Psoriasis is a pathology in which the human immune system mistakenly attacks healthy skin cells. As a result, scaly plaques appear on its surface, which can be very itchy and even painful. Sometimes the disease is also accompanied by inflammation of the joints and eyes.
What is psoriasis?
Psoriasis is a chronic autoimmune disease that causes red, scaly patches to appear on the surface of the skin. They are often called plates.
Psoriasis cannot be infected: it is an autoimmune, non-infectious disease.
Psoriasis is manifested by inflammation of the skin, as well as abnormally rapid growth and exfoliation of the cells (keratinocytes) that make up the stratum corneum, the epidermis. Normally it is completely renewed after a month, but in people with psoriasis this process is accelerated many times and lasts an average of 3 to 4 days.
In addition to skin damage, the disease causes inflammation of the joints (in approximately 30% of cases). A little less frequently, in 10% of cases, psoriasis causes inflammation of the uvea (uveitis).
Prevalence of psoriasis
Psoriasis most frequently affects people between 15 and 35 years old, but in general the disease can appear at any age. The first peak of the appearance of the pathology occurs between 15 and 20 years of age, the second between 55 and 60 years of age.
On average, psoriasis affects approximately 1-2% of people worldwide. In our country, according to the clinical recommendations of the Ministry of Health, in 2021 the prevalence of the disease was 243. 7 cases per 100, 000 inhabitants.
Types of psoriasis
Like many chronic diseases, psoriasis is distinguished by stages, severity and form of manifestation.
By stage
Psoriasis has three stages: progressive, stationary and regression (remission).
INprogressive stageRed spots appear on the skin. Merging, they form large scaly plaques with a pronounced red outline around the edges; It is called erythema erythematosus. Redness of the skin caused by dilation of capillaries and blood flow. corolla or corolla. New plates are very itchy and may hurt.
Traumatized areas of the skin are especially susceptible to the appearance of new spots: a psoriatic plaque can quickly develop at the site of friction (for example, on clothing), as well as in the area of a scratch or scrape. Doctors call this phenomenon Koebner's phenomenon.
This phenomenon, also known as "isomorphic reaction, " was discovered by German dermatologist Heinrich Koebner in 1872. The doctor observed that in some psoriasis patients new plaques appear on the skin at sites of trauma, for example after scratches, injections or bruises.
stationary stage- stabilization phase. The plaques stop growing, but they continue to bother and come off. New rashes or spots usually do not appear.
Regression stageIt occurs when psoriasis symptoms begin to disappear. The peeling disappears, the plaques lighten and flatten. Symptoms decrease in this phase.
By gravity
To assess the severity of psoriasis, doctors use the PASI (Psoriasis Area and Severity Index) system, an index to assess the severity and prevalence of psoriasis. It requires professional analysis of parameters such as severity of erythema, infiltration, peeling, and calculation of the area of skin affected by rashes.
Depending on the results of the examination, doctors distinguish between mild, moderate and severe degrees of the disease.
according to the shape
Depending on the clinical picture of manifestations, several main forms of psoriasis are distinguished: vulgar, inverse, seborrheic, exudative, guttate, pustular, psoriasis of the palms and soles and psoriatic erythroderma.
Psoriasis vulgaris (ordinary)- one of the most common forms and accounts for approximately 90% of all cases of the disease. First, red spots appear on the skin, which in a few days transform into convex, scaly plaques. As the plaques develop, they fuse together forming large, scaly, itchy lesions. Then the condition enters the stage of stabilization and regression: the manifestations of the disease temporarily disappear and the person's well-being improves.
The most common places where psoriasis vulgaris appears are the extensor (outer) part of the skin of the elbows and knees. Lesions also appear on the body and scalp.
Psoriasis vulgaris on the outside of the elbow.
Inverse ("inverse") psoriasisproceed in the same way as usual. The only difference is in the location of the lesions: they do not appear on the extensor (outer) part of the knees and elbows, but on the flexor (inner) part, that is, below the knee, under the armpits and in the elbow. area, as well as in the neck, eyelids, navel, inguinal folds. The skin in these places is more delicate, moist, and rubs more frequently against clothing. Because of this, it may itch more than with the usual form of the disease, but the peeling in these places is less pronounced.
Seborrheic psoriasisIt proceeds in the same way as usual, but its foci are located in places with a large number of glands that secrete sebum. These are the scalp, folds behind the ears, cheeks and nasolabial area of the face, forehead, chest and back (mainly the upper part).
Seborrheic psoriasis on the scalp
Exudative psoriasis- a type of disease in which, in addition to peeling, exudate also appears in the lesion. It is a liquid that contains proteins, some blood cells and other substances. During inflammation, exudate can be released from the capillaries.
The crust on the surface of the plaques in the exudative form of the disease is usually dense, grayish-yellow, and sometimes slightly moist. This type of psoriasis appears more frequently in people with endocrine disorders: thyroid pathologies, type 2 diabetes mellitus or obesity.
Guttate psoriasisIt does not appear as plaques on the skin, but as numerous papules: bright red swollen spots with peeling in the center. The size of the papules can vary from approximately 1 to 10 mm. They mainly cover the torso, arms and legs.
Guttate psoriasis usually appears in children after streptococcal infections (for example, tonsillitis). It is treated somewhat better than other types of psoriasis, but in some cases it can become the common (vulgar) form.
pustular psoriasisIt is characterized by the appearance of multiple pustules on an erythematous red background. Pustules are formations that look very similar to pimples. This psoriasis can be a consequence of infectious diseases, stress, hormonal imbalance, inappropriate use of medications or inappropriate use of ointments. Initially, numerous pustules appear on the red spots. They then merge into a large purulent spot (or "purulent lake").
The generalized form of pustular psoriasis is difficult to tolerate: with episodes of fever, weakness, as well as severe pain and burning of the skin. In parallel, changes in the nails and pain in the joints can be observed.
Psoriasis of palms and soles.- Typical psoriatic rashes appear in the area of the palms and soles of the feet, less often they appear in the form of localized pustular psoriasis. It can also affect and deform the nails: they become thicker, cloudy and uneven.
Psoriasis on the palm
Erythrodermic psoriasisIt is quite rare and is considered an extremely serious form of the disease. There is redness on about 90% of the body, severe itching and pain appear, the skin swells and peels. Often the temperature rises and the lymph nodes become swollen.
Typically, this type of psoriasis is the result of an exacerbation of another form of the disease due to inadequate treatment or adverse environmental factors (for example, sunburn in advanced psoriasis vulgaris, inappropriate use of external irritating agents or intravenous administration of glucocorticosteroids ).
Symptoms of psoriasis
The manifestations of psoriasis vary depending on the type of disease and its severity.
Common symptoms and signs of psoriasis:
- red, raised, scaly spots on the skin;
- itching in the area of inflammation and peeling;
- changes in the nails: point impressions, thickening and crumbling of the plate, its separation;
- joint pain (sometimes).
For an accurate diagnosis, you should contact a specialized specialist - a dermatologist.
The mechanism of development of psoriasis
Psoriasis is an autoimmune disease.
All autoimmune pathologies are associated with an error in the functioning of the immune system. Normally, it "scans" the body 24 hours a day and looks for pathogenic cells using foreign protein molecules that distinguish them from the "normal" cells inherent in the body.
As soon as foreign protein molecules are detected, the immune system activates special immune cells, T lymphocytes, which must destroy the enemy.
But for some people, the friend-foe recognition system may fail. As a result, the immune system begins to attack healthy cells of individual organs or tissues, causes inflammation in their locations and in every way harms your body, which, in fact, it should protect.
This is what happens with psoriasis: the immune system attacks the skin. It activates T lymphocytes and "fixes" them to skin cells. Upon reaching the target, T lymphocytes release substances that cause inflammation: cytokines. They cause the first symptoms: redness, swelling, itching and pain.
In psoriasis, skin cells divide several times faster, causing flaking and peeling.
Under the influence of cytokines, an inflammatory process develops and skin cells begin to actively divide; This is how active peeling occurs and a convex plaque is formed.
Since the process of cell renewal is accelerated almost ten times, the main cells of the epidermis (keratinocytes) do not have time to form properly. And therefore, they cannot perform their barrier function.
As a result, the stratum corneum becomes permeable and stops protecting the deeper layers of the skin from the environment and moisture loss. All of this leads to even more inflammation.
Until the immune system calms down, the disease will progress and symptoms will increase.
Causes of psoriasis
The exact reasons why psoriasis develops are not yet fully understood. However, many studies agree that the development of psoriasis is associated with genetics, as well as lifestyle, comorbidities, and adverse environmental factors.
Genetics
The disease is usually inherited from parents to children. Psoriasis is mainly associated with the HLA-C gene. It encodes a protein that allows the immune system to recognize its own (harmless) cells.
In patients with psoriasis, doctors detect a special genetic marker in the HLA-C gene more often than in other people: HLA-Cw6. However, its presence only indicates a predisposition to the disease. Not all people with the HLA-Cw6 marker necessarily have psoriasis and not all patients diagnosed with the disease have this genetic change.
Lifestyle
It is believed that constant damage to the skin, frequent friction, sunburn and hypothermia can be triggers for the development of the disease. Especially if there is a hereditary predisposition in the form of the HLA-Cw6 genetic marker or if there are close relatives suffering from psoriasis.
Other risk factors include constant stress, alcohol abuse and smoking; All this has a detrimental effect on metabolism, the functioning of internal organs and the immune system.
Concomitant pathologies
Some types of psoriasis, such as guttate psoriasis, can appear after a streptococcal infection.
Additionally, the risk of developing pathology increases in people with autoimmune diseases. These include, for example, type 1 diabetes, Crohn's disease, systemic lupus erythematosus, and rheumatoid arthritis.
In such diseases, the general mechanism of the immune system is disturbed: it perceives some of its own cells as something foreign, reacts with inflammation and destroys them. Consequently, the risk of you accidentally adding other cells to the "blacklist" increases.
Complications of psoriasis
Psoriasis is caused by a malfunctioning immune system and chronic systemic inflammation. It develops due to the constant aggression of immune cells towards healthy tissues.
Autoimmune processes are characterized by the fact that they can spread: the immune system is capable of including other healthy cells in the list of "enemies" at any time.
For example, in the context of psoriasis, Crohn's disease or ulcerative colitis can develop if the immune system mistakenly attacks the tissues of the gastrointestinal tract.
In addition to autoimmune diseases, people with psoriasis are susceptible to various endocrine pathologies (metabolic syndrome, obesity, type 2 diabetes), cardiovascular diseases (hypertension, heart attack) and other dysfunctions of internal organs. All of this is associated with a chronic inflammatory process, which affects hormonal levels and interferes with normal metabolism.
A separate complication is psoriatic arthritis. It occurs in approximately 30% of people with psoriasis.
In psoriatic arthritis, the immune system attacks the connective tissue and most frequently affects the joints of the lower extremities. Inflammation of the joint structures develops, the skin in the affected area may turn red, swelling appears, as well as pain and/or stiffness when trying to bend or straighten the joint.
In 10% of people with psoriasis, the pathology spreads to the eyes and uveitis develops. The choroid of the eye becomes inflamed, causing decreased vision and discomfort.
In addition to physiological complications, psoriasis can affect a person's mental health. Changes in appearance, poor skin condition and unbearable itching can cause doubts and lead to a depressive disorder.
Diagnosis of psoriasis
A dermatologist diagnoses skin diseases, including psoriasis.
At the appointment, the doctor will ask you about your symptoms and how long ago they appeared. Then you will ask your closest relatives: parents, brothers and sisters about skin diseases. The family history allows the specialist to immediately assume diseases that can be inherited: psoriasis is one of them.
The doctor will also ask about situations that cause new rashes to appear and worsening symptoms. For example, new psoriatic lesions may appear after taking a hot bath or prolonged exposure to the sun. In some patients, plaques appear at injection sites, scratches, or after rubbing the skin on clothing; This is how the Koebner phenomenon, characteristic of psoriasis, manifests itself.
An important point in establishing a diagnosis is examination of the rash. If the picture of the disease is insufficient, a specialist can observe the rash over time and prescribe a histological examination of the skin (biopsy).
If the doctor is not sure that the skin plaques are psoriasis, she will prescribe a biopsy and histological examination of the skin.
Histological examination of skin and subcutaneous neoplasms.
The study allows us to identify malignant changes in the tissues of skin tumors (moles, papillomas, warts, age spots). Material obtained through biopsy or during surgery is used for the analysis.
In some cases, a specialist can check for the psoriatic triad, the main diagnostic signs of psoriasis.
First, the dermatologist will take a glass slide or scalpel and begin to gently scrape the surface of the plaque. The slight exfoliation of whitish scales from its surface, or the stearin spot phenomenon, is the first sign of the triad.
After all the scabs have been removed, the surface of the plate becomes smooth, shiny and slightly moist. This is the second sign of the triad: the terminal film.
If the doctor continues to scratch the spot, spot bleeding will appear on its surface, which is called Auspitz syndrome or bloody spray, the third sign of the psoriatic triad.
After an examination and medical history, the doctor will prescribe laboratory tests. It is generally recommended to perform a clinical blood test, which reflects the general state of health. The patient is also referred for blood biochemistry. Allows you to evaluate the functioning of internal organs and metabolism; with a prolonged course, psoriasis can provoke pathologies of the cardiovascular and endocrine systems.
A general urinalysis is also often prescribed. Problems with the urinary system can interfere with the use of certain medications.
A general urine test includes a physical and chemical examination of urine (color, density, composition) and a microscopic examination of its sediment. A general urine analysis is prescribed to check the state of the body, to identify pathologies of the urinary system, gastrointestinal tract, endocrine, infectious and inflammatory diseases.
For the same reason, according to clinical recommendations, tests for HIV and hepatitis are prescribed. Against the background of these infections, the disease can be more serious.
Additionally, in preparation for treatment, women should take a pregnancy test, for example, a blood test for beta-hCG. The fact is that many systemic drugs, which are most often prescribed for the treatment of psoriasis and give a good effect, are contraindicated during pregnancy.
The study allows you to diagnose pregnancy in the early stages and identify its complications. In induced abortion, it is used to evaluate the effectiveness of the procedure. In oncology: for the diagnosis of hormone-producing tumors.
If you complain of joint pain, the doctor will also refer the patient for an MRI, CT scan, or X-ray to confirm or rule out psoriatic arthritis. If joint inflammation is confirmed, the dermatologist will recommend an examination by a rheumatologist.
Psoriasis treatment
If the area of affected skin is small, patients are prescribed topical corticosteroid creams or ointments. They suppress inflammation and reduce the manifestations of the disease.
Additionally, the doctor may prescribe local analogues of vitamin A or vitamin D. Such drugs relieve inflammation, accelerate the exfoliation of the stratum corneum of the skin and slow down the growth of psoriatic plaques. It is also recommended to use skin moisturizing creams from pharmacy dermatocosmetics lines.
Mild psoriasis is usually treated with ointments and creams for external use.
For moderate to severe psoriasis, systemic treatment may be necessary, in the form of classical and genetically modified immunosuppressive biological drugs in the form of tablets or subcutaneous injections. They have a pronounced effect, but require careful examination before use.
Systemic glucocorticosteroids for psoriasis are contraindicated and can only be prescribed by a doctor in certain (extremely difficult) situations and in a hospital setting. Otherwise, such treatment can lead to a significant deterioration of the condition.
Psoriasis is also treated with phototherapy: ultraviolet light of a certain spectrum is directed at the plaques. Many physiotherapy offices have special lamps for this type of treatment.
The most modern and effective way to treat psoriasis is monoclonal antibodies (genetically engineered biological therapy). These medications can block some stages of the inflammatory response, for example, certain cytokines. The proteins, which are mainly produced by the protective cells of the immune system, cause inflammation and plaque growth in psoriasis.
Psoriasis prevention
There is no specific prevention that can prevent the development of psoriasis.
In general, it is recommended to lead a healthy lifestyle: give up alcohol and tobacco, exercise and eat a healthy, balanced diet.
People whose relatives suffer from psoriasis should be more careful with their skin: moisturize it regularly, avoid hypothermia, prolonged exposure to the sun, and also avoid visiting solariums. Tattoos are not recommended if you have a hereditary predisposition to psoriasis.
Forecast
Psoriasis is a chronic pathology, like all autoimmune diseases. It is impossible to completely cure psoriasis.
However, timely and correctly selected treatment can allow the patient to achieve long-term remission, a period of asymptomatic disease.
Frequently asked questions
Psoriasis cannot be infected. It is an autoimmune disease: it occurs when a person's immune system does not work properly and mistakenly attacks skin cells. The disease has a hereditary (genetic) predisposition, which means it can be inherited.
How does psoriasis manifest?
In most cases of psoriasis, large red, scaly plaques appear on the surface of the skin. They can be very itchy and even painful. Most often, psoriatic spots appear on the elbows, knees, torso and scalp.
What doctor treats psoriasis?
A dermatologist treats psoriasis.
Can people with psoriasis be accepted into the army?
With a mild form of psoriasis, they can be assigned category B - "limitedly adequate. "A recruit with moderate or severe psoriasis may be considered unfit for military service. In each specific case, the decision is made individually during the medical examination.