Main causes of hair loss

Ksenia Kisimes , leading dermatologist, cosmetologist, BOGOMOLETS CLINIC, speaker, member of EADV, UHPS, Ukrainian Association of Dermatovenerologists and Cosmetologists

The hair follicle and hair go through several stages in development: the growth period is anagen, the resting period is telogen, the period of transition from one stage to another is catagen. At the catagen stage, atrophy of the hair papilla begins, as a result of which the cells of the hair follicle, limited in nutrition, stop dividing and undergo keratinization. It is believed that the first hair cycle begins with the catagen stage (lasts several weeks), followed by a short telogen stage (lasts several months), which passes into the developmental stage - anagen. The anagen phase has six periods of development and lasts about 3-6 years. Mechanical removal of hair in the telogen stage always leads to the onset of the anagen stage, the hair begins to grow again. Therefore, laser hair removal does not provide quick and visible results. Hair that remains in the brush or falls out during the day is usually telogen effluvium. Previous research has shown that anagen hair may not be able to replace telogen hair in androgenetic alopecia . Using a phototrichogram, a new phenomenon was discovered: an empty hair follicle after teloptosis, which means “empty.” During ketogen, the hair follicle is physiologically at rest, but the duration of this phase and the frequency of its occurrence were greater in patients with androgenetic alopecia. In addition to the classic hair growth cycle, the hair follicle can develop according to a different pattern, when the telogen phase is not accompanied by the simultaneous onset of anagen, but ends with teloptosis, leaving an empty hair follicle.

Of course, the risk of hair loss is determined by a wide range of factors, among which genetic factors come first, and stress factors come second. The study identified risk factors for hair loss by examining about 100 pairs of female identical twins (average age 50 years). Twins have completely identical genomes, which made it possible to identify non-genetic ones. In the first place among non-genetic factors are stress caused by life situations, loneliness or divorce, everyday problems and deficits.

What is the frequency of the most common diagnoses of alopecia among trichologists? Androgenetic alopecia – 70-80%, telogen effluvium – about 10%, alopecia areata – about 10%, scarring alopecia – about 5%.

What are the main causes of hair loss? Physiological reasons: in the postpartum period, postpubertal hair loss associated with changes in body weight, height, early adrenarche, polycystic ovary syndrome, congenital dysfunction of the adrenal cortex. Metabolic causes: medicinal cause caused by narcotic drugs, possibly after vaccination, surgery and trauma, hyperthermia (39-40 °C), caused by stress or endocrine diseases. Alopecia caused by deficiency conditions: malabsorption syndrome, various types of anemia, enteropathic acrodermatitis.

Most of the population of Ukraine lives above the 42nd parallel, so there is a lack of sufficient levels of insolation throughout the year, which provokes a serious deficiency of vitamin D. Studies were conducted at the University of Tokyo with the participation of laboratory animals. Vitamin D was added to the medium containing follicles grown from stem cells. The result was an increase in the number and quality of the resulting follicles, which allowed scientists to suggest that alopecia can be overcome with the help of vitamin D, which can not only improve the condition of existing follicles, but also stimulate the formation new.

A study in the USA showed that the processes of development of old hair follicles and the birth of new ones are influenced mainly not by vitamin D itself, but by its receptors located in the skin. They noticeably revive when this vitamin enters the skin. It was recently discovered that such receptors can be activated using discovered molecules called LEF1 and MED. Vitamin D may be a protective factor for a number of autoimmune diseases, including alopecia areata. (The Role of Vitamin D Receptor Mutations in the Development of Alopecia Peter J. Malloy and David Feldman Molecular and Cellular Endocrinology)

Relatively recently, the immunomodulatory properties of vitamin D have been described.

Vitamin D interacts with monocytes, macrophages, dendritic cells, T- and B-lymphocytes, influencing both innate and acquired immunity. In addition, immune cells secrete enzymes that allow local synthesis of the active form of vitamin D from precursors. A decrease in the content of this vitamin in the body leads to an increased risk of infectious and autoimmune diseases: tuberculosis, systemic lupus erythematosus, rheumatoid arthritis, diabetes, multiple sclerosis (Holik MF. 2007, Pierrot-Deseilligny C. 2009, Ascherio A, Munger KL, Simon KC. 2010)

Hair follicles have receptors for vitamin D. Current evidence suggests that vitamin D receptors are necessary for the adequate functioning of hair follicles. In the meantime, scientists recommend that people suffering from alopecia include foods rich in vitamin D (for example, fatty fish) in their diet, and also spend more time in the sun.

Read the continuation of the article in the next material.