Dr. Sam Gershenbaum - Aventura Cosmetic Surgery

Male Follicle Loss
(Androgenetic Alopecia)

An estimated 35 million men in the country are affected by androgenetic alopecia. “Andro” refers to the androgens (testosterone, dihydrotestosterone) necessary to produce male-pattern loss (MPHL). “Genetic” refers to the inherited gene necessary for MPHL to occur. This gene may be inherited from either the mother's or the father’s side. MPHL may begin at any time after puberty when the blood levels of androgens rise. Temporal recession is the first change seen in approximately 90 percent of males, including those whom are not destined to progress to further levels of baldness.

Hamilton, and later Norwood, have classified patterns of male pattern hair loss (MPHL). There is no way to predict what pattern of baldness a young man will eventually assume. Those who begin to go bald in their 20s will generally have the most loos of follicles.

Overall, however, the onset, rate, and severity of the depletion are unpredictable. If androgens (testosterone, dihydrotestosterone) are present in normal amounts, and the gene for thinning follicles is present, male baldness will occur.

Testosterone is naturally converted to dihydrotestosterone (DHT) by the enzyme 5-alpha-reductase. It is the DHT, along with the gene for baldness, that ultimately results in male baldness. Finasteride (Propecia) acts by blocking this enzyme and decreasing the amount of DHT.

Follicles sensitive to DHT interact on a molecular level altering the production of the proteins or keratins, which ultimately causes progressive miniaturization and loss. The growth cycle is affected in that the percentage of hairs in the growth phase (anagen) and the duration of the growth phase diminish, resulting in shorter and finer hairs. As more hairs remain in the resting phase (telogen), they are subject to loss with the daily trauma of combing and washing. The follicle shafts in MPHL become progressively miniaturized ... smaller in diameter and length as well as gradually losing pigment and becoming lighter in color. This miniaturization process is generally first noted as thinning, which may progress to complete loss of follicles over time in the patterned area.