Psoriasis is a condition in which the human immune system mistakenly attacks healthy skin cells. As a result, scaly plaques appear on its surface that 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 plaques.
Psoriasis cannot be infected: it is an autoimmune disease, not an infectious one.
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 within a month, but in people suffering from psoriasis this process is accelerated many times and occurs on average in 3-4 days.
In addition to skin damage, the disease causes inflammation of the joints (in about 30% of cases). A little less often, in 10% of cases, psoriasis leads to inflammation of the uvea (uveitis).
Prevalence of psoriasis
Psoriasis most often affects people between the ages of 15 and 35, but in general the disease can appear at any age. The first peak of the onset of the pathology occurs at 15-20 years, the second at 55-60.
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 phase
Psoriasis has three phases: progressive, stationary and regression (remission) phase.
INprogressive phasered spots appear on the skin. Combining, they form large scaly plaques with a pronounced red outline around the edges - it is called erythematous erythema. Redness of the skin caused by dilation of capillaries and blood flow. corolla, or corolla. The new plaques are very itchy and can hurt.
Traumatized areas of the skin are especially susceptible to the appearance of new spots: a psoriatic plaque can quickly develop in a place of friction (for example, on clothes), as well as in the area of a scratch or scratch. Doctors call this phenomenon the Koebner phenomenon.
This phenomenon, also known as the "isomorphic reaction", was discovered by the German dermatologist Heinrich Koebner in 1872. The doctor noticed that in some psoriasis patients new plaques appear on the skin in traumatic places, for example after scratches, injections or bruises.
Stationary stage- stabilization phase. The plaques stop growing, but continue to bother and flake. New rashes and spots usually do not appear.
Regression phaseoccurs when the symptoms of psoriasis begin to disappear. The scaling disappears, the plaques lighten and flatten. Symptoms diminish at this stage.
By gravity
To evaluate the severity of psoriasis, doctors use the PASI system (Psoriasis Area and Severity Index), an index to evaluate the severity and prevalence of psoriasis. It requires professional analysis of parameters such as the severity of erythema, infiltration, desquamation and calculation of the area of skin affected by the rash.
Depending on the results of the examination, doctors distinguish between mild, moderate and severe degree of the disease.
According to the shape
According to the clinical picture of manifestations, several main forms of psoriasis are distinguished: vulgar, inverse, seborrheic, exudative, guttate, pustular, psoriasis of the palms and soles of the feet and psoriatic erythroderma.
Psoriasis vulgaris (ordinary).- one of the most common forms, accounting for about 90% of all cases of the disease. First, red spots appear on the skin, which within a few days turn into convex, scaly plaques. As the plaques develop, they coalesce into large, itchy, scaly lesions. Subsequently, the condition enters the stabilization and regression phase: the manifestations of the disease temporarily regress 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") psoriasiswe proceed as usual. The only difference lies in the localization of the lesions: they do not appear on the extensor (external) part of the knees and elbows, but on the flexor (internal) part, i. e. under 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 often against clothes. For this reason, it may itch more than in the usual form of the disease, but the peeling in these places is less pronounced.
Seborrheic psoriasisit proceeds in the same way as normal, but its foci are located in places with a large number of glands that secrete sebum. This is the scalp, the folds behind the ear, the cheeks and the nasolabial area of the face, forehead, chest and back (mainly the upper part).
Seborrheic psoriasis of the scalp
Exudative psoriasis- a type of disease in which, in addition to peeling, exudate also appears in the lesion. It is a fluid containing proteins, some blood cells, and other substances. Exudate can be released from capillaries during inflammation.
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 often 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 scaling 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 occurs in children after streptococcal infections (for example, tonsillitis). It is treated a little better than other types of psoriasis, but in some cases it can transform into the ordinary (vulgar) form.
Pustular psoriasischaracterized by the appearance of multiple pustules on a red erythematous background. Pustules are formations that look a lot like pimples. Such psoriasis can be a consequence of infectious diseases, stress, hormonal imbalance, improper use of medications or inadequate use of ointments. Initially, numerous pustules appear on the red spots. Then they merge into one large purulent spot (or "purulent lake").
The generalized form of pustular psoriasis is difficult to tolerate: it presents episodes of fever, weakness, as well as severe pain and burning of the skin. At the same time, changes in the nails and pain in the joints can be observed.
Psoriasis of the 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, dull and uneven.
Psoriasis on the palm
Erythrodermic psoriasisIt is quite rare and is considered an extremely serious form of the disease. There is redness in about 90% of the body, severe itching and pain appear, the skin swells and peels. The temperature often rises and the lymph nodes become inflamed.
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, inadequate use of external irritants 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 patches on the skin;
- itching in the area of inflammation and peeling;
- nail alterations: punctiform imprints, thickening and crumbling of the plaque, its separation;
- joint pain (sometimes).
For an accurate diagnosis, you need to contact a specialized specialist, a dermatologist.
The mechanism of development of psoriasis
Psoriasis is an autoimmune disease.
All autoimmune diseases are associated with an error in the functioning of the immune system. It normally "scans" the body 24 hours a day and searches for pathogenic cells via 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 not work. 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 damages its 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. After reaching the goal, T cells release substances that cause inflammation: cytokines. They cause the first symptoms: redness, swelling, itching and pain.
With psoriasis, skin cells divide several times faster, causing scaling 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 cell renewal process is almost tenfold, 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 ceases to protect 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, lifestyle, concomitant diseases and adverse environmental factors.
Genetics
The disease is often 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 more often than in other people detect a special genetic marker in the HLA-C gene: 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 alteration.
Lifestyle
It is believed that constant damage to the skin, frequent friction, sunburn and hypothermia may be triggers for the development of the disease. Especially if there is a hereditary predisposition in the form of the genetic marker HLA-Cw6 or 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 strep infection.
Furthermore, the risk of developing pathologies 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 disrupted: it perceives some of its own cells as something foreign, reacts with inflammation and destroys them. As a result, the risk of her mistakenly adding more cells to the "blacklist" increases.
Complications of psoriasis
Psoriasis is caused by a malfunction of the immune system and chronic systemic inflammation. It develops due to the constant aggression of immune cells towards healthy tissues.
Autoimmune processes are distinguished by the fact that they can spread: the immune system is able to include other healthy cells in the list of "enemies" at any time.
For example, against the background 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 subject to various endocrine pathologies (metabolic syndrome, obesity, type 2 diabetes), cardiovascular diseases (hypertension, heart attack) and other internal organ dysfunctions. All this is associated with a chronic inflammatory process, which affects hormone levels and interferes with normal metabolism.
A separate complication is psoriatic arthritis. It occurs in about 30% of people with psoriasis.
In psoriatic arthritis, the immune system attacks the connective tissue, most often affecting the joints of the lower limbs. Inflammation of the joint structures develops, the skin in the affected area may become red, swelling, pain and/or stiffness appear when trying to bend or straighten the joint.
In 10% of people with psoriasis, the disease spreads to the eyes and develops uveitis. The choroid of the eye becomes inflamed, resulting in 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 insecurity and lead to depressive disorders.
Diagnosis of psoriasis
A dermatologist diagnoses skin diseases, including psoriasis.
At your appointment, your doctor will ask what your symptoms are and how long ago they appeared. Then he will ask his closest relatives: parents, brothers and sisters about skin diseases. Family history allows the specialist to immediately assume diseases that can be inherited: psoriasis is one of them.
Your doctor will also ask what situations cause new rashes to appear and symptoms to worsen. 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, in scratches or after rubbing the skin on clothing: this is how Koebner's phenomenon, characteristic of psoriasis, manifests itself.
An important point in establishing a diagnosis is examining the rash. If the picture of the disease is insufficient, a specialist can observe the rash in time and prescribe a histological examination of the skin (biopsy).
If the doctor is not sure whether the plaques on the skin are psoriasis, he will order a biopsy and a histological examination of the skin.
Histological examination of cutaneous and subcutaneous neoplasms
The study allows us to identify malignant changes in the tissues of skin tumors (nevi, papillomas, warts, age spots). Material obtained through a 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 stain phenomenon, is the first sign of the triad.
After all crusts are removed, the surface of the plaque becomes smooth, shiny and slightly moist. This is the second sign of the triad: terminal film.
If the doctor continues to scratch the area, a localized hemorrhage will appear on its surface, called Auspitz syndrome, or bloody dew, the third sign of the psoriatic triad.
After an examination and medical history, the doctor will prescribe laboratory tests. It is generally recommended to carry out a clinical blood test: it reflects the general state of health. The patient is also referred for biochemical blood tests. It allows you to evaluate the functioning of internal organs and metabolism: with a long course, psoriasis can cause pathologies of the cardiovascular and endocrine systems.
A general urinalysis is also often prescribed. Disorders associated with the urinary system may interfere with the prescription of some medications.
A general urinalysis includes a physical and chemical examination of the urine (color, density, composition) and a microscopic examination of its sediment. A general urine test is prescribed to check the condition 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.
Also, in preparation for treatment, women should undergo a pregnancy test, such as a blood test for beta-hCG. The fact is that many systemic drugs, which are 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, your doctor will also refer you 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.
Treatment of psoriasis
If the affected skin area is small, patients are prescribed topical corticosteroid creams or ointments. They suppress inflammation and reduce the manifestations of the disease.
Also, the doctor may prescribe local analogues of vitamin A or vitamin D. Such drugs relieve inflammation, accelerate exfoliation of the stratum corneum of the skin and slow the growth of psoriatic plaques. It is also advisable to use skin moisturizers from pharmaceutical dermatocosmetic lines.
Mild psoriasis is often treated with external ointments and creams.
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 hospital settings. 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 practices have special lamps for this type of treatment.
The most modern and effective way to treat psoriasis is monoclonal antibodies (genetic engineering biological therapy). These drugs can block some phases of the inflammatory response, for example some cytokines. CytokinesProteins, produced mainly by protective cells of the immune system, cause inflammation and the growth of plaques in psoriasis.
Prevention of psoriasis
There is no specific prevention that can prevent the development of psoriasis.
In general, it is advisable to lead a healthy lifestyle: stop drinking alcohol and smoking, do physical activity and follow a healthy and balanced diet.
People whose relatives have psoriasis should pay more attention to 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 disease, like all autoimmune diseases. It is impossible to completely cure psoriasis.
However, timely and properly 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 itself?
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 patches appear on the elbows, knees, torso and scalp.
Which doctor treats psoriasis?
A dermatologist treats psoriasis.
Can people with psoriasis be accepted into the military?
With a mild form of psoriasis, category B can be assigned - "limitedly suitable". A conscript 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.