II. Definition

  1. Non-scarring androgen related Alopecia

III. Epidemiology

  1. Most common type of Alopecia
  2. Hereditary trait

IV. Course

  1. Hair Loss onset between ages 12 to 40 years
  2. Hair Loss evident by age 50 in >50% of patients

V. Pathophysiology

  1. Androgen exposure shortens Hair FollicleAnagen phase
    1. Men with increased androgen levels
    2. Women with increased 5a-reductase, androgen receptors
  2. Affected hair becomes shorter, finer, less pigmented
  3. Progresses with each successive cycle
  4. Related to higher Dihydrotestosterone (DHT) levels
    1. Metabolite of testosterone

VI. Symptoms

  1. Gradual progression of Hair Loss

VII. Signs

  1. Men
    1. Hair Loss affecting temples and crown
    2. Sides and back are spared
  2. Women
    1. Central and frontal scalp thinning
    2. Temples are spared unlike the M-Type found in men

VIII. Class: Rating of Hair Loss (Norwood and Hamilton Scale)

  1. Type I: Minimal hair line recession
  2. Type II: Symmetrical triangular Hair Loss over temples
  3. Type III: More Hair Loss at vertex and less at temple
  4. Type IV-V: Temple and vertex Hair Loss; some crown loss
  5. Type VI: Contiguous frontal, vertex, and crown baldness
  6. Type VII: Hair remains only over ears and occiput
  7. References
    1. Hamilton (1951) Ann NY Acad Dermatol 53:708-28
    2. Norwood (1975) South Med J 68(11):1359-65 [PubMed]

IX. Labs: Women with Androgenetic Alopecia

  1. Indications (Not required in most cases)
    1. Irregular Menses
    2. Sudden Hair Loss
    3. Hirsutism
    4. New onset Acne Vulgaris
    5. Infertility
  2. Lab tests
    1. Total Testosterone
    2. Free Testosterone
    3. Dehydroepiandrosterone sulfate (DHEA-S)
    4. Prolactin

X. Management

  1. Medications for women
    1. Minoxidil (Rogaine) 2%
      1. Applied topically twice daily to dry scalp
      2. Risk of Hypertrichosis of the face
      3. Retin-A may augment effect (experimental)
        1. Apply at different time of day
    2. Oral Contraceptives
      1. Less effective than Minoxidil
      2. Choose OCP with low Progestin Androgenic Activity
        1. Norgestimate (e.g. Ortho Tri-Cyclen)
        2. Norethindrone (e.g. Modicon)
    3. Spironolactone
      1. Variable efficacy - results in modest reduction in Hair Loss
      2. Dose: 100 to 200 mg orally daily in divided doses
    4. Flutamide (Eulexin)
      1. Dose: 250 mg orally daily
      2. Liver function abnormalities occur in up to one third of patients
  2. Medications for men
    1. Finasteride (Propecia)
      1. Dose: 1 mg daily
        1. Consider prescribing one quarter tablet daily of the 5 mg tablet (generic, cheap)
      2. Indicated for men only
      3. Oral preparation for vertex or frontal balding
      4. Modifies serum PSA levels (upper limit of normal may be twice that of those not on Finasteride)
      5. May help detect high grade Prostate Cancers earlier
        1. Thompson (2003) N Engl J Med 349:215-24 [PubMed]
    2. Minoxidil (Rogaine 5%)
      1. Most effective for vertex balding
      2. Applied topically (1 ml) twice daily to dry scalp
    3. Ketoconazole 2% Shampoo (Nizoral)
      1. Shampoo 2-4 times weekly
    4. Pyrithione Zinc (1%)
      1. Shampoo 2-4 times weekly
  3. Hair Transplant
    1. Looks better in photos
    2. Better in curly haired persons

Images: Related links to external sites (from Bing)

Related Studies (from Trip Database) Open in New Window

Ontology: Androgenetic Alopecia (C0162311)

Concepts Disease or Syndrome (T047)
MSH D000505
ICD10 L64 , L64.9
SnomedCT 238726003, 333111000009102, 87872006, 201144006
English Alopecia, Androgenetic, Alopecia, Male Pattern, Male Pattern Baldness, Male Pattern Alopecia, Androgenic alopecia, unspecified, ANDROGENETIC ALOPECIA, AGA, MPB, Androgenetic Alopecia, ALOPECIA ANDROGENET, ANDROGENET ALOPECIA, BALDNESS, MALE PATTERN, male pattern baldness (physical finding), male pattern baldness, male-pattern baldness, alopecia androgenic, male pattern alopecia, baldness male pattern, alopecia androgenetic, androgenic alopecia, androgenetic alopecia, pattern baldness, Baldness, Male Pattern, androgenic alopecia (diagnosis), Pattern Baldness, Androgenic Alopecia, Female Pattern Baldness, Androgenic alopecia (disorder), Atrophic follicular dysplasia (finding), Atrophic follicular dysplasia, Male pattern alopecia, Common baldness, Hereditary alopecia, Alopecia hereditaria, Androgenetic alopecia, Male pattern baldness, Pattern baldness, Androgenic alopecia, Male pattern alopecia (disorder), Alopecia hereditaria (disorder), baldness; male-pattern, alopecia; androgenic, androgenic; alopecia
French Alopécie androgénétique, Alopécie androgénétique de l'homme, Alopécie androgénique, Alopécie de type masculin, Calvitie de type masculin, Alopécie androgénogénétique, Calvitie hippocratique
German Alopezie, androgenetische, Male-pattern Alopezie, androgene Alopezie, Alopecia androgenetica, nicht naeher bezeichnet, Alopecia androgenetica, Alopezie, männlicher Typ, Glatzenbildung vom männlichen Typ
Spanish Calvicie de tipo masculino, Alopecia androgénica, Alopecia androgénetica, alopecia andrógena, alopecia de distribución masculina (trastorno), alopecia de distribución masculina, alopecia hereditaria (trastorno), alopecia hereditaria, calvicie común, Alopecia Androgenética, Calvicie Masculina
Italian Calvizie maschile con distribuzione, Alopecia androgenica, Alopecia maschile, Calvizie maschile, Alopecia androgenetica
Dutch mannelijk kaalheidspatroon, androgenetische alopecie, androgene alopecie, alopecia; androgeen, androgeen; alopecia, kaalheid; mannelijk patroon, Alopecia androgenetica, niet gespecificeerd, 'Male pattern'-kaalheid, Alopecia androgenetica
Portuguese Alopécia androgenética masculina, Alopécia androgénica, Alopécia androgenética, Alopecia Androgênica, Calvície Padrão Masculino
Japanese ダンセイガタダツモウショウ, アンドロゲンセイダツモウショウ, アンドロゲン性脱毛症, 男性型脱毛症
Czech Plešatost mužského typu, Androgenetická alopecie, Androgenní alopecie, androgenetická alopecie
Korean 안드로젠성 탈모증, 상세불명의 안드로젠성 탈모증
Hungarian Férfias jellegű kopaszság, Androgenetikus alopecia, Androgén alopecia
Norwegian Alopesi av mannlig type, Skallethet av mannlig type, Androgen alopesi, Alopecia androgenica