• Alopecia: Absence of hair from areas where it normally exists:
    • Anagen phase: Growing hairs
    • Telogen phase: Dead, “resting” hairs
  • Classified as scarring (cicatricial) or nonscarring
  • Androgenetic alopecia (male- or female-pattern hair loss): Hair loss and miniaturization of hair follicles:
    • In men: Frontal recession, then vertex affected; over time, only lateral and occipital hair are left (Norwood Hamilton Classification type I–VII)
    • In women: Thinning across the crown, with frontal hair later affected (Ludwig Classification, grade I–III)
  • Alopecia areata: Patchy, nonscarring hair loss:
    • Alopecia totalis: Hair loss of the entire scalp
    • Alopecia universalis: Loss of all body hair
  • Telogen effluvium: Diffuse hair loss that (usually) has temporarily decreased hair density but not complete baldness:
    • Abnormal hair cycling leads to excessive loss of hairs in telogen phase.
    • Usually occurs 3 months after the trigger occurs
  • Anagen effluvium: Diffuse shedding of hairs, including growing hairs, that may progress to complete baldness:
    • Growth arrest of hair in anagen phase and sheds
    • Begins days to weeks after inciting incident
  • Cicatricial alopecia (scarring alopecia): Slick, smooth scalp without evidence of follicular openings
  • Traction alopecia: Patchy, initially nonscarring hair loss usually due to physical stressors on hair:
    • Trichotillomania: Hair loss due to the person pulling hair out
  • Tinea capitis: Patches of hair broken off close to the scalp sometimes with inflammation, caused by fungal infection

Pediatric Considerations
Tinea capitis is more common among children.

Pregnancy Considerations
Telogen gravidarum: Hair loss 2–4 months after childbirth


  • Age: Androgenic alopecia: May begin after puberty and increases in prevalence over time
  • Predominant sex: Male > Female

Alopecia areata: 0.1–0.2% incidence in all races

  • Androgenic alopecia:
    • Men: 15% of adolescent males, 50% of white men >50
    • Women: 6–12% <30 with up to 50% lifetime prevalence
  • Alopecia areata:
    • 1.7% of US population

Risk Factors

  • Physiologic or psychologic stress
  • Pregnancy
  • Poor nutrition
  • Use of certain medications/chemotherapy
  • Tight living quarters
  • Sharing hair products/supplies
  • Family history of early hair loss
  • Polygenic inheritance of androgenic alopecia

General Prevention

  • For traction alopecia: Minimize braids, coloring, bleaching, waving of hair, or hair styles that pull hair.
  • For tinea capitis: Avoid sharing hats, combs, hairbrushes, hair ornaments, and pillows.


  • All hair follicles pass through anagen and telogen phases.
  • When many are in the telogen phase at one time, the hair loss becomes noticeable.
  • Activity of hair follicles may diminish due to trauma, medications, or disease.


  • Androgenic alopecia:
    • Genetically predisposed
    • Polycystic ovarian syndrome
    • Adrenal hyperplasia
    • Pituitary hyperplasia
    • Drugs (testosterone, progesterone, danazol, adrenocorticosteroids, anabolic steroids)
  • Alopecia areata: Autoimmune processes like thyroiditis
  • Telogen effluvium:
    • In most cases, no specific etiology is found.
    • Postpartum
    • Adding or changing medications (oral contraceptives, anticoagulants, anticonvulsants, SSRIs, retinoids, β-blockers, ACE inhibitors, colchicine, cholesterol-lowering medications, cimetidine, levodopa, bromocriptine, chemotherapeutic agents, interferon, others)
    • Stress: Physical (fever, trauma, surgery) or psychologic
    • Chronic illness (systemic lupus erythematosus [SLE], syphilis, systemic amyloidosis, hepatic failure, chronic renal failure, inflammatory bowel disease, dermatomyositis, HIV, lymphoproliferative disorders)
    • Hormonal (hypo-/hyperthyroid, pituitary dysfunction)
    • Malnutrition (iron deficiency, zinc deficiency, caloric restriction/eating disorder)
    • Malabsorption (celiac disease, pancreatic disease)
    • Inflammatory skin disorders (psoriasis, seborrheic dermatitis, allergic contact dermatitis)
  • Anagen effluvium:
    • Chemotherapy is most common trigger
    • Radiation to the area
    • Drugs (chemotherapeutic agents, allopurinol, colchicine)
    • Poisoning (mercury, thallium, bismuth, arsenic, gold, boric acid)
    • Severe protein malnutrition
  • Cicatricial alopecia:
    • Physical agents/trauma (burns, freezing, radiation)
    • Congenital (aplasia cutis congenital, Conradi-Hunermann chondrodysplasia punctata)
    • Lymphocyctic (cutaneous discoid lupus erythematous, central centrifugal cicatricial alopecia, lichen planopilaris)
    • Neutrophilic (folliculitis decalvans, dissecting folliculitis)
    • Acne keloidosis
    • Infection (zoster, kerion, folliculitis)
    • Metastatic or primary neoplasm
  • Traction alopecia:
    • Trichotillomania (direct self-pulling of the hair, obsessive-compulsive behavior)
    • Tight rollers or braids
  • Tinea capitis (Microsporum, Trichophyton)

Commonly Associated Conditions

Alopecia areata:

  • Down syndrome
  • Autoimmune thyroiditis
  • Vitiligo
  • Diabetes



  • Duration of hair loss
  • Episodic or continuous
  • Pattern of hair loss
  • Medications
  • Chronic disease, recent illness, surgeries, pregnancy
  • Changes in health/medication in past 2–3 months
  • Psychological stress
  • Dietary history and weight changes
  • Menstrual history
  • Family history of hair loss or autoimmune disorders
  • Radiation or exposure to heavy metals
  • Pruritus (in tinea capitis)

Physical Exam

  • Pattern of hair loss:
    • Is hair loss generalized or local?
    • If local, is it symmetrical at the vertex and/or the hairline at the forehead?
  • Scalp scaling, inflammation (in tinea capitis)
  • Changes in the hair:
    • Hair-pull test: Pinch 25–50 hairs between thumb and forefinger, and exert slow, gentle traction while sliding fingers up:
      • Normal: 1–2 dislodge
      • Abnormal: ≥6 hairs dislodged (in effluvium, alopecia areata)
    • Broken hairs (tinea capitis, traction alopecia)
    • Broken-off hair at the borders of the patch that are easily removable (in alopecia areata)
    • Hair loss in circular pattern (in alopecia areata, tinea capitis)
  • Clinical signs of thyroid disease, lupus, or other diseases
  • Clinical signs of virilization: Acne, hirsutism, acanthosis nigrans, truncal obesity (in androgenic alopecia)

Diagnostic Tests and Interpretation

  • Thyroid-stimulating hormone (TSH)
  • CBC (anemia); serum ferritin if anemic
  • Consider comprehensive metabolic panel (liver and renal disease)
  • Consider free testosterone and dehydroepiandrosterone sulfate (hyperandrogenism)
  • Consider serum zinc (deficiency)
  • Consider rapid plasma reagin test (syphilis)
  • Consider prolactin (pituitary hyperplasia)
  • Consider antinuclear antibody (ANA) (autoimmune disorders)
Diagnostic Procedures/Surgery
  • Light hair-pull test: Pull on 25–50 hairs; ≥6 hairs dislodged is consistent with shedding (effluvium, alopecia areata).
  • Direct microscopic exam of the hair shaft (video dermatoscopy):
    • Anagen hairs: Elongated and possibly pigmented bulb with gelatinous root sheath
    • Exclamation point hairs: At periphery of lesion and has club-shaped root with thinner proximal shaft that distally becomes normal in size (alopecia areata)
  • Daily hair counts: Collect hair in dated envelopes for 2 weeks, in morning:
    • >100 hairs per day is consistent with effluvium
  • Ultraviolet light fluorescence and potassium hydroxide prep (to rule out tinea capitis)

Pathological Findings
Scalp biopsy with routine microscopy will aid in the diagnosis if unsure.

Differential Diagnosis

Search for type of alopecia and then for reversible causes.


Medication (Drugs)

  • Androgenic alopecia: Treatment must be continued indefinitely. Magnitude of effect is variable, and not all benefit:
    • Minoxidil (Rogaine) 2% topical solution (1 mL b.i.d.) for women, 5% topical solution (1 mL b.i.d.) or foam (daily) for men (1)[A].
    • Finasteride (Propecia), 1 mg/d for men (1)[A]
    • Spironolactone (Aldactone) 100–200 mg/d in hyperandrogenic women (off-label) (1)[C]: Diuretic with antiandrogen actions
    • Oral contraception pills with low levels of androgenic affect in women (Yasmin, Ortho-TriCyclen, Ortho-Cyclen, Ortho-Evra, Mircette) (off-label) (2)[C]
    • Ketoconazole 2% shampoo with minoxidil 2% (1)[C]
  • Alopecia areata:
    • Intralesional steroids: Triamcinolone 2.5–10 mg/mL (3,4)[C]:
      • First line in adults if <50% scalp involved
      • Repeat every 4–6 weeks; if no improvement in 6 months, stop treatment
      • 0.5-inch, 30-gauge needle and inject 0.1 mL at each point at 1-cm intervals
    • If >50% scalp involved, refer to dermatologist (3)
    • Children: Topical mid-potent corticosteroids (3)[C]
    • Systemic glucocorticoids: May induce regrowth, but alopecia recurs after cessation of medication and risks may outweigh benefits for long-term use (3,4)[C]
  • Telogen effluvium: Remove offending medication (5)[C]. Process is usually reversible.
  • Tinea capitis: See appropriate section on tinea.
  • Traction alopecia: Avoid styling techniques. SSRI or psychological support for trichotillomania.
  • Side effects/precautions:
    • Topical minoxidil:
      • Irritant dermatitis (more likely with 5% than 2%) or contact allergic dermatitis
      • Hypertrichosis
      • Exacerbation of angina (rare)
    • Intralesional steroids: Local burning, stinging, pruritus, skin atrophy
    • Spironolactone:
      • Menstrual cycle abnormalities
      • Postural hypotension
      • Electrolyte imbalance (hyperkalemia)
    • Finasteride:
      • Caution in known liver disease
      • Sexual side effects
      • Monitor prostate-specific antigen (PSA): Will decrease PSA level by 50%

Pregnancy Considerations
Finasteride not indicated for use in women; pregnancy Category X. Women should not handle crushed or broken pills during childbearing years.

Additional Treatment

General Measures
  • Trial off offending medication may resolve issue. If unsure which medication, may readminister if patient is willing.
  • Traction alopecia:
    • Only with discontinuation of the hair pulling will the disorder resolve.
    • Psychological or psychiatric intervention may be necessary.
    • Successful therapeutic approaches have included medications, behavior modification, and hypnosis.

Complementary and Alternative Therapies

  • Many herbal medications are available but lacking research at this time.
  • Volumizing shampoos can help remaining hair look fuller.
  • Androgenic alopecia: Low-energy laser light: HairMax LaserComb (1)[C]: Safe alternative, but lacking research

Surgery/Other Procedures

  • Hair transplantation
  • Wigs, hairpieces, extensions
  • Androgenic alopecia: Surgical (hair transplantation, scalp reduction, transposition flap, and soft tissue expansion). Medical tattooing of eyebrows
  • Cicatricial alopecia: The only effective treatment is surgical (graft transplantation, flap transplantation, or excision of the scarred area) (6).

Ongoing Care


If nutritional deficit noted, supplementation may be necessary.

Patient Education

National Alopecia Areata Foundation:


  • Androgenic alopecia: Prognosis depends on treatment
  • Alopecia areata: Usually regrows within 1 year even without treatment. Recurrence common. 10% have severe, chronic form.
  • Telogen effluvium: Maximum shedding 3 months after the inciting event and recovery following correction of the cause. Usually subsides in 3–6 months but takes 12–18 months for cosmetically significant regrowth. Rarely, permanent baldness. Chronic effluvium is uncommon.
  • Anagen effluvium: Shedding begins days to a few weeks after the inciting event, with recovery following correction of the cause. Rarely, permanent baldness
  • Cicatricial alopecia: Hair follicles permanently damaged
  • Traction alopecia: Depends on behavior modification
  • Tinea capitis: Usually complete recovery

Additional Reading

See Also



  • 704.00 Alopecia, unspecified
  • 704.01 Alopecia areata
  • 704.09 Other alopecia
  • 704.02 Telogen effluvium


  • L65.9 Nonscarring hair loss, unspecified
  • L64.9 Androgenic alopecia, unspecified
  • L63.9 Alopecia areata, unspecified
  • L63.0 Alopecia (capitis) totalis
  • L63.1 Alopecia universalis
  • L65.0 Telogen effluvium


  • 56317004 Alopecia (disorder)
  • 87872006 Male pattern alopecia (disorder)
  • 68225006 Alopecia areata (disorder)
  • 19754005 Alopecia totalis
  • 238725004 non-scarring alopecia (disorder)
  • 39479004 Telogen effluvium (disorder)
  • 400088006 Scarring alopecia
  • 86166000 Alopecia universalis (disorder)

Clinical Pearls

  • History and physical will usually determine type of alopecia.
  • Treatment of underlying medical condition or removal of triggering medication in many types of alopecia will reinstate hair growth without the need of further interventions.
  • Educating the patient about the nature of the condition and expectations is key to care.
  • Alopecia can affect the psychological condition of the patient, and it maybe necessary to address this in any type of hair loss.


Alexei DeCastro, MD, FAAFP


Figure 10-4

Alopecia areata. Note black, flecklike "exclamation mark" hairs at the periphery.
Figure 10-5

Alopecia areata. This man's alopecia areata is limited to his beard.
Figure 10-6

Alopecia areata (alopecia universalis). This patient has lost most of her eyebrows, which she colors in with an eyebrow pencil. She also lacks eyelashes, pubic hair, axillary hair, and hair on her extremities.
Figure 10-7

Alopecia areata (regrowing hair). In this patient with alopecia areata, clusters of hair regrew after intralesional triamcinolone acetonide injections. Some of the regrown hairs are white (vitiliginous).
Figure 10-8

Trichotillomania. This condition is seen most often in young girls. Hairs tend to be broken at different lengths. The areas of alopecia are not completely devoid of hair.
Figure 10-11

Traction alopecia. This woman's alopecia is the result of the use of tight curlers: Note the symmetric loss of hair in a frontotemporal distribution. Also note the "relaxed" curl that was chemically straightened.
Figure 10-12

Traction alopecia. Note the fringe of residual hairs at the distal margin of alopecia. These hairs were too short to be "grabbed" by the hair curlers.


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  2. Goh C, Zippin JH. Androgenetic alopecia: Diagnosis and treatment with a focus on recent genetic implications. J Drugs Dermatol. 2009;8:185–192.  [PMID:19213237]
  3. Alkhalifah A, Alsantali A, Wang E, et al. Alopecia areata update: Part II. Treatment. J Am Acad Dermatol. 2010;62.
  4. Mounsey AL, Reed SW. Diagnosing and treating hair loss. Am Fam Physician. 2009;80:356–362.  [PMID:19678603]
  5. Harrison S, Bergfeld W. Diffuse hair loss: Its triggers and management. Cleve Clin J Med. 2009;76:361–367.  [PMID:19487557]
  6. Rongioletti F, Christana K. Cicatricial (scarring) alopecias: An overview of pathogenesis, classification, diagnosis, and treatment. Am J Clin Dermatol. 2012;13(4):247–260.  [PMID:22494477]

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