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Male-patterned BaldnessAka: Androgenetic Alopecia, Androgenic Alopecia

Definition
1. Non-scarring androgen related Alopecia
Epidemiology
1. Most common type of Alopecia
2. Hereditary trait
Course
1. Hair Loss onset between ages 12 to 40 years
2. Hair Loss evident by age 50 in >50% of patients
Pathophysiology
1. Androgen exposure shortens Hair Follicle Anagen 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
Symptoms
1. Gradual progression of Hair Loss
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
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
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
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
2. Medications for men
  1. Finasteride (Propecia)
    1. Indicated for men only
    2. Oral preparation for vertex or frontal balding
    3. Longterm use risks high grade Prostate Cancer
      1. Thompson (2003) N Engl J Med 349:215
  2. Minoxidil (Rogaine 5%)
    1. Most effective for vertex balding
    2. Applied topically twice daily to dry scalp
3. Hair Transplant
  1. Looks better in photos
  2. Better in curly haired persons
References

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This page was written by Scott Moses, MD. This page was last revised before 5/10/08, prior to consistent tracking of revision date. This page was last published on 5/10/2008. Please send comments and questions to the editor. Contact information may be found on the page About the Family Practice Notebook. These pages are best viewed with Microsoft Internet Explorer 6.0.