
Hair Disorders: Finding the Root of the Problem
Hair loss, or alopecia (from Greek alopex, "fox," originally referring to mange in foxes), can be associated with a wide variety of conditions, from genetic to autoimmune to infectious to environmental. Common forms of hair loss include the following:
- Androgenetic alopecia (male or female pattern baldness)
- Alopecia areata
- Scarring (cicatricial) alopecia
- Telogen effluvium
- Anagen effluvium
- Congenital hypotrichosis
- Infection-related hair loss (eg, tinea capitis and folliculitis)
- Physical hair damage or defect (eg, trichotillomania, loose anagen syndrome, monilethrix, and overprocessing)
Androgenetic alopecia is by far the most common form of hair loss, followed by telogen effluvium, alopecia areata, tinea capitis, scarring alopecia, and hair loss from overprocessing.[1]
Hair Disorders: Finding the Root of the Problem
Androgenetic alopecia is a genetically determined disorder characterized by the gradual conversion of terminal hairs into indeterminate and finally into vellus hairs (shown).[2] This condition is known to affect both men and women but is generally considered to be more common in males than in females (although it has been suggested that the apparent differences in incidence may reflect sex-related differences in expression).
In men, androgenetic alopecia typically presents as gradual thinning in the temporal areas, which leads to reshaping of the anterior part of the hairline; baldness commonly progresses in accordance with the Norwood-Hamilton classification.[3] In women, androgenetic alopecia usually presents with diffuse thinning on the crown rather than an area of marked baldness; progression is commonly measured according to the Ludwig scale.[4] Bitemporal recession does occur in women but usually to a lesser degree than in men. The frontal hairline is often preserved in women with androgenetic alopecia, whereas men note a gradual recession of the frontal hairline early in the process.
Hair Disorders: Finding the Root of the Problem
A 34-year-old woman presents with a history of sudden-onset diffuse hair shedding. She gave birth to her first child 4 months ago after an uncomplicated pregnancy. A hair pull demonstrates hairs that predominantly have the morphology shown on the left side of the image.
Which of the following is the most likely diagnosis?
- Loose anagen syndrome
- Androgenetic alopecia
- Anagen effluvium
- Telogen effluvium
Hair Disorders: Finding the Root of the Problem
Answer: D. Telogen effluvium.
A finding of more than two or three telogen hairs on a hair pull is diagnostic of telogen effluvium. Pregnancy causes a physiologic telogen effluvium, as in this patient, following the prolonged anagen phase induced by pregnancy. Telogen effluvium can be triggered by systemic illness, high fever, surgery, psychological stress, crash dieting, medications, and endocrinopathies.[5] If the history does not point to a clear trigger, the workup should include assessment of thyroid function, a complete blood count (CBC), and measurement of serum ferritin.[5]
Answer A is incorrect because the hair on the left is a club-shaped telogen hair, whereas loose anagen syndrome is characterized by anagen hairs with a ruffled cuticle. Answer B is incorrect because androgenetic alopecia in women does not present as sudden-onset shedding; instead, it presents with gradual thinning at the temples and along the part. The thinning along the part widens toward the frontal hairline, which is characteristically spared. Answer C is incorrect because anagen effluvium usually results from fractures in the hair shaft, and telogen hairs that are not actively growing are unaffected. Anagen effluvium is most commonly seen with chemotherapeutic agents, but it can also be seen with boron, thallium,[6] isoniazid, and heavy-metal ingestion.
Hair Disorders: Finding the Root of the Problem
Which of the following diagnoses is most consistent with the morphology shown in the image?
- Anagen effluvium
- Loose anagen syndrome
- Pili triangulati (trianguli) et canaliculi
- Normal hair
Hair Disorders: Finding the Root of the Problem
Answer: B. Loose anagen syndrome.
The hair mount in the slide demonstrates the bent matrix and ruffled cuticle of loose anagen syndrome, which gives the hairs a "rumpled sock" appearance. In loose anagen syndrome, abnormal keratinization of the inner root sheath leads to poor adherence of hairs within follicles. Hairs can be pulled from the scalp easily and painlessly on examination. The classic patient is a young, blonde, white female with short blonde hair that rarely needs to be cut. No treatment is available, but the condition often improves with age.[7]
Answer A is incorrect because anagen effluvium causes tapering of the hair shaft that results from temporary shutdown of the hair matrix leading to fractures of the hair; a ruffled cuticle would not be visualized. Answer C is incorrect because pili triangulati (trianguli) et canaliculi results in stiff "uncombable" hair that sticks out from the scalp. It is also caused by abnormal keratinization of the inner root sheath that causes a triangular, grooved shape in the hair shafts. Adherence of hairs to the follicles is unaffected. Answer D is incorrect because the morphology is not that of normal hair.
Hair Disorders: Finding the Root of the Problem
A 6-month-old female presents to the clinic with her mother and a history of hair that has been brittle since birth. Evaluation of a hair clipping on light microscopy reveals the morphology shown in the image.
Which of the following findings is often associated with this condition?
- Cardiomyopathy and keratoderma (Naxos disease)
- Exfoliative erythroderma and atopy
- Keratosis pilaris and nail changes
- Sensorineural hearing loss
Hair Disorders: Finding the Root of the Problem
Answer: C. Keratosis pilaris and nail changes.
The findings noted in this patient are consistent with monilethrix (beaded hair; arrows), which is an autosomal dominant hair-shaft abnormality that leads to increased hair-shaft fragility. It is caused by mutations in the hair-cortex keratin genes KRT86 and KRT81. Abnormal hairs are usually limited to the scalp, but the condition can affect the eyebrows and eyelashes in some cases. Patients commonly have associated follicular hyperkeratosis (keratosis pilaris) and may have leukonychia or koilonychia.[7,8]
Answer A is incorrect because Naxos disease is characterized by wooly hair and diffuse nonepidermolytic palmoplantar keratoderma; it is not associated with beaded hair. Answer B is incorrect because hair-shaft abnormalities in association with exfoliative erythroderma and atopy are suggestive of Netherton syndrome. Patients with Netherton syndrome have a characteristic hair-shaft abnormality, trichorrhexis invaginata (bamboo hair); defective cornification of the hair shaft causes fragility and allows intussusception of the hair shaft, which yields an appearance resembling that of nodes on a bamboo plant. Pili torti (twisted hairs) and trichorrhexis nodosa are also frequently seen but are not specific for this syndrome. Answer D is incorrect because sensorineural hearing loss is not associated with monilethrix but is found in Bjornstad syndrome, which is characterized by congenital deafness and brittle hair. The characteristic hair finding in this disorder is pili torti, in which hair shafts are flattened and twist on their own axis.
Hair Disorders: Finding the Root of the Problem
A 67-year-old postmenopausal woman with salt-and-pepper hair presents with a history of recent loss of all of her pigmented hair. She has noticed that her white hairs are unaffected.
Which of the following is the most likely diagnosis?
- Telogen effluvium
- Vitiligo
- Alopecia areata
- Normal aging
Hair Disorders: Finding the Root of the Problem
Answer: C. Alopecia areata.
Alopecia areata is an autoimmune disease in which activated T cells target follicular melanocytes. White hairs are often spared, and regrowing hairs initially are white and gradually repigment.[9]
Answer A is incorrect because whereas telogen effluvium can cause diffuse hair shedding, white hairs would not be preferentially spared. Answer B is incorrect because although vitiligo can cause depigmentation of the hair within vitiliginous areas, hair loss is not seen. Answer D is incorrect because whereas thinning of the hair is common after menopause, pigmented hairs are not preferentially affected.
Hair Disorders: Finding the Root of the Problem
A 43-year-old atopic woman presents with a several-year history of patchy hair loss followed by spontaneous regrowth in her scalp associated with pitting in her nails. Recently, she has been under significant stress, and she has developed many new patches all over her scalp.
Which of the following would be an appropriate initial treatment for this patient?
- Topical hydrocortisone cream
- Hydroxychloroquine
- Intramuscular triamcinolone 40 mg
- Intralesional triamcinolone injections
Hair Disorders: Finding the Root of the Problem
Answer: D. Intralesional triamcinolone injections.
The photograph shows exclamation-point hairs characteristic of alopecia areata (arrows); the periodic regrowth and nail pitting noted in the preceding slide are additional clues to the diagnosis. Intralesional corticosteroids injected every 4-6 weeks are often first-line therapy for limited alopecia areata and can be combined with topical steroids, topical minoxidil 5% foam, squaric acid, and topical anthralin cream.[9]
Answer A is incorrect because whereas topical corticosteroids can be useful, especially in younger patients who cannot tolerate injections into the scalp, topical steroids more potent than hydrocortisone are required. Fluocinolone or clobetasol solution can be applied to the scalp twice daily. Treatment for at least 3 months is required before regrowth is seen. Answer B is incorrect because antimalarial medications such as hydroxychloroquine, although often helpful for control of discoid lupus and lichen planopilaris, are ineffective in the treatment of alopecia areata. Answer C is incorrect because systemic steroids are not a treatment of choice for chronic alopecia areata. Although 80% of patients with alopecia totalis or universalis will respond to treatment with systemic corticosteroids, more than 50% will relapse with cessation of therapy. The risks of long-term steroid therapy outweigh the benefits.
Hair Disorders: Finding the Root of the Problem
Atopic dermatitis, asthma, and seasonal allergies are seen more commonly with alopecia areata, and antihistamine therapy may be helpful for these patients.[10] Higher frequencies of vitiligo, thyroid disease, autoimmune diseases, diabetes mellitus, and myasthenia gravis have also been noted in patients with alopecia areata, although most patients are otherwise healthy. Routine screening of these conditions is not recommended; instead, screening should be guided by associated symptoms.[7]
Hair Disorders: Finding the Root of the Problem
Alopecia areata often presents with round-to-oval patches of hair loss, most commonly on the scalp but sometimes involving eyebrows, eyelashes, and facial and body hair as well.[9] The beard is a common area of involvement in men. Additional clues to a diagnosis of alopecia areata include nail pitting and salmon-pink scalp erythema.
Several patterns of alopecia areata are recognized. In the reticular pattern (shown), many patches of hair loss coalesce, and new areas of loss begin as regrowth in others. The surface area involved at the time of presentation is not predictive of disease severity, which can range from localized disease to alopecia totalis (alopecia areata affecting the entire scalp) and alopecia universalis (alopecia areata affecting the entire scalp and all body hair).[9]
Hair Disorders: Finding the Root of the Problem
Clues to a diagnosis of alopecia areata include patchy hair loss, nail pitting, and salmon-pink scalp erythema.
Hair Disorders: Finding the Root of the Problem
Diffuse alopecia areata, which can affect the vertex or present with diffuse thinning, can be mistaken for androgenetic alopecia. White hairs are often spared, and the frontal hairline does not show the pattern of preservation seen in androgenetic alopecia.
Hair Disorders: Finding the Root of the Problem
Alopecia areata results in anagen effluvium. The lymphocytic inflammation at the level of the hair bulb causes a shutdown of the matrix. The result is a narrowing of the hair shaft, which results in a tapered fracture.
Hair Disorders: Finding the Root of the Problem
A 22-year-old woman has a 2-week history of patchy hair loss involving her scalp.
Which of the following is the most appropriate next step in management?
- Hair pull
- Rapid plasma reagin (RPR) test
- Biopsy
- Intralesional triamcinolone injections
Hair Disorders: Finding the Root of the Problem
Answer: B. Rapid plasma reagin (RPR) test.
A diagnosis of syphilitic alopecia should always be considered in cases of patchy hair loss with a "moth-eaten" appearance as shown (arrows).[7] The number of new cases of syphilis has steadily increased since 2001, and alopecia can be the presenting symptom of this protean infection.
Answer A is incorrect because a hair pull is more helpful in the diagnosis of telogen effluvium. Answer C is incorrect because although biopsy could lead to the diagnosis of syphilis, less invasive testing is always preferred when possible. Answer D is incorrect because although a diagnosis of alopecia areata could be considered in this case, the relatively rapid onset of symptoms and the moth-eaten appearance warrant further workup for syphilis.
Hair Disorders: Finding the Root of the Problem
An 8-year-old girl presents with school phobia and the pattern of alopecia shown in the image.
Which of the following is the most likely diagnosis?
- Alopecia areata
- Trichotillomania
- Lichen planopilaris
- Lupus erythematosus
Hair Disorders: Finding the Root of the Problem
Answer: B. Trichotillomania.
The association with stress or other compulsive disorders and the typical appearance of broken and twisted short hairs, follicular hemorrhage, and a spared peripheral fringe are characteristic of trichotillomania.[11]
Answer A is incorrect because alopecia areata rarely produces a spared peripheral fringe of hair. Answer C is incorrect because lichen planopilaris would present with scarring alopecia. Answer D is incorrect because lupus erythematosus would also present with scarring alopecia.
Hair Disorders: Finding the Root of the Problem
Which of the following diagnoses is most consistent with the clinical findings shown in the image?
- Alopecia areata
- Androgenetic alopecia
- Discoid lupus
- Trichotillomania
Hair Disorders: Finding the Root of the Problem
Answer: D. Trichotillomania.
This angular, irregular patch of hair loss with broken hairs of varying lengths is strongly suggestive of trichotillomania. Hairs appear dark at sites of repetitive tugging and pulling. In cases where a definitive diagnosis is difficult, biopsy can be helpful.[11]
Answer A is incorrect because alopecia areata presents with patches of hair loss that are round to oval. Answer B is incorrect because pattern hair loss causes thinning and miniaturization of hair follicles at the temples and vertex. Answer C is incorrect because discoid lupus presents with scarring alopecia. In addition, this lesion is relatively pauci-inflammatory and angular, which would be unusual for lupus.
Hair Disorders: Finding the Root of the Problem
In which of the following circumstances should a biopsy be considered in the diagnosis of alopecia?
- When scarring is evident or suspected
- When alopecia areata is resistant to treatment
- When there is concern about diffuse alopecia areata
- All of the above
Hair Disorders: Finding the Root of the Problem
Answer: D. All of the above.
When scarring is evident or suspected, biopsy should always be performed to establish a diagnosis and guide treatment; however, this statement does not render the other answers incorrect. Presumed alopecia areata that is not responsive to treatment should prompt further evaluation to confirm the diagnosis. Alopecia secondary to lupus erythematosus can be subtle and present with alopecic patches suggestive of alopecia areata. Alopecia neoplastica caused by breast cancer metastasizing to the scalp can present as a solitary round alopecic patch. Diffuse alopecia areata can be mistaken for androgenetic alopecia clinically; thus, when there is concern about diffuse alopecia areata, biopsy is needed to establish the diagnosis. Biopsy can also be helpful in cases of moth-eaten alopecia to establish a diagnosis of syphilitic alopecia, as well as in cases of trichotillomania, a diagnosis that can be difficult to establish because patients often are not forthcoming about the history.[11]
Hair Disorders: Finding the Root of the Problem
A 37-year-old white woman presents with a year-long history of insidious-onset patchy hair loss associated with tenderness and pruritus of the scalp. On examination, she has scattered alopecic patches with perifollicular erythema and scale and a few atrophic white areas with loss of the follicular ostia. You are concerned about a scarring process and would like to perform a biopsy.
Which of the following is the best site from which to obtain the biopsy specimen?
- A white atrophic area with no erythema or scale
- The edge of an alopecic patch
- An area of active inflammation, well established for at least 3 months
- An area of normal-appearing scalp
Hair Disorders: Finding the Root of the Problem
Answer: C. An area of active inflammation, well established for at least 3 months.
This patient's presentation is concerning for lichen planopilaris. The biopsy specimen should be obtained from a well-established area of active inflammation to capture the characteristic histologic findings of a lichenoid lymphocytic infiltrate and vacuolar interface dermatitis with formation of Civatte bodies at the level of the follicular infundibulum. In conditions such as lupus erythematosus, direct immunofluorescence is not reliably positive in new lesions; the yield is much higher in lesions established for 3-6 months.
Answer A is partially correct. Ideally, a biopsy should be performed on an area with active inflammation to maximize the chance of obtaining a specific diagnosis. If there is no visible inflammation, biopsy from a burnt-out scar is still helpful to suggest an end-stage scarring alopecia. In the case of lichen planopilaris, biopsy will show a superficial wedge-shaped scar highlighted by loss of elastic fiber staining within the scar on van Gieson staining. For lupus erythematosus, biopsies from well-established lesions will have the highest yield. Answer B is incorrect because changes at the edge of an alopecic patch are typically nonspecific. Answer D is incorrect because although biopsy of normal scalp can occasionally be of benefit for comparison of normal hair density, it will not lead to a specific diagnosis.
Hair Disorders: Finding the Root of the Problem
Perifollicular erythema and scale is characteristic of lichen planopilaris and frontal fibrosing alopecia. However, many cases are pauci-inflammatory. In these cases, a high index of suspicion and early biopsy are key to making the diagnosis.
Hair Disorders: Finding the Root of the Problem
A 56-year-old white woman presents with complaint of burning of her scalp and slow recession of her frontal hairline. The most likely diagnosis is:
- Androgenetic alopecia
- Telogen effluvium
- Frontal fibrosing alopecia
- Trichotillomania
Hair Disorders: Finding the Root of the Problem
Answer: C. Frontal fibrosing alopecia.
The relatively pauci-inflammatory recession of the frontal and temporal hairline with loss of follicular ostia (shown) is characteristic of frontal fibrosing alopecia, which is seen most commonly in perimenopausal women.[7] The arrows illustrate the area of involvement, extending from the patient's original hairline to the new hairline with scattered "lonely hairs" within a hypopigmented scar. Eyebrow involvement is common and can be a helpful clinical clue in subtle cases. An increasing incidence of this condition potentially suggests an environmental trigger. Survey data indicate an association with facial moisturizers, leave-on cosmetics, and sunscreens in affected men and women,[12] although it is unknown if these products are causative. Nanoparticle titanium dioxide, nearly ubiquitous in cosmetic products, has been demonstrated along the hair shafts of affected individuals[13]; a mechanism involving allergic contact sensitization akin to that caused by dental amalgam in lichenoid stomatitis has been suggested.[13,14] Further study is needed to better understand the pathogenesis of frontal fibrosing alopecia.
Answer A is incorrect. Androgenetic alopecia generally spares the frontal hairline and does not result in a scar. Answer B is incorrect because telogen effluvium causes a diffuse pattern of hair loss without scarring. Answer D is incorrect. Trichotillomania causes irregular patches of hair loss with twisted and broken hairs.
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