Hair Disorders




  • Non-scarring reversible multifocal hair loss
  • Typically presents as rapid onset hair loss in a well-demarcated circular area
  • Can be limited to a few circular bald areas (alopecia areata circumscripta) or can lead to complete baldness of the head (alopecia areata totalis) or the whole body (alopecia areata universalis)


  • Lifetime risk: 1-2% (general population), 6% (children of affected parents)
  • No gender predilection
  • Onset usually occurs before the age of 20
  • An autoimmune disease involving complex gene-environment interactions
  • Associated with other autoimmune disorders especially Hashimoto’s thyroiditis, vitiligo, pernicious anemia and myasthenia gravis


  • Diagnosis is mostly based on clinical presentation.
  • If clinical presentation is atypical, microscopic examination of plucked hair and scalp biopsy may help establish diagnosis.
  • Differential diagnosis: Trichotillomania, tinea capitis, telogen effluvium

Clinical Features

  • Alopecia areata typically presents withthe sudden appearance of one or more well-defined circular areas of hair loss.
  • Patches can occur at any hair-bearing site but most common site is scalp (>90%).

Allopecia areata.JPG

  • It has an unpredictable course:
    • Acute hair loss is followed by spontaneous re-growth, with white hairs appearing first.
    • As hair starts to re-grow at one site, another bald patch can appear.
    • Hair loss can persist for many years.
  • Hair follicles are preserved and can re-grow after many years.
  • Nail involvement is seen in 10-20% of cases. Most characteristic finding is fine stippling and pitting of the nails in a diffuse and regular pattern.


  • No definitive options to cure disease or prevent relapseà can be frustrating
  • Available treatment modalities: corticosteroids (topical, intralesional, systemic), immunotherapy, anthralin, minoxidil, ultraviolet light phototherapy (UVB)




  • Non-scarring diffuse hair loss which can be:
    • Acute: occurs abruptly after a period of stress (e.g. severe medical illness or psychological stress, surgery, medications)
    • Chronic: inciting stressor often not identified, >12 months duration

Clinical Features


  • Hair loss is often frustrating and very noticeable to patient and is noted while showering or combing hair although less noticeable by others.
  • Acute: Hair loss typically occurs 3-5 months after the major stress as anagen (growing) phase hairs undergo a sudden shift into catagen (apoptotic) phase and then into telogen (resting) phase where hair loss occurs.
  • Chronic: It is thought to be caused by shortening of the anagen cycle.
  • Infants can experience an episode of telogen effluvium within the past 4 months of life with re-growth typically occurring in the first 6 months.


  • Diagnosis is usually clinical and based on history and physical examination.
  • Hair pluck test(rarely performed):>10 hairs are plucked from the scalp and examined under the microscope. Telogen to anagen ration of >1:10 is diagnostic.
  • Pull testis positive: Gentle traction of hair yields >3 telogen hairs.
  • Differential diagnosis: Androgenetic alopecia, alopecia areta (diffuse form)


  • Telogen effluvium is temporary in most cases with spontaneous re-growth.
  • Complete re-growth (<6 months) is expected unless inciting stimulus is repeated.
  • No treatment has been demonstrated to shorten course and hasten recovery.
  • Reassurance and education of the patient regarding hair dynamics is essential.
  • Topical application of minoxidil may be helpful for chronic telogen effluvium.




  • Characterized by androgen-dependent male pattern baldness


  • Can occur in both males and females
  • Can begin anytime after pubertyà Early onset associated with severe alopecia
  • Observed in 14% of healthy adolescent boys between ages 15-17
  • Has a significant genetic component

Clinical Features

  • Boys:
    • Triangular frontotemporal recession (type I) normally occurs in most adolescent boys undergoing puberty.
    • First sign of balding is increased mid-frontal recession (type II).
    • Hair shedding in a circular are on the vertex occurs resulting in a bald spot, followed by decrease in hair density (types III-IV).            
  • Girls:
    • Less severe
    • Preservation of the normal hairline without frontotemporal recession


  • Diagnosis is based on clinical presentation, hair loss pattern and family history.
  • Women with severe forms and other signs of hyperandrogenism may have underlying endocrinopathies and require hormonal evaluation.


  • Topical application of minoxidil is the currently recommended treatment:
    • Continuous use is necessary to preserve growth.
    • Re-growth takes 8-12 months.
    • Response rate for cosmetically acceptable hair growth is15-25%.




  • Recurrent and compulsivehair pulling that results in noticeable hair loss
  • Hair twisted around finger and pulled or rubbed until broken/extracted during inactive periods (e.g. while watching TV, in bed before falling asleep)


  • Most common form of childhood alopecia
  • Most commonly found in young children
  • Female to male ratio: 2.5 to 1
  • Associated with psychiatric disorders

Clinical Features

  • Insidious hair loss often starts in a single patch with irregular, angulated borders.
  • Affected areas have greatly reduced hair density but are not completely bald.
  • Short, stubby hair of varying lengths are present in the affected site.

Trichotillomania 1.jpg

  • Commonly involved sites are the frontoparietal scalp, eyebrows and eyelashes.


  • It is made by assessment of hair loss pattern and exclusion of other causes.
  • Regrowth of hair in a shaved patch confirms diagnosis
  • Biopsy of the affected area may be performed if diagnosis is doubtful.
  • Differential diagnosis: Alopecia area, tinea capitis, syphilis, traction alopecia


  • Evaluation should involve a careful social history that assesses sources of distress.
  • Best treatment modality is combination therapy,which includes psychopharmacology, psychotherapy and behavior modification techniques.
  • Mild shampoo and scalp lotion (hydrocortisone 1%) might relieve pruritis.




  • A traumatic hair loss in which certain hair styles, harsh chemicals and styling tools exert constant traction on the hair follicles, producing fractures of hair shafts with possible loss of follicles

Clinical Features                         

  • Results in patchy hair loss with scaling and perifollicular erythema
  • Presentations variable according to type of traction or trauma


  • History of hair care practices and physical examination of hair loss pattern is crucial to diagnosis.
  • Differential diagnosis: Alopecia areata, tinea capitis


  • Treatment involves discontinuing practices that exert traction on the hair.
  • Hair loss is reversible early on but may be permanent if traction is continued.
  • Recovery may take several months.




  • Non androgen-dependent excessive hair growth
  • Not associated with underlying endocrine abnormalities
  • Classified as congenital/acquired and generalized/localized
  • Can be associated with other abnormalities and as part of genetic syndromes

Congenital Hypertrichosis

  • May be transient, especially in premature infants, resolving by 6 months of age
  • Generalized:
    • Can be an isolated finding as in hypertrichosis lanuginosa: a rare hereditary syndrome in which the entire skin surface is covered by long, fine, soft, poorly pigmented lanugo hairs
    • Can occur as part of other genetic syndromes (e.g. Cornelia de Lange syndrome, gingival hyperplasia with hypertrichosis, familial porphyria cutanea tarda)
    • Can be a feature of fetal alcohol or fetal hydantoin syndromes
  • Circumscribed:
    • Differential diagnosis: nevoid hypertrichosis, congenital nevi, smooth muscle hamartoma, localized hypertrichosis in association with other abnormalities
    • Presents as one to several patches of excessive hair growth
    • Characterized by an excessive number of hair follicles
    • Usually persistent with few cases of spontaneous remission in literature
    • If located in midline, can be associated with nervous system abnormalities

Acquired Hypertrichosis

  • It is most commonly an adverse effect of medications particularly minoxidil, phenytoin, cyclosporine and oral contraceptives.
  • Each drug may result in a unique pattern of increased hair growth.
  • Discontinuation of medications leads to resolution of symptoms.


  • Long-term removal of unwanted hair represents a significant challenge.
  • Treatment depends on degree/distribution of hypertrichosis and the psychosocial needs of the child.
  • Various hair removal options are safe and effective:
    • Bleaching with hydrogen peroxide
    • Temporary hair removal: shaving, waxing, chemical depilation
    • Permanent hair removal: laser epilation, photoepilation, electrolysis




  • Excessive hair growth of terminal hair in a male sexual pattern
  • Occurs secondary to increased androgenic activity


  • Predominantly observed in adolescent females
  • Likely due to familial, ethnic and racial influences with hirsuteness being more common in Mediterranean females and uncommon in Asian females
  • Can be associated with endocrine disorders including PCOS, ovarian tumors, CAH, Cushing’s syndrome and exogenous steroid use
  • Idiopathic hirsutism with no other signs of virilization or endocrine abnormalities present in up to 15% of hirsute women

Clinical Features

  • Can be accompanied by other signs of androgen or cortisol excess (e.g. acne, acanthosis nigricans, striae, clitoral hypertrophy, deepening of the voice)
  • Coarse, curly and pigmented terminal hair observed in distinctly male patterns (e.g. beard, chest, areolae, linea alba, lower back, buttocks, inner thighs)


  • Ferriman-Gallwey scale can be used for diagnosis and classification of hirsutism:

A score of 0 (no hair growth) to 4 is given to rate hair growth in nine androgen-sensitive areas of the body. Scores are added to obtain a total hirsutism score, which is interpreted as:

  • <8: normal
  • 8-15: mild hirsutism
  • >15: moderate or severe hirsutism
  • Further work-up should be guided by history and physical examination and can include thyroid function tests, prolactin, FSH, LH, testosterone and 17-hydroxyprogesterone levels to screen for other endocrinopathies.


  • The decision of treatment must be guided by the severity of the condition and the level of psychological distress with careful consideration of the potential side effects of treatment modalities.
  • Treatment of underlying endocrinopathies and tumors result in significant improvement.
  • For women with idiopathic hirsutism, multiple treatment modalities are available:

Cosmetic Treatment

  • Bleaching with hydrogen peroxide
  • Temporary hair removal: shaving, waxing, chemical depilation
  • Permanent hair removal: laser epilation, photoepilation, electrolysis


  • Oral contraceptives
  • Antiandrogens (spironolactone, finasteride, flutamide)
  • Glucocorticoids
  • Insulin-lowering agents (e.g. metformin) suggested as alternative adjunct therapies
  • GnRH agonist (leuprolide) for severe, resistant cases
  • Continuous treatment for 6 months required for improvement


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