Focal alopecia

Alopecia areata is a rather rare disease, which nevertheless attracts the attention of many scientists. It is interesting because hair loss, starting in the midst of complete well-being, suddenly stops. It can continue for a long time and lead to complete baldness in certain areas of the head or even the body, or it can stop quite quickly.

Alopecia areata usually begins with a small patch of baldness that may progress to complete hair loss on the scalp (alopecia totalis) or the entire body (alopecia universalis). Extensive hair loss occurs in only a small proportion of people affected by alopecia areata, approximately 7%, although in the recent past this proportion was 30%.

There are three types of hair at the edge of the bald patch - cone-shaped, club-shaped and exclamation mark-shaped. The hair that is regenerating is thin and unpigmented, and only later does it acquire its normal color and texture. Hair regeneration may occur in one area of the scalp, while hair loss may continue in another area.

According to various estimates, from 7 to 66% (on average 25%) of people suffering from focal alopecia also have deviations in nail formation. Nail dystrophy can range from mild (roughness, chipping) to extreme.

The causes of the various manifestations of the disease have not been studied well enough. For a long time, it was questionable whether the different forms of hair loss were the same disease. There are apparently some differences in the onset and development of the disease that scientists are still unaware of. Intensive research is being conducted in this area, and some things have already been clarified.

Who is susceptible to alopecia areata?

Demographic studies have shown that 0.05–0.1% of the population suffers from alopecia at least once. In England, there are 30–60 thousand people with focal alopecia, in America – 112–224 thousand and worldwide – 2.25–4.5 million people. The first signs of alopecia appear in most people at the age of 15–25.

It has been shown that in 10-25% of cases the disease has a familial origin. Most people suffering from focal alopecia are healthy, with the exception of cases of alopecia caused by Down syndrome, Addison's disease, thyroid disorders, vitiligo and a number of other diseases.

There are two schools of thought regarding the incidence of alopecia areata in men and women: either the disease affects men and women equally (1:1) or it affects women more (2:1). In many autoimmune diseases, women are affected even more (10:1 in systemic lupus erythematosus).

It is believed that this is due to differences in hormonal levels between men and women.

Humoral and cellular immunity of women is on average more active than that of men, it resists bacterial and viral infections better. But such highly mobile immunity is more susceptible to the development of autoimmune processes. It is known that many hormones, including sex steroids, adrenaline, glucocorticoids, thymus hormones and prolactin, affect the activity of lymphocytes. But still, the most powerful hormone affecting the immune system is estrogen - the female sex hormone.

Treatment strategy for alopecia areata

Hair is capable of restoration even after many years of illness. A significant number of patients, especially those with a mild form of the disease, may experience spontaneous hair restoration. With proper treatment, remission may occur even in severe cases. Of course, there are incurable forms, and cases where hair growth is restored only with constant treatment, and when it is stopped, the hair falls out again within a few days.

In some patients, despite treatment, the disease relapses. Unfortunately, there are no universal remedies or methods for treating focal alopecia. Here are some useful practical tips:

• To maximize the cosmetic effect of treatment for severe, noticeable alopecia areata, it is necessary to treat the entire scalp, not just the obviously affected areas;
• You should not expect any positive changes earlier than in three months;
• Cosmetic hair regrowth may take a year or more, with ongoing treatment increasing the likelihood of permanent hair growth, but individual bald spots may appear and disappear;
• In patients with periodic hair loss, the treatment effect is improved by prophylactic administration of antihistamines;
• Hair growth is also promoted by preventive intake of multivitamins; in severe cases of the disease, injections of B vitamins are recommended;
• The psychological factor plays an important role in the effectiveness of treatment. There are a number of treatment methods that can achieve some success, but when they are discontinued, the disease returns. All currently used methods are most effective in mild forms of the disease and less effective in severe lesions. Various treatment methods can be divided into several groups:
• non-specific irritants: anthralin, croton oil, dithranol, etc.;
• agents causing contact dermatitis: dinitrochlorobenzene, diphenylcyclopropenone, dibutyl ester of square acid, etc.;
• non-specific immunosuppressants: corticosteroids, 8-methoxypsoralen in combination with UVA (PUVA therapy);
• specific immunosuppressants: cyclosporine;
• methods of direct action on hair follicles: minoxidil;
• alternative methods of treatment;
• experimental treatment: neoral, tacrolimus (FK506), cytokines.

Medicinal products for combating baldness

Until recently, scientists were amazed at the gullibility of people who were ready to try any means that promised hair restoration. However, as studies have shown, people are so easily suggestible that hair growth can be caused by an inert substance.

Various emotions and mental attitudes can have a strong effect on hair, causing it to grow or fall out. All this makes it difficult to objectively assess the effectiveness of various remedies for baldness. Additional difficulties arise from the fact that baldness can begin for various reasons. Accordingly, a substance may work for one type of baldness, but not for another.

The following substances, which are related to medicines, are used to treat alopecia:

• minoxidil and its analogues;
• dihydrotestosterone blockers and other antiandrogens;
• anti-inflammatory agents (corticosteroids);
• irritants with immunosuppressive action;
• substances that regulate proliferative processes in the epidermis;
• photosensitizers used in photochemotherapy. Physiotherapeutic methods and so-called alternative medicine - preparations based on natural compounds and plant extracts used by different peoples to strengthen and grow hair - are a good aid in the complex treatment of alopecia.

Photochemotherapy for focal alopecia

UV radiation plays a significant role in the treatment of alopecia. It is known that short-term stay of patients in sunny regions has a positive effect on hair growth.

However, it also happens that some patients experience an exacerbation of alopecia in the summer. PUVA therapy (photochemotherapy) is an abbreviated name for a method using photosensitizers (psoralens) and long-wave UV radiation of the A range. The division of the ultraviolet region of the spectrum into ranges A (320–400 nm), B (280–320 nm) and C (<280 nm) was introduced in medicine based on the different sensitivity of the skin to these types of radiation.

The skin is the least sensitive to UVA radiation.

Currently, local (for mild and moderate forms of focal alopecia) and general (for severe forms of the disease) PUVA therapy are used, using psoralens externally in the form of solutions (for mild forms), orally in the form of tablets or in combination (for severe forms). The course of treatment consists of 20-25 irradiation procedures for mild forms or 25-30 procedures for moderate and severe forms of the disease, carried out 4-5 times a week. Courses are repeated after 1-3 months depending on the clinical effect.

The following groups of psoralens are used:

• for oral administration - 8-methoxypsoralen, 5-methoxypsoralen;
• for local use - 1% oil emulsion of 8-methoxypsoralen ("Oxoralen-Ultra") and the synthetic drug 4,5,8-trimethylpsoralen (used in the form of baths).

The main advantage of topical application of psoralens is the elimination of nausea and headaches (a side effect observed in a significant proportion of patients taking psoralens orally).

Psoralens act on the skin only when exposed to ultraviolet light. During photosensitization, cellular DNA synthesis is selectively suppressed in the epidermis by photochemical binding of DNA to psoralen, which has a direct effect on the skin's immune system without inhibiting epidermal cell function. PUVA therapy is thought to affect T-cell function and antigen presentation, and to suppress local immunological attack on the hair follicle by depleting Langerhans cells. PUVA therapy provides general immunosuppression through direct or indirect (via interleukin 1) stimulation of prostaglandins E2, resulting in efferent lymphatic blockade.

PUVA therapy is performed only in a medical facility by a physician with special training and experience. The patient takes psoralen with low-fat food or milk 1.5 to 2 hours before irradiation. During the first session, an average dose of 0.5 to 3.0 J/cm2 (depending on skin type) or a minimum phototoxic dose is given. The amount of time spent in the treatment cabin varies for each patient. The irradiation time is recorded and increased with each session. Local use of 8-methoxypsoralen oil emulsion (1 mg/L) at 37 °C and UV irradiation with single doses of 0.3 to 8.0 J/cm2 for 20 minutes 3 to 4 times a week gives good results. After 24 weeks, with a total irradiation dose of 60.9 to 178.2 J/cm2, almost complete hair regrowth was observed in 8 of 9 patients.

Some patients may experience a relapse of the disease with a gradual reduction of PUVA, on average 10 weeks after stopping treatment. There is also a dependence of the effectiveness of PUVA therapy on the clinical form of alopecia, the duration of the disease, the stage of the process and the duration of the last relapse. PUVA therapy is combined with topical corticosteroids, anthralin, calcipotriol, aromatic retinoids (acitretin, etretinate). This combination makes it possible to use a lower total dose of UV radiation.

Contraindications for the use of PUVA therapy are: individual intolerance to drugs, acute gastrointestinal diseases, diabetes mellitus, thyrotoxicosis, hypertension, tuberculosis, pregnancy, cachexia, cataracts, tumors, diseases of the liver, kidneys, heart, nervous system, diseases characterized by increased sensitivity to light. It is inappropriate to carry out therapy on children and persons under 18 years of age, as well as on patients over 55 years of age.

A comparative analysis of scientific publications over the past 10 years suggests that PUVA therapy is less effective than topical immunosuppressive therapy in patients with focal alopecia.

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