the excessive use of very tight buns or ponytails belongs to the category of high‐risk hairstyles, as do dreadlocks, cornrows and braids [38, 39, 45]. Another well‐recognized factor associated with TA is the use of hair extensions, especially if applied to relaxed hair [39, 46]. According to the aforementioned review, other hairstyles such as braids and/or weaves are considered high‐risk if they are combined with chemical relaxation of the hair . Moreover, hairpins used to fix the nurse's cap to the scalp may be related to hair loss . Alopecia initially presenting with a traumatic ulcer was described in association with hairstyles requiring multiple hairpins .
2.5.1. Clinical findings
Two main categories of TA have been recognized: marginal and nonmarginal . The former is more common and typically presents as bandlike loss of hair along the temporoparietal margin or frontal hairline (Figure 1) . Marginal TA is usually attributable to traumatic hairstyles, whereas nonmarginal TA may be caused by hairpins or buns [40, 47, 49]. A peculiar form of TA, termed “horseshoe pattern” by the authors, was described as a result of weft hair extensions . Hair loss in nonmarginal localizations may sometimes present a diagnostic challenge and require more detailed history taking and/or histopathological examination [27, 48].
The earliest clinical sign of TA is considered to be perifollicular erythema in the areas of the scalp exposed to maximum tension, which may progress to folliculocentric papules and pustules. However, these initial findings may be unrecognized by the patient and physician alike [22, 28, 31]. The presentation may be acute or more commonly, chronic and progressive. Patients may provide a history of symptoms such as stinging or tenderness during hairdressing practices . As noted earlier, the alopecia is typically nonscarring in the early stages, but may become irreversible later during the disease course, following a “biphasic” course . Correspondingly, follicular markings tend to be decreased in the late stages of TA [27, 31, 43]. An important clinical caveat in the diagnosis of TA is the “fringe sign,” defined as the presence of retained hairs along the frontal and/or temporal margin. This useful finding was observed in early and late stages of TA alike (Figure 2) .
In general, TA is considered to have no systemic associations. Nonetheless, there is an anecdotal report of a 25‐year‐old woman with prolonged traction resulting in a combination of TA, cutis verticis gyrata and intractable headache. Her headache resolved as she was advised to change her habitual hairstyle, which also stopped further hair loss .
Dermoscopy may be utilized as a useful aid to confirm the clinical diagnosis of TA and/or differentiate it from other entities presenting with hair loss. In a cross‐sectional study from Korea, broken hairs and black dots were observed in 100 and 92% of patients with TA, respectively. Of these findings, broken hairs were noted in all patients with trichotillomania, as well (Figure 3). Other dermoscopic findings associated with TA in this study were clustered short vellus hairs, yellow dots and atypical red vessels, with decreasing frequency . The presence of hair casts has been emphasized as an important dermoscopic sign of TA, described as cylindrical structures encircling the proximal hair shafts . It has been demonstrated that observation of hair casts on dermoscopic examination is an indicator of ongoing traction  and should be interpreted as a warning sign that hairstyle changes should be implemented to halt the progression of alopecia . More recently, the trichoscopic finding of “flame hairs”was reviewed in a population of patients with various hair disorders. Of note, flame hairs were noted in slightly more than one half of the patients with trichotillomania, whereas they were observed in less than 5% of patients with TA. This disparity was attributed by the authors to the extent of the acute mechanical damage to the hair follicle being more prominent in trichotillomania compared to that in TA .
Histologic findings of TA parallel the biphasic course of the disease mentioned previously . Early stages of TA are considered to resemble trichotillomania, whereas more advanced stages of TA are similar to “burned‐out” forms of cicatricial alopecia . More specifically, early TA is characterized by increased numbers of telogen and catagen hairs and trichomalacia. In contrast to primary scarring alopecias, sebaceous glands are generally preserved in TA (Figure 4). With prolonged traction, terminal follicles tend to decrease in number and are progressively replaced by fibrous tracts [27, 28, 43]. Furthermore, vellus‐sized hairs may be observed on histology which are thought to correspond to the aforementioned “fringe sign” noted on physical examination . Differentiation of late‐stage TA from primary scarring alopecias may be challenging and it has been demonstrated that transverse sections may be advantageous compared to vertical sections in differential diagnosis .
2.6. Differential diagnosis
The clinical differential diagnosis of TA depends on the distribution pattern of hair loss. For marginal type TA, the most important entities to be considered in the differential diagnosis are alopecia areata with an ophiasis pattern and frontal fibrosing alopecia [27, 43]. A noteworthy caveat is that TA only affects scalp hair exposed to traction, whereas body hair, eyebrows and/or nails may be involved in alopecia areata or frontal fibrosing alopecia . Another important differential diagnosis is androgenetic alopecia. These two conditions may also coexist and in fact androgenetic alopecia is thought to predispose an individual to the development of TA due to the miniaturized hairs [30, 40, 43]. Nonmarginal TA, on the other hand, may be considered within the differential diagnosis of a broad range of conditions, including alopecia areata, trichotillomania, telogen effluvium and discoid lupus erythematosus [40, 48].
Central centrifugal cicatricial alopecia (CCCA) is another condition mainly seen in females of African descent . The relationship between traction/TA and CCCA remains controversial . Ackerman and coauthors categorized CCCA as a form of TA,  and a retrospective comparative study detected a strong association between CCCA and the use of tractional hairstyles with artificial hair extensions . However, a more recent study failed to reveal an association between CCCA and tractional hairstyles. Interestingly, among more than 1000 female participants, not a single individual had a concomitant diagnosis of CCCA and TA in the same study, suggesting that CCCA and TA may not be closely related .
2.7. Prevention and treatment
Prevention is an integral part of management of TA, as appropriate measures to eliminate traction can stop hair loss before it becomes permanent [27, 28, 61]. It is important to recognize that TA most often originates during childhood and adolescence, suggesting that public education should primarily focus on these at‐risk populations [27, 43, 44]. Prevention strategies have been detailed elsewhere [39, 44]. Briefly, management should rely on two main principles: preferring loose hairstyles and avoiding heat and chemicals [27, 39]. Patients may be encouraged to switch from high‐risk hairstyles to low‐risk hairstyles, such as loose buns and ponytails . An important message is that pain during hairstyling be interpreted as a sign that excessive tension has been applied and that particular hairstyle should better be avoided [39, 44].
Medical or surgical treatment should only be considered after traction has been minimized . There is a paucity of evidence‐based literature data with regard to the medical treatment of TA. Topical or intralesional corticosteroids and topical or systemic antibiotics may be utilized to suppress the inflammation in the early stages of the disease .Topical minoxidil was described as effective in an anecdotal report  and recommended by some authors [27, 43, 61], although controlled trials are lacking. An interesting study demonstrated the protective effect of piloerection induced by topical phenylephrine against the development of TA, suggesting a potential role of α1‐adrenergic receptor agonists in the treatment of TA . For extensive TA, surgical treatment has been described [45, 62]. Of note, a scoring system was developed (“M‐TAS score”) to evaluate the severity of marginal type TA and facilitate assessment of treatment effectiveness .