Methods for diagnosing and treating skin pigmentation disorders

Elena Shchedrina , dermatologist, cosmetologist, teacher at DMK Ukraine (Ukraine)

Pigment formation is a complex biochemical process that depends on many factors. Skin color is determined by four pigments: melanin (brown) - accumulates in the basal layer of the epidermis, carotene (yellow) - located in the keratinocytes of the epidermis, oxyhemoglobin (red) - found in the capillaries of the skin, deoxyhemoglobin (blue) - located in the skin venules. A fifth pigment is isolated separately - melanoid, which is a product of the breakdown of melanin.

It is disturbances in the synthesis of melanin that lead to the formation of pigmentation

Treatment of pigmentation is impossible without understanding the mechanisms of melanin formation, as well as the causes of pathological pigmentation.

There are a huge number of pigmentation disorders - they are called melanoses. If the synthetic function of melanosomes and the distribution of melanin units in keratinocytes is disrupted, hyper- or hypomelanosis occurs.

Causes of dyschromia

There are endogenous and exogenous causes of pigmentation.

Endogenous include :

• genetic predisposition - people of the first phototype, who, according to the classification of the American dermatologist Fitzpatrick, have hereditarily white skin with many freckles all over the face and body. Exposure to ultraviolet radiation causes sunburn and an increase in the number of freckles;
• hormonal imbalances – the production of melanin is directly affected by the activity of the endocrine glands and hormones. A malfunction of the endocrine glands explains the appearance of pigment spots that occur during pregnancy, taking oral contraceptives and a number of medications, during menopause in women and other hormonal disorders;
• somatic - diseases of the liver, kidneys, gastrointestinal tract, dermatological diseases and metabolic disorders, vitamin C deficiency, as well as regular stress and nervous tension can cause the formation of age spots on the skin;
• age - with age, the skin becomes more and more susceptible to external irritants and the sun, which provokes the appearance of foci of hyperpigmentation, which are called “senile lentigo”.

Exogenous include :

• ultraviolet radiation – prolonged exposure to the sun or solarium can lead to the appearance of multiple age spots on the face and body; UV rays also provoke not only the activation of melanocytes, but the appearance of atypical cells, which is more dangerous than any age spots;
• violation of the integrity of the skin (mechanical, chemical, thermal injuries) - procedures that are accompanied by trauma to the skin, namely mechanical and ultrasonic facial cleansing for acne, injection procedures, injection of fillers, plastic surgery, the use of creams and ointments with a strong irritating effect, chemical peels , laser resurfacing, dermabrasion, all types of hair removal.

Considering all of the above factors, to eliminate pigmentation, you may need the help of not only a dermatocosmetologist, but also a gynecologist-endocrinologist and gastroenterologist. These specialists will help eliminate somatic problems of the body, and a dermatocosmetologist will deal with external treatment.

Types of dyschromia

There is the following classification of dyschromia:

• hypermelanoses : primary (congenital, hereditary, acquired) and secondary (post-infectious and post-inflammatory melasma);
• hypomelanosis : primary (congenital and acquired) and secondary (post-infectious and post-inflammatory hypochromia).

To diagnose dyschromia, dermatoscopy and histological examination are often used (if malignant neoplasms are suspected). It is also possible to use siascopy (spectrophotometric intracutaneous analysis - a diagnostic method for studying pigmented formations of the skin, based on the interaction of waves of light rays of different lengths with melanin, hemoglobin and collagen in the skin at a depth of up to 2 mm) and a Wood's lamp.

Management of patients with pigmentation disorders occurs in several directions (depending on pathomorphology, etiopathogenesis and the wishes of the patient)

Therapy for pigmentation disorders

Modern aesthetic medicine and dermatology make it possible to get rid of almost any type of hyperpigmentation.

Management tactics for patients with pigmentation include:

1. identification and elimination of somatic causes (consultation with an endocrinologist, gynecologist, gastroenterologist);
2. examination for the prevention of malignancy;
3. carrying out therapeutic measures in patients with hyperpigmentation in the autumn-winter period;
4. Prevention of hyperpigmentation through regular use of sunscreen with SPF of at least 30.
5. Before taking medications, you should first consult with your doctor to see if they increase skin sensitivity to the sun.

Today, doctors and patients have a wide variety of medical, cosmeceutical and surgical techniques to combat melasma.

External depigmenting agents are prescribed in the form of serums, creams, ointments, which are divided into three groups according to the mechanism of action, taking into account the pattern of melanogenesis:

• tyrosinase inhibitors - preparations based on kojic acid, arbutin, phytic and ascorbic acids, vitamin E, white mulberry extract, licorice salt (wild potassium glycyrrhizinate), licorice root, Hillarys Siliquosa algae extract. This algae is able to suppress pigmentation at several levels of the melanogenesis cascade: before melanin synthesis, it reduces the release of important mediators of melanogenesis, melanin synthesis; during melanin synthesis inhibits tyrosinase activity; after melanin synthesis, it inhibits melanocyte dendrites and controls the transition of melanosomes to keratinocytes;
• substances that reversibly inhibit melanin synthesis - preparations based on azelaic acid; preparations based on hydroquinone, used previously, are currently prohibited due to its toxicity (today, opinions on the use of hydroquinone are divided. In Europe, the ban on hydroquinone was discussed for some time, studies have not confirmed the danger of the substance, but European brands still use other whitening components Manufacturers from the USA and Canada include hydroquinone in their products).
• the enzyme lignin peroxidase eliminates already formed pigment and does not affect the process of melanogenesis, is well tolerated and has rare side effects.

It is also good to use the dermoelectroporation system - a non-invasive system for transdermal delivery of drugs containing active components that convert melanin into a colorless form into the deeper layers of the skin.

Mesotherapy procedures in this case will consist of injecting the pigmented area with solutions containing active substances such as vitamin C, glycolic, linoleic acids, multivitamin complexes, and heterologous type I collagen.

For a more pronounced effect on the pathological focus, more active methods are used:

• chemical peels based on AHA acids (glycolic, lactic, malic, citric, mandelic), BHA acids (salicylic), kojic, trichloroacetic acids, beta-carotene, cassia, enzymes (papain, bromelain), retinoids. Alkaline peelings based on thioglycolic acid, magnesium oxide and calcium carbonate are also used, when applied in less than three minutes, the pH of the skin rises to 12.7 units, thereby causing a powerful keratolytic effect, increasing skin permeability and the rate of regeneration, on which it is based therapeutic effect of the drug. Different depths of impact and penetration allow for a variety of courses of procedures with different rehabilitation periods;
• controlled microdermabrasion is a procedure for removing pigmented lesions by mechanical exfoliation with a stream of highly purified aluminum oxide microcrystals. Thanks to this manipulation, the surface layer of the epidermis is delicately removed and at the same time the renewal of the deep layers, as well as the dermis, is stimulated;
• laser therapy is a method based on the phenomenon of photothermolysis, that is, the ability of pigment spots to absorb the energy of a laser beam, which subsequently leads to their destruction and provides a good whitening result;
• phototherapy – removal of age spots using pulsed light radiation, which leads to stimulation of the production of collagen and elastin;
• ELOS therapy is a combination of light energy and electric current. By combining IPL and RF radiation, it is possible to achieve the removal of epidermal hyperpigmentation with minimal risk of damage to surrounding tissues;
• cryotherapy – pigmented areas are exposed to liquid nitrogen, resulting in their death. But with this method there is a possibility that scars will remain.

In the treatment and correction of hypopigmentation, it is also possible to use external preparations, homeopathic and medicinal products containing ammifurin, algae extracts . However, for systemic skin diseases such as albinism, these products are not effective. For such diseases, photochemotherapy is used. This technique is most often used to treat psoriasis and atopic dermatitis, but in some cases it is also used to treat depigmentation. The procedure increases the skin's sensitivity to ultraviolet radiation, but has a pronounced cytostatic side effect, which can lead in some cases to skin cancer. Recently, surgical melanocyte transplantation has become increasingly common.

Thus, pigmented lesions can be dealt with based on an integrated approach to this problem, taking into account an understanding of the individual mechanisms of its occurrence.

First published in ​"Les Nouvelles Esthétiques Ukraine" No. 5 (111) 2018