Androgenic alopecia

Androgenic alopecia is a hair loss caused by one of the following reasons:

• excess content of the male sex hormone dihydrotestosterone (DHT);
• increased sensitivity of hair follicles to DHT;
• Increased activity of the enzyme 5Alfa-reductase, which converts testosterone to DHT. By some estimates, androgenic alopecia accounts for up to 95% of all cases of baldness in men and women.

In men, androgenic alopecia usually starts in front of the hair growth line and advances to the vertex (although other variants are possible). In women, progressive thinning and thinning of hair is observed almost throughout the entire head, especially in the region of the vertex.

Still Hippocrates noticed that eunuchs do not grow bald. Later this same circumstance was noted by Aristotle. In the 1940's, James Hamilton wrote that the cause of baldness could be an excess of male sex hormones combined with a genetic predisposition.

[1], [2], [3], [4], [5], [6], [7]

The mechanism of development of androgenetic alopecia

Strictly speaking, it can not be said that sex hormones inhibit or enhance hair growth in general. The result of the action of androgens or estrogens on the hair will be determined by the presence of a special receptor on the surface of the cells of the hair follicle. The receptor resembles a button, and the hormone is a finger that presses this button. The result of pressing the button is predetermined by the mechanisms that are present in the follicle. You can press the same finger on the same buttons, and the result in one case will be an explosion at a military training ground, and in another - the launch of a spacecraft. The whole question is, what wires to these buttons are summed up. So, estrogens stimulate the growth of hair on the head and suppress the growth of hair on the face and body. Androgens stimulate the growth of the beard and mustache, the growth of hair in some parts of the body and can suppress the growth of hair on the head.

Of course, it's not so much in androgens as in what follicles in which areas are located. If there are follicles on the head that have DHT-dependent "buttons" for stopping growth, then hair loss will occur in response to an excess of androgens. If we transplant follicles from the area of the mustache or beard, then the excess of androgens, on the contrary, will cause hair growth on the head. By the way, one of the methods for combating alopecia in androgenic alopecia is precisely the transplantation of DHT-activating follicles into areas of baldness.

Women suffering from androgenic alopecia usually have other signs of hyperandrogenic syndrome - excessive growth of facial hair, acne, fat seborrhea. However, virilization, that is, the appearance of male features of the structure of the body, is rare. Almost always, both men and women suffering from androgenic alopecia have a normal or slightly elevated level of androgens in the blood. It is believed that the main cause of hair loss in androgenic alopecia is either an increase in the activity of 5A-reductase, or an increase in the sensitivity of receptors to DHT.

Hair is an important sexual sign, and they need to know whether they should grow on this part of the body. And it depends on who owns this body - a man or a woman. For example, follicles located in the chin area will react positively to DHT, since the beard is a masculine sign. But the excess of estrogens will cause these same follicles to suspend hair production. Hair follicles located on the scalp are stimulated with estrogens and suppressed (suppressed) by androgens (not for nothing long hair is primarily an ornament of women). If a follicle becomes too sensitive to androgens, this suppressive effect can become excessive.

DHT shows its suppressive effect in the phase of hair growth, and the hair prematurely enters the rest phase. Recall that each follicle can be in three different phases of the life cycle - anagen, catagen and telogen. Anagen is the period when the hair follicle produces hair. In the anagen stage, which lasts for several years, usually there are 85-90% of the hair follicles. Katagen - the period of degradation of the follicle. Hair growth stops, and the hair root becomes a characteristic bulb shape. This phase lasts for several weeks. In the telogenic phase, the hair separates from the root and slowly advances to the surface of the skin. In the telogen stage, approximately 10-15% of the hair is found. It is these hair that fall out when combing and washing your head. Normal hair loss is 70-80 pieces per day.

Diagnosis of androgenic alopecia

The diagnosis of androgenic alopecia in women can be made if:

• there are visible symptoms of androgenic alopecia - progressive thinning and diffuse hair loss, signs of hirsutism and acne;
• data of a microscopic examination show the presence of miniaturized follicles;
• when calculating the amount of hair in different growth phases, an imbalance between the hair follicles in the growth stage and in the resting stage is revealed;
• on the basis of microscopic research it was established that miniaturization of follicles and hair thinning does not affect the inferior occipital region. If there is every reason to talk about androgenetic alopecia and the diagnosis can be considered delivered, then the next problem is treatment.

[8], [9]

Treatment of androgenic alopecia

Treatment of androgenic alopecia includes:

• specific treatments for androgenic alopecia;
• nonspecific methods common to all types of alopecia. Specific methods include antiandrogen therapy, which is performed by both medicinal and alternative (alternative) agents. Anti-androgen therapy can reduce hair loss, but usually does not lead to restoration of the former density of hair. Stimulation of hair growth is carried out by methods common to all types of baldness.

A promising method is a selective effect on the activity of the enzyme 5Aulfa reductase, which converts testosterone to DHT in the skin. The method is attractive because the effects for which testosterone is responsible in the body (spermatogenesis, sexual behavior, distribution of muscle mass) remain unaffected. This is especially important for men who are horrified by the words "anti-androgen therapy."

Currently, one of the most effective drugs used to stimulate hair growth in androgenetic alopecia is minoxidil, which is marketed under the trade names "Regaine", "Rogaine", "Headway". We will talk more about it in the section on methods of treating alopecia, and now we will only say that minoxidil is the only drug that acts directly on the hair follicles, prolonging the phase of hair growth. Other methods of affecting the hair follicles include electrostimulation, massage, hypnotherapy and electrophoresis of biologically active substances.

Among antiandrogens, there are many medicines that can not be taken without consulting a doctor. Moreover, one of the most potent 5-alpha-reductase inhibitors - finasteride ("Propecia", "Proscar") is not suitable for the treatment of female androgenic alopecia, since it has a strong embryotoxic effect. For women, the drug "Diane-35", which is used as an oral contraceptive, is more acceptable. In addition to 5A-reductase inhibitors, androgen receptor blockers are used to treat androgenic alopecia in both men and women. If the blocker is strong enough, it can affect the libido, the size of the mammary glands (in men gynecomastia is observed), spermatogenesis and potency. The latter is the most frustrating for patients, therefore, along with antiandrogen, it is recommended to use yohimbe, arginine and other potentia stimulants.

Auxiliaries for treating alopecia include preparations based on plant extracts and natural compounds with antiandrogenic activity. Among them - oils rich in unsaturated fatty acids, extracts of fruits of dwarf palms and nettles, vitamin B6, zinc.

We must be prepared for the fact that the treatment of androgenetic alopecia is prolonged. The first results from the use of minoxidil and antiandrogen appear several months later. At the same time, the speed of hair loss slows down first, then you can wait for the gradual restoration of the density of the hairline.