Methods for diagnosing psoriasis: laboratory and instrumental

It so happened that the entire human body is covered with a unique multifunctional material - the skin, in parallel with other organs that perform the function of breathing, thermoregulation, nutrition and body protection. Diseases of this peculiar organ can lead to various violations of the work of other organs and systems. But statistics is inexorable, and skin diseases account for 15% of the total mass of diseases with which people turn to the family doctor. At the same time, about 2-4% of them (according to various sources) are psoriasis. And, despite the fact that the diagnosis of psoriasis for an experienced doctor is not particularly difficult, there are certain nuances that must be taken into consideration when assigning and conducting diagnostic studies.

A little about the disease itself

Psoriasis is one of the least studied pathologies in humans. Moreover, disputes still go around the etiology of the disease, and around the causes that cause it, not to mention effective methods of treating the disease. So psoriasis to this day is considered an incurable disease of controversial nature.

According to the latest studies of psoriasis, there are two main hypotheses for the development of psoriasis. One of them claims that psoriasis is the primary skin disease, which is characterized by a violation of the normal process of maturation and division of skin cells and excessive growth and multiplication (proliferation) of these cells due to a dysfunction of the epidermis. The immune response is considered secondary.

Another hypothesis insists on the secondary nature of pathology, i.e. Cell proliferation there is an inflammatory reaction caused by a malfunction in the functioning of the immune system, which "native" cells begin to perceive as alien bodies.

Studies conducted on animals do not allow scientists to dwell on one of the versions, since they do not allow to reproduce the complete picture of the pathology in humans. Nevertheless, they make it possible to identify certain risk factors, which can provoke the emergence of specific psoriatic symptoms, on the basis of which the diagnosis of psoriasis is carried out.

Such factors include:

• The patient suffered severe stressful situations,
• traumatic skin lesions,
• acute and chronic infectious diseases,
• changes in climatic conditions of residence,
• HIV infection,
• taking medications under the condition of intolerance of their components, which causes allergic skin reactions,
• use of some types of cosmetics for hair and skin, household chemicals, etc.

Some role in the development of pathology (in the presence of certain triggers, mentioned above) can play hormonal disorders, hereditary predisposition or skin features (thin, dry sensitive skin is susceptible to disease more than other types).

But sometimes the appearance and exacerbation of psoriasis occurs and for no apparent reason, which puts scientists at a dead end. Nevertheless, the disease exists, it is widely spread, which means there is a need for further study and search for effective methods for diagnosing psoriasis, which allows not only to name the problem by "name", but also to determine the cause that caused the development of the pathological process to lead active struggle against the disease in both directions.

[1], [2], [3]

Basic methods for the diagnosis of psoriasis

To say that the diagnosis of psoriasis today is difficult, it will be untrue. The symptomatology of the disease is so obvious that an experienced doctor can recognize the disease without any difficulty.

The main specific symptom of psoriasis is a skin rash. At the beginning of the disease, it looks like a small pink seal on the skin with a diameter of about 1-2 mm. A little later they acquire the form of tubercles with a bright pink border (growth zone), which are covered with whitish loose loose scales. Bumps gradually increase in diameter (grow). Usually their size ranges from 2-3 to 7-8 cm.

The appearance of specific growths (plaques) is due to disturbances in the process of cell formation, when the still-dead old cells are layered onto prematurely emerging new cells.

Plaques can expand and unite in groups, forming large zones of damage, or for a long time to remain at the same level in the form of single specimens.

Most often, apart from examining complaints and examining the patient's skin with scraping of other methods of investigation, it is not required.

Laboratory tests of urine, blood and feces in this case serve for the purpose of effective treatment of pathology, taking into account the individual characteristics of the patient's body. But in severe cases of pathology or in the presence of controversial symptoms, various analyzes will help not only to determine the degree of development of pathology and differentiate psoriasis from other similar diseases, but also to identify concomitant diseases in the patient.

With a fuzzy clinical picture of the disease, one of the most effective methods for the diagnosis of psoriasis is skin biopsy, when a microscopic study takes a small piece (about 6 mm) of skin. This study aims to exclude other skin pathologies with similar symptoms, as well as histological confirmation of the diagnosis of "psoriasis". A biopsy is usually performed only once, but if the manifestations of the disease periodically change, you may need a second skin analysis by a pathologist.

[4], [5]

Clinical diagnosis of psoriasis

Psoriasis, although not very wide symptomatology, but its manifestations can be seen not always. This wily pathology is characterized by a wavy course, in which various provoking factors (stresses, seasonal changes, etc.) can provoke an exacerbation of the disease, and effective treatment can cause persistent remission for a long period.

The disease is diagnosed mainly by its external manifestations in the form of specific skin rashes. But these manifestations can be different at different stages of development of the pathological process.

So for the progressing stage, there is the appearance of single or multiple papules with a bright pink border, which are prone to growth and fusion. Over time, they are transformed into slightly psoriasis plaques that rise slightly above the healthy skin, which begin to peel and painfully itch.

At the regression stage, the pathologies of the papules (plaques) become flatter, turn pale, the scaling and itching noticeably decrease. Sometimes plaques disappear at all, but most often become barely noticeable due to changes in skin pigmentation at the site of the lesion (dark or light spots).

The stationary stage, or the period of remission is characterized by the absence of new rashes and any changes in the appearance of the old.

In addition, psoriasis can have different localization and some differences in symptoms, in connection with which the following types and types of disease are distinguished:

• Normal, or vulgar psoriasis, which is considered the most common form of the disease. It appears in the form of silvery-white scaly patches. It is most often localized in the region of the knee or elbow joints, but it can also appear in other parts of the body (on the hands, on the soles of the feet, on the head along the hair growth line, etc.).
• Exudative psoriasis has the same localization, but the surface of the spots is covered with a yellowish crust, from under which blood or a light yellow liquid (exudate) can be released. This happens, as a rule, against the background of developing diabetes mellitus, obesity and other pathologies of the endocrine system.
• Guttate psoriasis often appears on the body (especially in the thigh and buttocks) and legs, while the rashes are in the form of red or lilac drops. It develops against the background of streptococcal infection.
• Point psoriasis is diagnosed if the above-described rashes have the size and shape of a pinhead.
• The coin-like psoriasis is larger rounded rashes, which in diameter reach 3-5 mm.
• Pustular psoriasis is characterized by the formation of pustules in the form of islets of inflammation with purulent contents. Such islands can be located as on the feet or palms, so on the whole body. May be accompanied by an increase in body temperature, weakness, stool disorder, chills, etc.
• Inverse, or psoriasis folds is characterized by the fact that psoriatic rashes are localized mainly in large folds of the body.
• Seborrheic psoriasis is characterized by the location of rashes in the scalp. At the same time, yellowish crusts are observed on the site of the rashes. The disease most often develops against the background of already existing seborrhea.
• Palmar-plantar psoriasis. Its name speaks for itself, outlining the localization of psoriatic eruptions.
• Psoriasis of the nails is a special form of the disease, in which the nail plate and skin beneath it are affected. In this case, as with fungal infection, thickening and destruction of the nail is observed.
• Psoriatic erythroderma is accompanied by the appearance of a large number of reddish plaques covered with silvery or yellowish scales. Plaques tend to combine with the formation of large itchy lesions, which is often accompanied by an increase in temperature and an increase in lymph nodes.
• Psoriatic arthritis (atropatic psoriasis) with localization in the area of the joints (phalanx of fingers, wrists, spine area, etc.). At first it is manifested only by skin rashes over the joints, but if there is a predisposition and there is no effective treatment, the disease can spread to the joints themselves, limiting their mobility.
• Atypical form of psoriasis is diagnosed if the localization of plaques is not characteristic of this type of psoriasis or if additional symptoms unusual for the disease are present.

Clinical diagnosis of psoriasis is to study the patient's complaints, as well as an analysis of the available symptoms, which can indicate a particular type, as well as the type of psoriasis. But on the basis of only an external examination to put the correct diagnosis is difficult, although almost all the symptoms, as they say, are obvious.

[6], [7], [8], [9],

Analyzes for psoriasis

As already mentioned, blood tests, urine and feces with psoriasis do not play a decisive role in the formulation of the final diagnosis. And yet some useful information from the conclusion of the laboratory doctor can draw.

The most informative in terms of diagnosis of psoriasis is a blood test, especially if the doctor is experiencing certain difficulties in diagnosing. In psoriasis, usually 3 types of blood tests are prescribed:

• general, or clinical analysis,
• biochemical analysis,
• a blood test for autoantibodies.

The analysis of blood is especially effective in progressing psoriasis or its severe stage, because with mild forms of pathology there is practically no change in the composition of the blood. The study of the composition of blood and the resulting biochemical processes will help not only to identify certain types of psoriasis, but also the accompanying diseases:

• A general blood test helps determine the role of inflammatory, rheumatic and autoimmune factors in the development of pathology, the presence of endocrine and biochemical disorders in the body. It is on the basis of this analysis that it is possible to diagnose psoriasis developing against the background of such pathologies as leukocytosis, anemia, diabetes mellitus, etc.
• The study of rheumatoid factor (the presence of protein in the blood) allows you to differentiate psoriatic disease from rheumatoid arthritis. In the first case, the result will be negative.
• Indicators of ESR are important for the diagnosis of this type of pathology as psoriatic erythroderma and pustular form of psoriasis. With the above pathologies, there are changes in the rate of erythrocyte sedimentation.
• A slightly elevated level of urea can indicate the development of a severe form of psoriasis, which causes abnormalities in the functioning of internal organs. If the content of uric acid is much higher than normal, this indicates the development of gout, and not the manifestations of psoriatic arthritis.
• Biochemical blood test helps to determine how the liver and kidneys work, to determine the activity of inflammatory and rheumatoid factors, to see violations of water-salt metabolism, to reveal the imbalance of microelements.
• The analysis of blood on autoantibodies allows to reveal in time the unsatisfactory state of the immune system (in particular, the presence of HIV infection and other risk factors), and the violation of the hormonal background. The analysis is conducted to assess the general condition of the patient, as well as to exclude allergic and oncological diseases, identify various infections in the body.

Clinical analysis of urine in psoriasis usually remains unchanged. But with a prolonged progressive course of the disease, it can show a change in the water-salt balance due to dehydration of the body.

The analysis of feces is carried out purely for the purpose of revealing helminths, which reduce the treatment of any pathology to "no."

[10], [11], [12], [13], [14], [15], [16], [17]

Instrumental diagnosis of psoriasis

If the above analyzes do not clarify the problem, for example, in case of severe disease or unspecific symptoms, additional methods of psoriasis diagnosis may be required, such as skin biopsy, microflora seeding, potassium oxide testing, prolactin analysis, syphilis testing.

Most often, the case is limited to a skin biopsy, as a result of which: a large number of neutrophilic leukocytes called Rete bodies, an increase in the thickness of the keratinocyte layer with histological immaturity, an increase in the level of T-lymphocytes (protectors) and macrophages, as well as other phenomena peculiar to psoriasis.

A skin biopsy is performed in conjunction with histological studies. In this case, the same psoriatic lesion is subjected to the study. The following indicators indicate the positive result:

• absence of a granular layer of the epidermis, protecting the skin from dehydration,
• thickening of the germ layer of the epidermis due to elongation and edema of the epidermal processes, while above the dermal papillae this layer is much thinner than normal,
• a large number of blood vessels (capillaries) at the site of injury,
• accumulation of neutrophilic leukocytes (granulocytes) in the stratum corneum (Munro micro-abscesses),
• predominantly lymphohistiocytic infiltration around the vessels.

The main method of diagnosing psoriasis is taking a scraping from the affected area with a slide and analyzing the observed signs (phenomena) of psoriasis, called the psoriatic triad.

Signs of the psoriatic triad appear in a certain order. The first to know about yourself is the phenomenon of stearin stain. Such a name he received in connection with the similarity of his manifestations with grated stearin. If you remove the top layer of the papule, under it there is noticeable peeling (scales similar in appearance to stearin).

The phenomenon of the terminal film is the last indicator of the existing pathology. It can be seen at the place of the removed scales, under which it is found smooth as a polished surface of pink color.

If the scraping is carried out further, microscopic hemorrhages appear in the form of small droplets of blood on the surface of the affected area under the film. This phenomenon is called the phenomenon of pinpoint bleeding (or a symptom of bloody dew).

Psoriasis is also characterized by another specific symptom, known as the Kebner phenomenon, which is observed during the acute phase of the disease. It consists in the formation of new foci of eruptions in places exposed to irritation, or where there has been damage to the skin. Its appearance in some cases helps to clarify the diagnosis.

Some information about the problem can provide consideration of the affected area of the skin in UV rays with a wavelength of 308 nm, generated by an excimer laser. With psoriasis, scaly rashes begin to glow.

If psoriatic rashes are localized in the joint region and are accompanied by pain in them, there are all prerequisites for diagnosing psoriatic arthritis. To specify the diagnosis, in addition to the analysis of blood, will help X-rays of affected joints.

One of the new non-traditional methods of instrumental diagnosis of psoriasis is hemoscanning, which is a visual study of fresh blood by means of a special electron microscope with a large degree of magnification. But to use it as the main method of investigation is inexpedient, since the probability of incorrect diagnosis is great.

Biomicroscopy in the diagnosis of psoriasis

In the diagnosis of psoriasis, eczema and other dermatitis, one of the most effective methods of investigation is contact biomicroscopy, known since the times of the Soviet Union.

The use for diagnostic purposes of contact microscopes brought close to the object under study allows observing the physiological, pathological and transport processes occurring in living human organs, making measurements and fixing various indices, and even making a photomicrograph of the skin.

The basis of contact instrumental examination of the skin was colposcopy, which was widely used in gynecological examinations. The use of a stereomicroscope for the study of external skin gave an impetus to the emergence of various methods of contact biomicroscopy, used in dermatology to diagnose skin diseases, including psoriasis.

The most valuable in this respect is contact luminescence biomicroscopy, which is one of the variants of laser fluorescence spectrometry. In this case, the study of the "behavior" of tissues under a microscope is combined with their luminescence analysis, which makes it possible to detect pathology at an early stage of development.

Diagnosis can be carried out both with the use of additional coloring of the skin with fluorochromes, and without it. To study the structure of the horny layer, tinting is usually not required, it is sufficient for the skin to have its own fluorescence. But in order to learn more about individual scales of psoriatic plaques, to reveal or exclude the phenomena of Munro's pseudoabsesses and parakeratosis peculiar to psoriasis, the skin should be colored with acridine orange (optimal concentration 1: 5000).

The very technique of contact luminescent biomicroscopy is based on the fact that the enhancement of cellular respiration causes a change in the natural fluorescence of the skin toward the yellow-green spectrum. At the same time, the blue glow is noticeably damped. In the diagnosis of psoriasis, this manifests itself in the detection of the cells of the stratum corneum, which differ in the nucleus of bright emerald color and pale green cytoplasm, which indicates the phenomenon of parakeratosis. By the expression of parakeratosis, which indicates the degree of disruption of cell maturation, it is possible to judge the activity of the psoriatic process itself.

Some leukocytes in the stratum corneum may have an unusual color. They are characterized by a green glow of the nucleus and a red color of the cytoplasm. Usually such cells assemble into groups, forming pseudoabsesses of Munro, which again allows one to judge the development of psoriasis.

Contact biomicroscopy finds its application only in the diagnosis of the pathology itself, but also to monitor the dynamics of the process during therapeutic measures and the correction of therapeutic prescriptions (for example, to determine the time of cancellation of drugs used in psoriasis).

[18]

Acupuncture points in the diagnosis of psoriasis

According to the theory of acupuncture, the cause of any illness lies in the violation of the energy balance between the main meridians, which in the human body there are 12 pieces: meridians of the lungs, large intestine, small intestine, stomach, liver, gall bladder, spleen, heart, pericardium, bladder, kidney and meridian of three body cavities. Plus some information can be obtained from an additional 8 meridians. Inside these meridians there are certain acupuncture points, which are used for the diagnosis and treatment of various diseases, including psoriasis.

If a person falls ill, an imbalance of energy is observed in different meridians. So psoriasis is considered a disease with reduced energy in the area of the lung meridian.

Reducing the energy potential of one of the meridians entails its increase in others. To find a meridian with a large defect or excess energy, according to various methods of alternative medicine, can be in various ways, which number more than a hundred. Such methods include acupuncture diagnostics by language, ears, eye iris, chakras, spine, pulse, etc.

With the development of radio electronics in the 1950s, it became much easier to discover the "sick" meridian, because energy can now be measured with the help of special instruments. Demonstrative in this regard were electropuncture diagnostics according to Voll and the method of Riodoraku.

Both methods of diagnosis consider the human body as an element of an electrical network with its own energy potential (biopotential having a current strength of the order of 3-6 microamperes), which can vary in different meridians in accordance with the pathology that exists.

According to the method of Riodoraku, a complete picture of the patient's health can be made only by measuring the strength of the current at the exit points on the skin of various meridians. These data are entered in a special card Riodoraku, according to which the doctor can diagnose before the first signs of the disease appear.

The Voll method is also one of the safest and most effective methods of preventive diagnostics, which does not require special efforts and cumbersome equipment. The device for measuring skin biopotential is based on the fact that the resistance force of the internal electromotive force of various acupuncture points when exposed to them with an electrical voltage of 1.3-1.5 volts with a current strength of 15 to 20 μA causes the instrument needle to stop in a certain position. It is this indicator that determines the state of the energy potential in a specific biologically active point.

To measure the potential, it is sufficient for the patient to hold one electrode in his hand, while another doctor applies to the acupuncture point. Normally, the biopotential is 50-60 units on the scale of the Voll apparatus.

Currently, there are numerous development of apparatus for the diagnosis of psoriasis and some other pathologies that will not only detect the disease, but also determine the stage of its development by measuring individual parameters of the amplitude and phase of the biopotential in the region of acupuncture points of the corresponding meridian.

[19], [20], [21], [22], [23], [24]

Differential diagnostics

Despite the fact that the diagnosis of psoriasis often does not cause difficulties and it is fairly easy to diagnose by specific external signs, there is a certain probability of error, especially if the symptomatology is expressed implicitly or there are symptoms indicative of lesions of internal organs. Here, the differential diagnostics comes to the fore, based on the information obtained during the examination of the patient, the study of the anamnesis, laboratory and instrumental studies.

The purpose of differential diagnosis of psoriasis is to isolate this pathology among others with similar symptoms or to refute the previously delivered preliminary diagnosis.

It is important to understand that psoriasis is a multifaceted disease. Its various forms and forms can manifest themselves in different ways. This state of affairs only expands the spectrum of pathologies with which differentiation is necessary.

For example, seborrhoeic psoriasis in the beginning in many ways resembles seborrhea, caused by disturbances in the work of the sebaceous glands. Thus there is an ecdysis and an itch, as at a psoriasis.

From seborrhea, psoriasis is different in that the psoriatic rash is localized not over the entire head, but along the edge of hair growth, beyond its limits. At the same time, hair loss is not observed, and the skin on the affected areas remains dry.

With seborrheic dermatitis with localization on the scalp, the rashes do not spread beyond the limits of hair growth. On the body, such foci are located in places rich in sebaceous glands. Eruptions have clear boundaries without pink edging, characteristic of psoriasis. They are thinner, with yellow pale scales, painful, but not bleeding when scraping.

Eruptions in seborrheic psoriasis can spread further to the face and neck skin, resembling psoriasis neurodermatitis. But again, with psoriasis, there is no loss of hair and a pronounced change in the hue of the eyelids, and a small scaly rash does not have psoriasis-specific phenomena when scraping.

Pustular form of psoriasis with a superficial examination can easily be confused with the same syphilis. The difference between these pathologies is that with pustular syphilis, peeling of the papules is noticeable only at the edges, and not along the entire perimeter. Plus, there is a noticeable increase in lymph nodes.

It is not difficult to distinguish psoriasis from allergic or microbial eczema. Despite the fact that in both pathologies there is severe itching in the lesions, the characteristics of the rashes are still different. Psoriasis manifests itself in the form of scaly plaque, while the rash with eczema looks like a bubble. Even if the burst and dried up vesicles resemble psoriatic scales, when they are removed, a damp surface without spot hemorrhages is formed.

Great similarity to psoriasis is another insufficiently studied disease, called parapsoriasis. Diseases differ in nature, although they have similar manifestations, especially in the case of drop-shaped forms of pathologies.

Eruptions with parapsoriasis have some similarity with psoriasis rash. There are the same silvery scales on the surface of the papules, but when they are scraped, there are no phenomena of the psoriatic triad. And the papules themselves have a different size.

In contrast to psoriasis, parapsoriasis very rarely chooses the location of its localization of the scalp, as well as the area of the elbow and knee joints.

Psoriasis is one of the varieties of lichen, which causes its second name, "scaly lichen." The need to distinguish psoriasis from other lichen species arises due to the fact that many varieties of lichen are infectious and pose a danger to others.

The greatest similarity with psoriasis is red and pink lichen, but if the former is not dangerous to others, then the latter can be transmitted by direct contact with a sick person.

When diagnosing psoriasis, doctors may encounter great similarity in the external manifestations of red and scaly lichen. In both cases, scaly pruritic eruptions occur with a shiny smooth skin when they are scraped. But if in psoriasis skin and growth zone have a pink or reddish color, then for red lichen, the staining of the affected area is characteristic of a rich crimson red and even purple hue. More information for differential diagnosis of psoriasis gives a blood test. With red lichen, the number and activity of T-lymphocytes are reduced.

Pink deprive unlike psoriasis has a rapid and active development with the appearance of new rashes, covering an increasing area. The onset of the disease is most often accompanied by an increase in temperature and an increase in lymph nodes.

Manifestations of psoriasis on the nails are in many respects similar to fungal infection (rumbomycosis, candidiasis, etc.). There is a change in the appearance and thickness of the nail plate, the destruction of the nail. Precisely put the diagnosis of microbiological research. Nevertheless, there are a number of signs by which you can determine what the doctor is dealing with: psoriasis or nail fungus.

For psoriasis, the appearance around the affected nail is a pink or reddish rim, which is not observed with the fungus of the nails. But with a fungal lesion of the nail under the nail plate, purulent discharge with an unpleasant odor, which is not characteristic of psoriasis, is collected.

In addition, the fungal infection is prone to spread to other fingers and toes, and psoriasis usually affects single fingernails.

That's only in most cases there is an attachment of a fungal infection to psoriasis, especially with reduced immunity, which will show a microbiological study. So, the exact diagnosis delivered during the differential diagnosis will help to find effective methods of treating nail lesions, by combating the nail fungus and achieving persistent remission in psoriasis.

X-ray studies and a general blood test are useful in differential diagnosis of atropatic psoriasis. To distinguish psoriatic arthritis from rheumatic for an experienced doctor is not difficult. At the first indicate a characteristic rash and extensive joint damage. In favor of the second speak lesions of proximal interphalangeal joints, while psoriatic arthritis affects the terminal (or distal) joints.

But not always the symptoms manifest themselves clearly, which complicates the diagnosis of psoriasis. The rheumatic factor in psoriasis can be monitored by blood analysis, and X-rays can help assess the extent and location of lesions.

As we see, it is very difficult to overestimate the role of differential diagnostics in this case. After all, the correct diagnosis determines the effectiveness of treatment and the further life of a patient suffering from an incurable or treatable disease.

[25], [26], [27], [28], [29], [30]

Diagnosis of psoriasis in children

As is known, psoriasis equally affects both women and men, not having certain age limitations. It affects both adults and children, including babies. Symptoms of psoriasis in children are similar to manifestations of the disease in adult patients. But as for varieties and forms, we can say confidently: the pustular form of psoriasis, as well as psoriatic arthritis and erythroderma in children is observed only in isolated cases.

The most common forms of pathology in children of different ages are plaque and teardrop-shaped psoriasis. According to the research, 8% of infants have specific flaky eruptions in the form of plaques. The cause in most cases becomes heredity (if the mother or father is sick, the probability of the disease is 25%, if both parents - up to 70%) in combination with environmental and emotional factors.

In infants, squamous lichen, which is also called diaper psoriasis, is easily confused with the usual skin irritation when it comes in contact with an unfavorable environment or the same dermatitis. Psoriatic rashes have the same localization in the buttocks and hips of the baby. Most often in infants, you can see a drop-shaped form of psoriasis, which subsequently spreads to other parts of the body.

In childhood and adolescence, cases of plaque form of psoriasis are frequent, which begins with the appearance of scaly crusts with a pink border on the knees and elbows of a small patient. Psoriasis can also affect the scalp of the child, as well as nails and feet.

Diagnosis of psoriasis in children is often carried out immediately during the examination of the child. Doctors say that it is not difficult to do this, because severe forms of pathology with controversial symptoms are uncommon for children. Usually the picture is clarified by an external examination with the study of complaints from the words of parents and a small patient.

For the correct diagnosis, everything is important: hereditary predisposition, which is revealed when the parents are questioned, the time of the appearance of the rash and its behavior, the seasonality of the rashes, the presence of itching in the area of the lesion, etc.

Sometimes doctors resort to the help of a dermatoscope, allowing for a strong magnification to examine on the screen individual fragments of scaly rash.

It is very important to differentiate psoriasis in a baby from other pathologies with similar symptoms. Such pathologies, characteristic of childhood, include:

• ichthyosis of the skin with changes in the horny layer,
• xerosis in the form of dry scaly and itchy skin,
• keratosis of the skin with disturbances of its keratinization,
• varieties of lichen (red, pink, ringworm),
• different types of dermatitis
• fungal infection on the nails,
• allergic or microbial eczema,
• lupus erythematosus in the form of autoimmune inflammation of the skin,
• fungal skin lesions,
• Enteropathic acrodermatitis against a background of zinc deficiency in young children,
• impetigo in connection with the introduction of staphylococcal infection, which, after the formation of the stems, is similar to psoriasis,
• and even the usual skin irritation in infants.

To this end, scraping is performed, and in some cases, a biopsy of a piece of skin affected by the disease. The study of the taken part of the skin under the microscope and histological studies allows excluding tumor processes inside the skin and other pathologies dangerous for the baby. When scraping an obligatory condition for the diagnosis of "psoriasis" is the presence of the psoriatic triad, which was written above.

The need for diagnosis of psoriasis in children and timely treatment of it is caused by the fact that the disease tends to move from mild forms to heavier ones (for example, psoriatic arthritis) with lesions of internal organs. In addition, psoriasis increases the risk of developing metabolic diseases of an autoimmune nature, which can lead to a persistent increase in blood pressure, the development of diabetes mellitus, etc. Not to mention the emotional discomfort associated with the disease, leading to low self-esteem, isolation from society and frequent depressions.

[31], [32]