Androgenetic alopecia in men and women
Section snippets
Histopathology
The most striking feature seen on routine vertical sectioned scalp biopsies is the reduction in terminal anagen hairs, which normally penetrate through the dermis into the subcutis. These hairs are replaced by secondary psuedo-vellus hairs with residual angiofibrotic tracts called follicular streamers or stellae.13 There is an apparent reduction in the number of follicles; however, on horizontal sections of scalp biopsies, many pseudo-vellus hair follicles can be identified in the papillary
Pathogenesis
A model for the pathogenesis of androgenetic alopecia must account for the histological features mentioned above and in particular:
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The stepwise miniaturization of hair follicles,
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The alteration of the hair cycle dynamics with an increased telogen to anagen hair ratio,
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The systemic and local effects of androgens in promoting the condition, and
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The familial nature of the condition.
Morbidity of androgenetic alopecia
In recent years, considerable research has been done in an attempt to measure and quantify the morbidity of androgenetic alopecia in men and women. For most men, androgenetic alopecia is an unwanted and stressful event that diminishes their body image satisfaction.53 In random surveys asking men if they would mind going bald, only 8% of non-balding men stated it would concern them, while 50% with mild hair loss and 75% with moderate to severe hair loss were concerned by it.54 Their main
Management of androgenetic alopecia
In general, people concerned about their androgenetic alopecia have four options. They can do nothing, camouflage the hair loss either with topical agents or a wig, receive medical treatment, or undergo surgery.25
Without treatment, androgenetic alopecia is a progressive condition. Hairs vanish at a rate of approximately 5% per year,51 although there is marked individual variation in this, with some men taking 5 years to reach Hamilton VII and others taking 25 years or more. Nevertheless, for
Bogus treatments
Numerous over-the-counter products are promoted as cures for hair loss. Although their ingredients are generally safe for external use, they do not promote hair growth or prevent hair loss.67 In 1980, an advisory panel to the U.S. Food and Drug Administration evaluated a number of substances used in hair lotions and creams, found them to be ineffective, and subsequently proposed they be removed from the market.69 Those evaluated included amino acids, aminobenzoic acid, ascorbic acid, benzoic
Camouflage and wigs
Camouflage is the simplest, easiest, and cheapest way of dealing with mild androgenetic alopecia. Balding becomes most noticeable when the scalp can be seen through the hair. Camouflage treatments dye the scalp the same color as the hair, and give the illusion of thicker hair. Numerous brands are available in pressurized spray cans in a number of different colors, and they are often combined with a holding hair spray (and sunscreen). The hair is dried and styled before the dye that matches the
Medical treatment of androgenetic alopecia in men
Currently, there are two treatments approved by the U.S. Food and Drug Administration for the treatment of androgenetic alopecia in males—topical minoxidil and oral finasteride.
Minoxidil is available in both 2% and 5% formulations.70 Having observed hypertrichosis in men treated for hypertension with oral minoxidil,71 a topical formulation was developed for the treatment of androgenetic alopecia. The mechanism of action is unknown; however, it is thought that minoxidil sulfate, the active
Management of androgenetic alopecia in women
Topical minoxidil has been demonstrated to either arrest hair loss or induce mild to moderate hair regrowth in approximately 60% of women.85 It may be used alone or in combination with oral antiandrogen therapy.86 On cessation of treatment, there is a rapid correction with shedding of all minoxidil-dependent hairs.75
Oral antiandrogen therapy with cyproterone acetate, spironolactone, and flutamide are of benefit in arresting androgenetic alopecia in women.87 Most of the studies with these drugs
Scalp surgery
Scalp surgery using excision of bald scalp with or without tissue expansion, scalp flaps, and hair transplantation have been used in the treatment of advanced androgenetic alopecia for a number of years and are constantly undergoing revision and improvement. These have all been recently reviewed.101 While artificial fiber implantation has been used for androgenetic alopecia when donor fibers are unavailable, great caution is advised, as foreign body reactions and infections are potentially
Future developments
Second generation steroidal 5α reductase inhibitors, such as Gl-198745, W09704002, Turosteride, Mk-963, MK-434, Episteride, and MK-386, some of which also inhibit the type 1 isoenzyme, have been developed and are undergoing further investigation as are a variety of non-steroidal inhibitors such as zinc and saw palmetto.104, 105 Gl-198745, a combined type 1 and type 2 5α reductase blocker, has undergone extensive phase II investigation and has been shown to inhibit more than 90% of serum DHT.35
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