Additional methods of assessing the condition of the skin

In modern cosmetology, various additional non-invasive methods for assessing the skin condition are widely used, both for the purpose of diagnosing certain diseases and conditions, and for evaluating the effectiveness of various cosmetics or procedures. Such techniques are becoming increasingly popular in research and day-to-day practice, due to the fact that in the past they pay much attention to the standardization of the evaluation of the effects of cosmetic preparations and procedures.

To assess the dynamics of changes on the background of various medical and cosmetic procedures, the method of photo-documentation is popular. When shooting the skin, it is important to use the correct standard skin lighting, it is also recommended to do both side and side shots.

In order to identify the characteristic luminescence in fungal and infectious diseases or skin discoloration in pigmentary disorders and a number of inflammatory dermatoses, examination in a fluorescent lamp with a Wood filter is widely used. With the help of modern instruments (VisioFace®, CK electronic), photography of the skin area in the "white range" and under ultraviolet illumination is also used, which is important for the diagnosis of a number of pigmented lesions and photodamage of the skin.

In recent years, a method has been used to study the optical properties of the skin in normal and pathological conditions, which consists in assessing the state and changes in the fluorescence intensity of the skin, in particular sebum due to porphyrins.

In dermatocosmetology, topical is the evaluation of the relief (texture) of the skin. Under the skin relief is meant the depth and width of the grooves, as well as the size of other irregularities present on the surface of the skin. The skin relief is one of the most important parameters of its functional state. The relief is assessed using a skin-visionimeter that determines the depth and height of various points, depending on how they absorb and reflect light. In addition, a technique is used to remove the silicone impression from the surface of the skin and then study it with a fine diamond needle.

To study the skin microrelief, a method such as a superficial biopsy of the stratum corneum is used. Advantages of the method are simplicity, non-invasiveness, painlessness. The method allows to estimate the rates of desquamation, to study the ratio of active and non-active follicles. The film applied to the surface of the skin with special discs and cyanoacrylate glue is dried together with the corneocytes after the glue dries. The material fixed to the glue is stained using histological, microbiological and histochemical techniques. If necessary, to investigate the intensity of coloration of corneocytes, chromometry, their size and shape-morphometry, are used. Currently, both classical methods and immunomorfologic, immunohistochemical and electron microscopic studies of corneocytes are used. The latter method also provides information on the nature of the microflora on the surface of the skin.

Skin pattern and distinctive features of a number of rashes are examined using dermatoscopy. An enlarged (up to 90) image of the skin area is transferred for analysis to the monitor, with the exact sizes, boundaries, color, surface texture of the elements, some intra-epidermal (intradermal) structures being evaluated. Dermatoscopy is used for early diagnosis of benign and malignant neoplasms of the skin, including melanoma-dangerous nevi, melanoma and melanoma.

To determine the acidity of the skin, litmus paper was used before. This technique is currently practically not used because of the high risk of developing dermatitis and the doubtfulness of the results obtained. Use the electrochemical method using a pH meter, or pH meter. The principle of operation is based on measuring the potential difference between the buffer solution and the hydrolipid mantle of the examined skin area. Computer processing and recalculation of the voltage values in pH values to within one-tenth of the accuracy allow to obtain data on the acid-base state of the hydrolipid mantle of the skin.

When assessing the degree of moisture in the skin, the humidity of the stratum corneum is measured using a corneometer instrument. The principle of the device is based on the study of electrical conductivity. The higher the electrical conductivity of the skin, the higher its moisture content. The measuring probe has two electrodes - positive and negative charge. Between them is a dielectric. When the skin contacts the skin between the electrodes, an electric current arises, the electrical conductivity and, correspondingly, the skin's moisture, are determined by its strength. The advantage of the method is its simplicity. The disadvantages include the risk of dermatitis in the place of contact with electrolytes

With the aid of the evaporimeter device, important information on the hygroscopicity and barrier properties of the skin can be obtained by measuring the amount of water absorbed by the skin and the rate at which it gives it away (TENL). The intensity of this process is investigated using a probe equipped with special sensors. A serious drawback of the method is the dependence of the measurement results on the slightest fluctuations in air and its temperature.

To study the elasticity of the skin, cutometry is used. A special optical measuring system processes the information about the area of the skin located in the probe hole, the results are recorded on the monitor as a curve of elasticity (in hundredths of a millimeter). The cytometer also determines the degree of damage to collagen and elastic fibers. The disadvantage of the device is that it can assess the elasticity only in a particular section of the surface layer of the skin.

Often in cosmetology, there is a need to evaluate the activity of the sebaceous glands. Determination of the exact amount of sebum on the skin surface is called sebometry. On the head of the measuring cassette is a special opalescent film made of plastic, which is applied to the skin for 30 seconds. Then the cassette is laid in a sebometer-photometer and examines the fat fingerprint. The principle of spectrophotometry is used: the result depends on the intensity of absorption by the fatty imprint of light radiation.

The method of lipometry is close in nature to sebometry. It allows you to determine the amount of sebum on the surface of the untreated skin (basal level). The presence of a dynamometer allows the standardized pressure of glass to be applied to the surface of the skin. The use of standard calibration (mg lipid / sm ² ) in the study facilitates the comparative analysis of the results of the study. The greasiness of normal skin is 100-200 mg lipid / sm ², fatty - more than 500 mg lipid / sm ², dry - 50 mg lipid / sm ².

The "Sebutape" technique assumes the use of special films from a hydrophobic microporous polymer with an adhesive surface. On a clean skin, apply a film with an exposure of 20-30 minutes. The area of the fat spot formed as a result of the penetration of the released lipids through the adhesive layer into the micropores is directly proportional to the secretory activity of the sebaceous glands. Normally, the resumption of salivation is, according to this technique, 0.6-2 mg / (sm ² • min).

At present, ultrasonic skin diagnostics are widely used, which makes it possible to assess the degree of moisture, the state of collagen (Schmid and elastic fibers of the dermis.

Thermometry is used to assess the skin microcirculation. This technique is based on the effect of reducing the temperature of tissues when their perfusion is disturbed. The advantages of the method are the ability to conduct numerous repeated studies. Disadvantage of the method is that the temperature change is quite inert, even in the absence of blood flow. Liquid crystal thermography is a good method for diagnosing circulatory disorders in cellulite. It allows you to visualize and measure the temperature and heat flux fields corresponding to the intensity of microcirculation of a particular body part. In this hypo- and hyperthermal regions are fixed by encapsulated liquid crystals located in flexible thermographic plates, in the form of foci of a certain color, size and shape.

Microcirculation of the skin can also be assessed with the help of ultrasound dopplerography. They study the dynamics of blood flow in the microcirculatory bed, determining its linear and volumetric velocity. The method is based on recording the progress of erythrocytes in the vessels of the skin. The received signal is transformed into sound or graphic. The principle of laser Doppler flowmetry is based on recording the spectral scattering of a monochromatic light beam by moving blood cells. Ultrasonic dopplerography and laser flowmetry can be used for long-term dynamic observation. The techniques are widely used in plastic surgery to assess the state of microcirculation before plastic flap, as well as to assess the microcirculation of the distal limbs with onychodystrophy. In a number of cases, clinicians supplement dopplerographic studies with pharmacological tests with acetylcholine (endothelium-dependent vasodilation) and nitroglycerin (endothelium independent vasodilation) to determine vascular reactivity, which greatly expands the possibilities of the described techniques.

Widely used capillaroscopy of the nail bed allows to evaluate a number of important static and dynamic parameters of microcirculation. The technique was used to characterize blood circulation with age-related skin changes.

Radioisotope research provides objective information about blood filling of tissues. Used in plastic surgery to determine the viability of autografts. The possibilities of this method are essentially limited by measures of radioactive safety.

Impedance rheoplethysmography records the change in electrical resistance of soft tissues when their blood filling fluctuates. The method is based on the measurement of the impedance of an alternating current at various frequencies with the subsequent determination of the coefficient of polarization

Used to monitor the skin after peeling. Micro plethysmography determines the blood filling of capillaries. To assess the functional state of capillaries in recent years began to use mexametry, or capillarometry, the determination of the diameter of the cross section of capillaries in dynamics, the study of the state of microcirculation in terms of the degree of expression of blood filling of capillaries.

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