Last month we discussed the Life Cycle of Hair in “Hair: Too Much or Too Little? ” and briefly touched on the Hormones which influence its growth. This month we shall look at the reverse condition of hair loss or Alopecia. This can have a devastating effect on a TG or TS who relies on their natural locks for appearances. Like most human tissues, hair recycles itself throughout life. Actively growing hair, Anagen phase, is followed by a brief Catagen phase, involution stage, and then by the Telogen or resting phase prior to being shed naturally. The number of hairs shed daily varies from 50 to 100 per day and is usually replaced by an equal number of new hairs. Normal scalp hair density decreases with age, andropause and menopause. The ratio of anagen to telogen hairs is approximately 9:1 or greater than 80%. For years it was thought that pattern balding in males was a sex linked recessive gene received from your mother’s father. It is now recognized that the inherited gene is an autosomal dominant from either parent with variable penetrance and expression. In the Caucasian race it appears to be the most common type of balding appearing in more than 50% of men and 40% of women, beyond age 40.
Androgenetic Alopecia, AGA, is an androgen-induced, progressive decrease in hair density. This may begin for some men in their twenties and is recognized by all as distinct pattern balding in men and women beginning in their forties. While normal Testosterone levels are maintained, hair sensitivity to the active Testosterone metabolite, Dihydrotestosterone, (DHT), is increased with age. In 1974 it was recognized that Testosterone was converted to DHT by the enzyme 5-alpha reductase, (5-AR), and later it was noted that there were 2 different 5-AR enzymes, Type I and Type II acting on different end organs. Type I acts on the scalp and predominates through adult life. While Type II appears at puberty in smaller amounts and influences hair on the face, chest, and genitalia. While androgens are not required for normal scalp hair growth, DHT appears briefly at birth, and is required for expression of beard, chest and suprapubic hair after puberty. Testosterone by itself can be sufficient for pubic and axillary hair growth. It then appears that increased DHT sensitivity is required for the development of AGA.
Approximately 50 years ago it was discovered that castration arrests balding at any age, but does not completely reverse it. Similarly the introduction of Estrogens with complete androgen suppression will improve scalp hair growth and arrest balding. In TSs it was found that the addition of the medicine Aldactone or Spironolactone to those receiving low dose Estrogens reduced facial hair and improved scalp hair density.
Telogen effluvium is the shedding of excessive hair in the telogen phase. It appears that stress, high fever, drug use and any body insult may increase the ratio of telogen:anagen hairs associated with a shortening of the anagen phase which normally can be up to 3 years. The hairs that fall out are shorter and appear broken with split ends. This is usually self limiting after four to six months and will take an equal time to return to normal. Other rare types like alopecia areata are associated with autoimmunce disorders and have large circular areas of balding. This may be treated by the application of topical or injectable corticosteroids. Fungal infections, hair straighteners and hair pulling into pony tails and corn rows have been associated with temporary alopecia.
Two new medications have reversed the hair loss of AGA. Topical Minoxidil, Rogaine 2% and Extra-strength Rogaine 5% have been found to be effective in men under 40 whose hair loss is of less than 10 years duration. A small amount applied daily will improve hair growth in over 50% of the men using it. The drug must be applied indefinitely or the areas will regress to their former appearance within months. The preparation is now packaged generically and can be purchased without prescription for half of its original cost.
Oral Finasteride (Propecia) is a 5-AR inhibitor and when taken as a daily 1 mg dose can reverse AGA at all ages. Four percent of men 18 to 40 taking Finasteride reported a decrease in libido and increased erectile dysfunction. Since this is the same drug used to decrease prostate size in larger 5 mg doses, it is easy to see how it can reduce ejaculates and serum Prostate Specific Antigen, PSA. This drug must also be taken indefinitely to keep your new hair.
Surgical Hair Transplantation has come of age. Using magnification, micro-grafts of individual or a few hair follicles, minigrafts, can be dissected from a strip of rear occipital hair and be reimplanted with a special needle to form a new aesthetically pleasing hairline. This may require 3 to 4 sittings under local anesthesia to reimplant thousands of new grafts where the “graft take rate” will be over 90% with long term growth. Plastic surgeons using skin expanders have stretched the crown and excised the common circular bald spot pulling the hair together. Over time this will reoccur as the circle of hair loss widens. Flaps of skin and hair have been swung from the sides to the middle, but sometimes the coarse side hair does not look natural in front. If you plan to undertake hair transplantation, ask to meet some of the surgeon’s patients so that you may view the quality of his work and ascertain his level of expertise.
Best of Luck in Your New Future,
Cerise Richards, M.D.