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Androgenic Alopecia
Aka: Androgenic Alopecia, Androgenetic Alopecia, Male-patterned Baldness
- See Also
- Alopecia
- Definition
- Non-scarring androgen related Alopecia
- Epidemiology
- Most common type of Alopecia (esp. white men)
- Hereditary trait (positive Family History)
- Increasing Incidence with age
- Affects white men 30% at age 30, 40% at age 40, 50% at age 50 years
- Affects 38% of women over age 70 years
- Course
- Hair Loss onset between ages 12 to 40 years
- Hair Loss evident by age 50 in >50% of patients
- Pathophysiology
- Androgen exposure shortens Hair FollicleAnagen phase
- Men with increased androgen levels
- Women with increased 5a-reductase, androgen receptors
- Affected hair becomes shorter, finer, less pigmented
- Progresses with each successive cycle
- Related to higher Dihydrotestosterone (DHT) levels
- Metabolite of Testosterone
- Symptoms
- Gradual progression of Hair Loss
- Signs
- Men (M-Type distribution)
- Hair Loss affecting temples, frontal forehead and crown (vertex)
- Sides and back are spared
- Women
- Central and vertex scalp thinning
- Temples and frontal scalp are spared unlike the M-Type found in men
- Differential Diagnosis
- Hypothyroidism
- Iron Deficiency Anemia
- Malnutrition
- Grading: Rating of Hair Loss (Norwood and Hamilton Scale)
- Type I: Minimal hair line recession
- Type II: Symmetrical triangular Hair Loss over temples
- Type III: More Hair Loss at vertex and less at temple
- Type IV-V: Temple and vertex Hair Loss; some crown loss
- Type VI: Contiguous frontal, vertex, and crown baldness
- Type VII: Hair remains only over ears and occiput
- References
- Hamilton (1951) Ann NY Acad Dermatol 53:708-28
- Norwood (1975) South Med J 68(11):1359-65 [PubMed]
- Labs: Women with Androgenetic Alopecia
- Indications (Not required in most cases)
- Irregular Menses
- Sudden Hair Loss
- Hirsutism
- New onset Acne Vulgaris
- Infertility
- Lab tests
- Total Testosterone
- Free Testosterone
- Dehydroepiandrosterone sulfate (DHEA-S)
- Prolactin
- Management
- Precautions
- Medications used for Alopecia are continued indefinitely
- Hair Loss recurrs (back to baseline) with medication discontinuation
- If patients desire treatment, start medications at the first signs of baldness for best effect
- Medications are only modestly effective
- Medications for women
- Minoxidil (Rogaine) 2%
- Applied topically twice daily to dry scalp
- Risk of Hypertrichosis of the face
- Expect initial hair shedding on starting
- Retin-A may augment effect (experimental)
- Apply at different time of day
- Oral Contraceptives
- Less effective than Minoxidil
- Choose OCP with low Progestin Androgenic Activity
- Norgestimate (e.g. Ortho Tri-Cyclen)
- Norethindrone (e.g. Modicon)
- Spironolactone
- Variable efficacy - results in modest reduction in Hair Loss
- Dose: 100 to 200 mg orally daily in divided doses
- Flutamide (Eulexin)
- Dose: 250 mg orally daily
- Liver function abnormalities occur in up to one third of patients
- Finasteride is ineffective in women
- Medications for men
- Finasteride (Propecia)
- Dose: 1 mg orally daily
- Consider prescribing one quarter tablet daily of the 5 mg tablet (generic, cheap)
- Indicated for men only, and if topical Minoxidil ineffective
- Oral preparation for vertex or frontal balding
- Modifies serum PSA levels (upper limit of normal may be twice that of those not on Finasteride)
- Caution patients regarding risk of Suicidal Ideation, Sexual Dysfunction with Finasteride
- May help detect high grade Prostate Cancers earlier
- Thompson (2003) N Engl J Med 349:215-24 [PubMed]
- Minoxidil (Rogaine) 2% solution or 5% foam
- Most effective for vertex balding (than in frontal area), and effects are delayed 6-12 months
- Applied topically (1 ml) twice daily to dry scalp
- Expect initial hair shedding on starting
- Ketoconazole 2% Shampoo (Nizoral)
- Shampoo 2-4 times weekly
- Unknown efficacy and not FDA approved for Androgenetic Alopecia
- Pyrithione Zinc (1%)
- Shampoo 2-4 times weekly
- Unknown efficacy and not FDA approved for Androgenetic Alopecia
- Hair Transplant
- Looks better in photos
- Better in curly haired persons
- Laser devices (Restore Caps, HairMax Combs)
- Marginally effective at slowing Hair Loss and promoting Hair Growth
- Avoid ineffective or unproven measures
- Avoid topical oils
- Avoid oral supplements for Alopecia (Biotin, keratin, Saw Palmetto, zinc)
- References
- (2021) Presc Lett 28(11): 65
- Drake (1996) J Am Acad Dermatol 35:465-9 [PubMed]
- Phillips (2017) Am Fam Physician 96(6): 371-8 [PubMed]
- Scow (1999) Am Fam Physician, 59(8):2189-94 [PubMed]
- Springer (2003) Am Fam Physician 68(1):93-102 [PubMed]