Irina Alexandrovna Zborovskaya – doctor of medical sciences, professor, cathedral professor of hospital therapy with the course of clinical rheumatology of the doctors improvement faculty of Volgograd state medical university, director of the Federal Budgetary State Institution (FBSI) “Research and development institute of clinical and experimental rheumatology” of the RAMS, head of the regional Osteoporosis Center, presidium member of the Association of rheumatologists of Russia, member of the editorial boards of the magazines “Scientific and practical rheumatology” and “Modern rheumatology” Definition. Psoriasis is referred to as dermatosis, which is characterized by proliferation of the epidermis. The exact aetiology of proliferation of the epidermis is unclear. Psoriasis is clinically manifested by clearly marked pink papules with silvery scales. Psoriasis of the palms and feet, pustular psoriasis as well as skin involvement in flexion areas of extremities and skin folds occur less commonly. It is typically localized at the extensor surface of large joints such as knee and elbow, scalp, intergluteal cleft, umbilicus and sacral region.  Psoriatic nail involvement is frequently present in psoriatic arthritis. Psoriasis is a systemic disease, which is clinically manifested by either dermal or dermal-articular and visceral symptoms, depending on the extent of the disease severity. Psoriatic arthritis is one of the main forms of inflammatory diseases of the spine and joints. It is a chronic systemic progressive disease associated with psoriasis. It usually results in the development of erosive arthritis, resorption of bone (osteolysis), multiple enthesitis and spondylarthritis. In as many as 75 percent of patients psoriasis usually precedes arthritis. In 15 percent psoriatic arthritis may be present with obvious skin lesions. In other cases joint involvement appears before psoriasis. There is a group of the so-called seronegative spondylarthritis, which are referred to as diseases characterized by frequent involvement of iliosacral joints and absence of rheumatoid factor in blood serum. Family history of these disorders should also be considered. Psoriatic arthritis, Reuter’s disease, arthritis in chronic non-specific diseases of the intestine belong to this group. Ankylosing spondylitis also belongs to this subgroup. Seronegative spondylarthritis is characterized by the following clinical manifestations: 1. Negative test result for rheumatoid factor (RF) (negative test result for antinuclear factor). 2. Absence of subcutaneous rheumatoid nodules. 3. Arthritis of peripheral joints, most commonly asymmetric. 4. Radiologic evidence of sacroileitis and/or ankylosing spondylitis. 5. Clinical overlaps (“overlap” syndrome) among diseases belonging to this group. They are characterised by the following two or more features:

• Psoriasis or psoriasis-like skin or nail involvement.
• Ocular involvement, including conjunctivitis or acute anterior uveitis.
• Ulcer of the mucous membranes of the cheeks.
• Ulceration of the large or small intestine.
• Inflammatory processes in the urogenital tract, in particular urethritis and/or prostatitis.
• Erythema nodosum.
• Gangrenous pyodermia.
• Thrombophlebitis.

6. Seronegative spondylarthritis tends to run in the family. Family history of “overlap” syndromes is typically present (two and more cases of various types of spondylarthritis are usually present in the family). 7. Seronegative spondylarthritis is associated with HLA-B₂₇ histocompatibility antigen. It is suggested that patients with sacroileitis are typically HLA-B₂₇–positive.   Epidemiology. The incindence of psoriatic arthritis is rather high. Psoriasis is revealed in 1 – 3% of patients. Men and women are affected equally. Psoriatic arthritis affects 5 – 7% of patients with psoriasis. Psoriatic arthritis characteristically develops in persons aged 20 – 50 years, but it can occur in persons of almost any age. Psoriatic arthritis is less common in children. 1,9 percent of all forms of psoriasis occur in children. Psoriatic arthritis typically develops as a result of dermatosis (at the age of 3 – 4 years). The disease is usually severe and often progresses into erythroderma. Joint syndrome usually develops at the age of 9 – 12 and is typically the only manifestation of juvenile psoriatic arthritis.   Aetiology and pathogenesis. The exact aetiology and pathogenesis of psoriatic arthritis remain unknown. In recent years psoriasis and psoriatic arthritis have been considered as clinical manifestations of a systemic process as a part of psoriatic disease. Aetiologic and pathogenetic mechanisms of the development of skin psoriasis are similar to those of psoriatic arthritis. Genetic influences (that is association between HLA and psoriatic arthritis), environmental and immunological factors are thought to be prominent in the development of the disease. Leukocyte antigen system studies in patients with psoriasis made it possible to reveal two sub-types of the disease. They are the following: Psoriasis Type I is particularly associated with with HLA (about 65% of patients with psoriasis) and it is characterised by an early age of onset. Psoriasis is associated with HLA В13, В16, В17, В27, В38, В39, DR4, DR7 antigens. It has been established that HLA B27 antigen is associated with axial skeleton involvement (spine and iliosacral joints), while DR4 antigen is associated with erosive arthritis of peripheral joints. Vulgar psoriasis is associated with HLA CW6 antigen. Psoriasis Type II develops much later in life and it is not associated with HLA. Psoriasis is inherited in different ways, presumably according to autosome-dominant type with genetic component comprising 60 – 70% and an environmental one – 30 – 40 percent. The exact structure of hereditary predisposition remains unclear. It is known that genes, which are not included into HLA system, also contribute to the development of this disease. It means that psoriasis may be associated not only with the presence of “psoriasis gene” in genotype but also with a favourable allele combination of auxiliary genes (polygenic inheritance model). The onset of skin and joint syndromes can occur at an interval of some years. They usually develop separately and treatment of one of them does not effect the course of the other. However, in some cases joint and skin syndromes develop simultaneously. At the same time exacerbation of the syndromes can also be noted. That is why they should not be considered as separate processes occurring occasionally or due to genetic predisposition. The character of dermatosis effects the formation of clinical and morphological manifestations of joint syndrome and other features of joint involvement, including the rate of progression of bone and cartilage destruction, severity of disease, systemic manifestations. A mild course of skin involvement is usually associated with a favorable course of arthritis and, on the contrary, atypical forms of  psoriasis are usually associated with severe, progressive generalized joint syndrome. Thus, vulgar focal psoriasis is associated with distal or monooligoarthritic type of arthritis and prolonged preservation of joint functions. Exudative and atypical dermatosis (such as erythroderma, pustular psoriasis) are associated with the development of generalized arthritis, osteolytic and spondyloarthritic types of a progressive course of the disease. Malignant psoriatic arthritis typically develops in patients with atypical psoriasis. Immunologic disturbances play a significant role in pathogenesis of psoriatic arthritis. They include the following: T- and B-lymphocyte ratio changes, increased IgA, IgG and IgE levels and normal levels of IgM in blood serum, antibodies to antigens of the corneal and granular layers of the epidermis, accumulation of antibodies and immune complexes in the epidermis of patients with psoriasis. It has been established that in psoriatic arthritis lymphopenia with increased CD8 lymphocyte levels typically develops. However, functional activity of CD8 lymphocytes is usually decreased. Low levels of the complement and increased phagocyte activity of neutrophils and mononuclear cells are often seen in psoriatic arthritis. The development of an active process is always associated with cytokine production, increased expression of receptors to cytokines on  tissue cells. In psoriatic arthritis IL-1, tumor necrosis factor and IL-8 are typically activated resulting in a disorder of cytokine regulation of the cellular cycle. It usually causes hyperproliferation of epidermal cells, impaired keratinization, inflammation in the derma. The order of the development of a pathologic process in psoriatic arthritis may be presented in the following way. Under the influence of certain factors faulty keratinocytes usually develop in predisposed persons. Faulty keratinocytes are skin antigens activating local immunity such as phagocytes, CD4, CD8 and B-lymphocytes, natural killers which produce pro-inflammatory IL-1, TNF, IL-8 cytokines, interferons, colony-stimulating factors as well as increased expression of cytokine receptors and adhesion molecules on cell surface of the skin and other types of the connective tissue. In the course of the development of the immune reaction the antigen is partially eliminated from the body and at the same time new cells are damaged. Autoantigens usually form under certain circumstances resulting in the development of autoimmune reaction as a result of impaired natural tolerance. Sensitized lymphocytes and antibodies to autoantigens form in the body. Cytotoxic lymphocytes damage tissues of the body and circulating immune complexes with an antigen entering the blood stream typically form. Circulating immune complexes are typically eliminated by phagocytic system. However, if it fails to do it, immunocomplex tissue damage usually occurs. Pathomorphology. Histologic changes of the synovial membrane in psoriatic arthritis are similar to those in chronic synovitis. They are the following: exudative and proliferative reactions of moderate severity with predominance of fibrous changes, infiltration of the synovial membrane by fibrin, polynuclear cells and lymphocytes as well as dystrophy and necrosis of synoviocytes with subsequent desquamation of cells, capillaritis and vasculitis. Localization of inflammatory cellular infiltrate predominantly in the superficial layers of the synovial membrane is a characteristic feature of psoriatic synovitis. The development of destructive proliferative vasculitis, ring-shaped sclerosis of vascular walls as well as absence of clearly marked fibrosis of the subintimal layer of the epidermis is also typical of psoriatic arthritis. The same changes are usually seen in psoriatic plaques in skin. The process also involves epiphyseal parts of bones and articular cartilage in which erosive changes may occur. In severe cases osteolysis may develop. It usually spreads to metaepiphysial area and even futher along the bone. At the same time reparative processes usually occur. They include the development of periostitis of bones forming the impaired joint, formation of osteophytes, calcification of the ligamentous apparatus of the joint. Depending on the stage of the process the following histologic findings of psoriatic synovitis are singled out: early changes such as edema of the subsynovial layer, increased activity of alkaline phosphatase in endothelium of capillaries, capillaritis, single vasculitis, scarce diffuse infiltrate composed of lymphocytes, macrophages, polynuclear cells as well as hypertrophy and poor proliferation of synoviocytes; active progressive immuno-inflammatory process. It is typically charactersied by proliferation of synoviocytes, infiltration of the synovial layer by polynuclear cells, lymphocytes, macrophages, pronounced dystrophic changes in synoviocytes and their desquamation, fibrin masses with a great amount of lysed cells on the surface of the villi, superficial localization of the inflammatory reaction in the subsynovial layer of the villi, capillaritis,  vasculitis, angiogenesis in deep layers of the villi associated with ring-shaped sclerosis of the walls of the vessels, foci of hemosiderosis; and, finally, regression of the immuno-inflammatory process. It is charactersied by slight focal perivascular infiltration composed of lymphocytes and plasmocytes, pronounced sclerosis of the walls of the vessels and atrophy of synoviocytes. The extent of morphological changes depends on the localization of the inflammatory process and duration of the disease. The outcome of arthritis varies from subluxations and contractures to ankylosis of joints. Clinical manifestations. The onset of the disease may be acute, subacute or gradual. Sometimes prodromal period which is clinically manifested by weakness, malaise, increased fatigability, sleep disturbances, arthralgias, myalgias, fever and loss of weight, can be noted. Acute onset of the disease is typical of septic arthritis or acute attack of gout. Patients with psoriatic arthritis usually experience a severe pain during the day. It is often associated with local and general joint stiffness. These symptoms are typically associated with subfebrile body temperature and laboratory findings of an active inflammatory process. In one-third of patients joint syndrome is characterised by a gradual onset, with predominance of proliferative changes. Joint stiffness may be insignificant for a long period of time. Spontaneous remission of the disease may occur when articular syndrome disappears for some months or even years. However, most commonly psoriatic arthritis is characterised by a progressive course. Asymmetric diffuse involvement of some distal interphalangeal and metatarsophalangeal joints of feet and hands is a characteristic clinical manifestation of psoriatic arthritis. The lesions are usually multiple but at the onset of the disease asymmetric monooligoarthritis may develop. In most patients large joints such as knee, ankle and others are typically involved in the process. Sometimes subluxations of the fingers or toes and flexion contractures are seen. Palpation of joints in psoriatic arthritis is moderately painful. Swelling is usually compact and, as a rule, it spreads beoynd the bounds of the joint. The skin above the involved joint is cyanotic or purple-cyanotic. Changes of the shape of distal joints and the specific colouration of the skin usually cause “radish” or “thimble” deformities. Arthitis of distal intraphalangeal joints is usually associated with trophic changes of nails. Hyponycheal psoriatic papules, hyponycheal hyperkeratosis, onycholysis are common in psoriatic arthritis. “Axial” lesion is typical of psoriatic arthritis. Three joints of one finger such as distal, proximal intraphalangeal and metacarpophalangeal are usually involved. Ankylosis of these joints is also common. The same changes can be observed in toes. Diffuse swelling of joints due to thickening of the soft tissues as well as involvement of tendon sheaths leading to the typical “sausage” appearance (dactylitis) are common features of psoriatic arthritis. Bursitis of the Achilles tendon, subcalcaneal bursitis causing pain in the heel region (talalgia) and enthesopathy (pain in the area of  attachment of ligaments and tendons) are also common in psoriatic arthritis. 5% of patients develop a disfiguring form of psoriatic arthritis when fingers are shortened and twisted as a result of ostelolytic process. Multiple subluxations and ankylosis of joints (mutilating form) can be seen. Osteolysis usually occurs in small joints of hands and feet, including metacarpal and metatarsal joints, carpometacarpal and radiocarpal joints. Osteolysis affects not only epiphysis of bones forming the joint. True bone dystrophy typically develops in diaphysis of phalangeal, metacarpal and metatarsal bones. Sometimes complete osteolysis of metacarpal bones associated with thinning-out of bones of the forearm may occur. These changes are usually asymmetric and disordered. Flexion and extension contractures as well as dislocation of the axis of bones may be found on the same hand. The spine is often involved in patients with psoriatic arthritis. Lumbar, sacroiliac parts are most commonly involved, while cervical and thoracic parts are less commonly affected. Morning stiffness and pain in vertebrae may persist during the day. As a result the carriage is usually impaired leading to “petitioner’s posture”. Sometimes sterno-clavicular and streno-costal joints are involved. The patients usually experience pain in the chest which aggravates when coughing and inspirating. Swelling associated with clinical manifestations of Tietze’s syndrome is also common. One-third of patients develop temporomandibular joint involvement associated with limitation of the range of motion. Extraarticular features of psoriatic arthritis. Skin involvemen.: Skin involvement in psoriatic arthritis is characterised by predisposition to exudation and pustulation. It is not responsive to therapy. Rash usually appears in the area of finger tips and it is often associated with nail involvement leading to onycholysis. Cardial syndrome. Some patients complain of pain and sensation of heaviness in the precardiac area, irregular palpitation, attacks of tachycardia. ECG changes usually include rhythm and conduction disturbances, hypertrophy of heart chambers, diffuse myocardial changes, increased QT interval. Syndrome of early repolarization of ventricles is commonly seen in psoriatic arthritis. Aortitis is considered to be the most important clinical manifestation of cardiac syndrome. Dilatation of the aorta, diffuse thickening of the initial part of the aorta and focal thickening on the posterior wall of the aorta are associated with vertebral involvement. Some patients develop myocarditis. It is usually associated with an inflammatory process and it is clinically manifested by tachycardia, rhythm and conduction disturbances and diffuse changes on ECG, enlargement of the heart and changes of its configuration. However, patients with psoriatic arthritis do not develop circulatory insufficiency. Pericarditis in patients with psoriatic arthritis is usually adhesive. The symptoms are not quite obvious. It is usually diagnosed if there are pleural and pericardial adhisions. Inflammation of the aortic valve has also been reported in patients with psoriatic arthritis. Hepatopathy. The liver is typically enlarged. However, no disorder of the function of the liver is noted. The frequency of hepatic involvement does not correlate with the duration and severity of the disease. However, it is associated with disease activity and other internal organ involvement. Chronic hepatitis, cirrhosis and hepatic amyloidosis may develop in psoriatic arthritis. Poorly marked clinical manifestations of psoriatic arthritis are commonly seen. Renal syndrome. Chronic glomerulonephritis and systemic amyloidosis associated with renal involvement can occur in psoriatic arthritis. Diffuse glomerulonephritis has a quite favorable course. Sometimes it is characterised by extrarenal symptoms which do not lead to renal dysfunction for a long period of time. Renal amyloidosis leading to chronic renal insufficiency is considered to be one of the main factors which causes death in psoriatic arthritis. Amyloidosis usually has a generalized course associated with involvement of almost all internal organs. Ocular involvemen.: It is typically characterized by psoriatic blepharitis, acute anterior uveitis associated with considerable loss of vision. 31 percent of patients with psoriatic arthritis develop ocular involvement. In some patients eyes are involved simultaneously with oral mucosa and urogenital tract involvement. Nervous system involvement. Organic changes in central and peripheral nervous system, involvement of mononeurons of the anterior horns of the spinal column and ventral roots of the spinal nerve as well as demyelination of peripheral nerve fibers are commonly noted in psoriatic arthritis. Functional disturbances of the central nervous system associated with neurotic reactions are typically due to a prolonged course of the disease and its severity. Types of clinical course of the disease. Common course of the disease is characterized by inflammatory changes in certain joints, sacroiliitis and/or involvement of the upper parts of the spine which does not lead to its dysfunction. It is also characterised by destructive changes in some joints, by an inflammatory process of moderate or minimum activity, slowly progressing course of the disease, systemic clinical manifestations which do not lead to dysfunction of the involved organs, limited or diffuse vulgar psoriasis. Severe course of the disease is characterized by generalized arthritis, ankylosing spondyloarthritis with pronounced vertebral deformity, multiple erosive arthritis, lysis of bone epiphysis of two or more joints, dysfunction of joints of the second or third degree, general (for example, fever, emaciation) and visceral clinical manifestations associated with dysfunction of the involved organs, progressive exudative or atypical psoriasis, maximum extent of activity of the inflammatory process for 3 months and even more. Diagnosis of the severe course of psoriatic arthritis requires at least two of the above mentioned clinical manifestations. Malignant form has a male predominance. It typically develops in young men (under 35 years) with pustular or erythrodermic psoriasis. It is characterised by a severe course of the disease associated with  hectic fever, quick loss of body weight so that even cachexy can develop, generalized arthritis with a pronounced exudative component, spondiloarthritis, generalized lymphadenopathy and multiple visceritis. Clinical and anatomic types of psoriatic arthritis. Classic psoriatic arthritis with involvement of distal interphalangeal joints of the hands and feet (5%) is typically associated with psoriatic nail and joint involvement. Mutilating arthritis associated with sacroiliitis (5%) is one of the most severe forms of joint involvement. It is characterized by dislocation of the bones of hands and feet leading to a shortening of fingers (the so-called “lorgnette” deformity). Symmetrical polyarthritis is often erroneously taken for  rheumatoid arthritis (15 percent of cases). It is characterised by the relative asymmetry of the lesion, both proximal and distal hand, wrist, ankle, and feet involvement (which often leads to ankylosis), metacarpal, ankle, knee and elbow joint involvement, absence of subcutaneous nodules and negative test result for rheumatoid factor (RF) which is typical of rheumatoid arthritis. In asymmetrical periarticular arthritis (70 percent of cases) joints of the hands and feet are affected first, leading to the typical “sausage” appearance (dactylitis) which is associated with axial tenosynovitis of  interphalangeal joints. Monooligoarticular arthritis is characterized by inflammation of 1 – 3 joints in the remote period of the disease. Knee, elbow and shoulder involvement is typical of monooligoarticular arthritis. However, any joint can be involved, including temporomandibular, streno-clavicular and other joints. Monooligoarticular arthritis is the most common type of all (70 – 75%). It typically has a favorable course. Ankylosing spondylarthritis with or without peripheral arthritis (5%) is considered as a clinical manifestation of generalized enthezopathy. Juvenile psoriatic arthritis. Classification of psoriatic arthritis. Course of the disease:

1. Severe
2. Common (moderate and mild)

Clinical and anatomical type of articular syndrome:

1. Distal
2. Oligoarthritic
3. Polyarthritic
4. Osteolytic
5. Spondylarthritic

Systemic manifestations:

1. Without any systemic manifestations;
2. With systemic manifestations: trophic disturbances, generalized amyotrophy, polyadeny, carditis, heart failure, pericarditis, aortitis, nonspecific reactive hepatitis, hepatic cirrhosis, amyloidosis of  internal organs, skin and joints, diffuse glomerulonephritis, acute anterior uveitis, nonspecific urethritis, polyneuritis, Raynaud`s syndrome.

III. Malignant form; Phase and extent of disease activity: A)   Active

1. Minimum
2. Moderate
3. Maximum

B)   Remission Imaging studies. A)              Peripheral and axial joints

1. Periarticular osteoporosis;

IIA. Periarticular osteoporosis, narrowing of the articular space, cyst-like formations of bone tissue; IIB. Periarticular osteoporosis and  single areas of superficial bone attrition; III. Periarticular osteoporosis, multiple areas of bone attrition, intraarticular osteolysis; IV.Periarticular osteoporosis and bone ankylosis. B)              Sacroiliac joints;

1. Poorly marked articular space and unpronounced osteoporosis;
2. Narrowing or enlargement of the articular space, subchondral osteosclerosis;

III. Narrowing or enlargement of the articular space, subchondral osteosclerosis and  partial ankylosis; IV.Narrowing or enlargement of the articular space, subchondral osteosclerosis and complete ankylosis; C)              Ankylosing spondylarthritis associated with: I. Syndesmophytes or paraspinal ossificates. II. Ankylosis of intravertebral joints. Functional ability of the patient may be: A) Preserved B) Affected The patient is able to work and perform usual activities; the patient cannot work; the patient is limited in ability to perform usual self-care. The course and stage of psoriasis: A) Course

1. Vulgar: focal and diffuse
2. Exudative
3. Atypical;
4. Pustular
5. Erythrodermic
6. Psoriasis rupioides

B) Stage

1. Progressive
2. Permanent
3. Regressive

C)               Psoriasis associated with nail involvement Psoriatic spondylarthritis is characterized by formation of bone bridges between certain vertebrae as well as by vertebral and paravertebral ossificates and asymmetrical ankylosis of intervertebral joints. Lab studies. No specific diagnostic tests are available for psoriatic arthritis. In pronounced exudative arthritis an elevated ESR is usually found (to 30 mm/h); moderate leukocytosis, elevations of C-reactive protein levels, increased alfa- and gamma-globulins, normochromal anemia and antinuclear factor are typical of psoriatic arthritis. RF is not detected. The synovial fluid is inflammatory. It means that it indicates increased cytosis with a neutrophilic shift. Diagnostics. Diagnostic criteria with a score system have been suggested by the Rheumatology Institute of the Russian Academy for Medical Sciences. The use of these criteria made it possible to establish the diagnosis at an early stage of the disease. Diagnostic and differentiation criteria of psoriatic arthritis (suggested by Agababova, etc., 1989)

№	Criteria	Scores
1  2 3 4 5 6 7 8 9   10 11 12   13 14 15   16   1 2 3 4	Psoriasis  Psoriatic rash on the skin — Psoriasis associated with nail involvement; — Skin psoriasis in first-degree relatives; — Arthritis of distal interphalangeal joints of the hand; —  Arthritis of 3 joints of the same finger (axial lesion); Subluxations of fingers in different directions Asymmetrical chronic arthritis Purple colour of the skin above the involved joints with poor palpatory sensitivity «Sausage-like» deformity of toes Skin and bone involvement Pain and morning stiffness in any part of the spine for more than 3 months Seronegative rheumatoid factor Acroosteolysis Ankylosis of distal interphalangeal joints of the radiographic features of  specific  sacroiliitis Syndesmophytes or paravertebral ossificates Differentiation criteria Absence of psoriasis Seropositive rheumatoid factor Rheumatoid nodules A certain correlation between intestinal and urogenital infection.	+5 +2 +1 +1 +5 +4 +2 +5   +3 +4 +1   +2 +5 +5 +2 +4   -5 -5 -5 -5

Diagnostic rule. If the sum of the scores is 16, psoriatic arthritis is considered to be classical, 11 – 15 points – defined; 8 – 10 – possible; 7 and even less, psoriatic arthritis is unlikely.   Differential diagnosis. Psoriatic arthritis should be differentiated from the following rheumatic conditions:

• Rheumatoid arthritis
• Ankylosing spondylarthritis
• Urogenital reactive arthritis (Reiter`s syndrome)
• Gout arthritis
• SAPHO syndrome (Synovitis, Aсne, Pustulosis, Hyperostosis, Osteomyelitis) – pustulosis palmaris et plantaris, acne, purulent hydradenitis, sternoclavicular hyperostosis, chronic sterile multiple lymphadenitis, hyperostosis of the spine.

Treatment: The main objective of the treatment of psoriatic arthritis is controlling the inflammatory process in joints, achieving and maintaining remission, preventing destructive changes in joints. Initial treatment of psoriatic arthritis which is not associated with high inflammatory activity should be carried out with nonsteroidal anti-inflammatory drugs. The treatment of psoriatic arthritis usually begins with high doses of NSAIDs. The treatment is typically prolonged (2 – 6 months) and it may be even longer if pain syndrome persists. Drugs with enhanced therapeutic activity and minimum side effects should be used. Intraarticular glucocorticoids are of great importance. It should be remembered that no more than 3 injections should be given within a year. Drugs with a prolonged action are advisable. The dose depends on the size of the joint: large joints – 1 ml, middle-sized – 0.5 ml, small joints – 0.25 ml. In some cases local glucocorticoid therapy makes it possible to achieve remission of psoriatic arthritis. Systemic corticosteroids are usually avoided. Only short courses (6 – 8 weeks) of corticoids in the dose of (5 – 7.5 mg daily for prednisolone) are administered if no effect from other methods of treatment is seen. In moderately severe psoriatic arthritis administration of drugs of a prolonged action is indicated, for example, intramuscular administration of gold once a week. It should be administered 10 mg weekly for the first two weeks to evaluate the tolerance to the drug. Then the dose should be increased to 20 mg and it should be administered for 2 weeks. If the patient is tolerant of the drug, the treatment should be continued (in the dose of 50 mg weekly) until one decides on efficacy (usually 7 – 10 months). Then the dose should be gradually reduced by increasing intervals between injections to 10 days, 2 weeks, but no more than 3 weeks. Patients with severe and progressive psoriatic arthritis, especially with marked pain syndrome, disorder of the joint function and high activity of the process, which is torpid to common anti-inflammatory treatment should receive immunosuppressant agents, especially methotrexate. The first signs of a therapeutic effect are typically noticed 3 – 4 weeks after the beginning of the treatment.  Immunosuppressant agents are usually administered in the dose of 7.5 – 25 mg weekly and in case of a positive effect, the dose can be reduced to 10 – 15 mg weekly. It is not recommended to administer drugs suppressing hematosis, salicylates and anticoagulants simultaneously with methotrexate. Sulfasalazone can also be administered in patients with psoriatic arthritis. It is effective in symmetric arthritis and arthritis associated with spondylitis. It is typically administered in the dose of 2 g for adults. If no effect has been achieved after 4 months, the treatment should be discontinued. Comparative evaluation of the results of treatment, demonstrated that intramuscular administration of gold is the most effective. Derivatives of sulfasalazine rank the second and methotrexate ranks the third. Sulfasalazine turned out to be the best tolerated drug. Methotrexate and gold are equally well tolerated. Several open and 2 randomized placebo-controlled studies dealt with the use of infliximab in treating psoriatic arthritis and psoriasis which were unresponsive to standard therapy. Infliximab has shown successful results in reducing the signs and symptoms of psoriatic arthritis such as skin and joint involvement. A 20% improvement was noted in 70, 6% of patients, a 50% improvement – in 52,9% of patients, a 70% improvement was seen in 25, 5% of patients. Sometimes extracorporal photochemotherapy is used in treating psoriatic arthritis. It is a new method of immune therapy in which leucocytes of the peripheral blood, sensitized by methoxyprozalen-8 are exposed to ultraviolet irradiation and then are returned to the patient. This method is effective in a prolonged course of psoriatic arthritis. In highly severe psoriatic arthritis apheresis is used. Plasmapheresis which can be associated with intravenous ultraviolet irradiation or laser irradiation of blood is the most effective. Ointments (including steroids) are typically used locally and applied to the affected areas of the skin. Remedial exercises, physiotherapy and balneology are also administered in psoriatic arthritis. Surgical treatment. Surgical intervention has been effective in treating severe chronic synovitis and destructive changes in joints leading to a limited range of motion.   Prognosis. Evidence suggests that psoriatic arthritis may be disabling and destructive. It may also shorten patients` life. The following factors indicate an unfavorable outcome of the disease:  early age of onset, especially in childhood, HLA marker (patients with HLA-DR-3, DR-4 are more likely to experience disease progression), severe psoriasis, generalized type of the disease. Thus, treatment should be aggressive in individuals with progressive joint disease.