Psoriatic arthritis (psoriatic arthropathy) is an inflammatory lesion of the joints associated with the cutaneous form of psoriasis. Disease is characterized by the presence of skin plaques, arthralgia, stiffness of the joints, pain in the spine, myalgia, subsequent deformation of the vertebrae and joints. Psoriatic arthropathy is diagnosed mainly by clinical and radiological signs. Treatment is carried out for a long time and systematically with the help of anti-inflammatory, vascular agents, chondroprotectors, physiotherapy, rehabilitation measures. The progressive course leads to disability of the patient.
Meaning
Psoriatic arthritis accompanies the course of psoriasis in 5-7% of patients; less often, the arthritis clinic precedes skin manifestations. The etiological factors are unknown. Among the causes, autoimmune and genetic mechanisms, environmental factors, in particular, infections are considered. The hereditary theory of this disease is supported by the identification of articular syndrome in 40% of the closest relatives of patients with psoriasis. The inclusion of immune reactivity mechanisms in pathology is confirmed in laboratory tests. It is assumed that viral and bacterial agents are involved in the development of psoriatic arthritis.
Factors predisposing to the occurrence of psoriatic arthropathy include the presence of confirmed psoriasis, hereditary predisposition, age from 30 to 50 years.
Classification
Five forms of the clinical course are classified:
- oligoarthritis with asymmetric joint involvement;
- arthritis affecting distal interphalangeal joints;
- rheumatoid-like symmetrical arthritis;
- a mutating form of arthritis with severe irreversible joint deformity;
- spondylitis.
Psoriatic arthritis symptoms
In most patients (70%), the articular syndrome develops after the skin manifestations of psoriasis; in other cases (about 20%), it precedes skin damage; in the remaining 10%– the appearance of skin and joint symptoms coincides in time. Pathology can develop gradually with general weakness, arthralgia, myalgia, or suddenly with acute arthritis with sharp pains and swelling of the joints. In the initial period, there is an interest in the interphalangeal joints of the fingers, metatarsal and metacarpophalangeal, knee, shoulder joints.
Joint pain in this disease is stronger at rest and at night; characteristic morning stiffness and pain decrease during the day and when moving. Oligoarthritis with asymmetric joint involvement is the most common clinical form. It is characterized by a lesion of no more than 4 joints of the feet and hands, “sausage-like” swelling of the fingers, the development of tendovaginitis of the flexors, purplish-cyanotic coloration of the skin above the joints. Arthritis affecting the distal interphalangeal joints is characterized by the most typical psoriatic arthritis clinic.
Rheumatoid-like symmetrical arthritis captures from 5 or more joints (interphalangeal, metacarpophalangeal); leads to disorderly deformation of the joints and multidirectional long axes of the fingers. The mutating form of psoriatic arthritis causes subluxations, irreversible deformation and shortening of the toes and hands due to osteolysis of small bones. This variant of the course of psoriatic arthritis is often found in patients with severe skin symptoms and is combined with spondyloarthritis. Spondylitis is a form of psoriatic arthritis affecting various parts of the spine. Psoriatic spondylitis can be observed in isolation or in combination with damage to the joints of the extremities.
Various variants of the course can be accompanied by muscle and fascial pain, acromioclavicular and sternoclavicular lesions, joints, achillobursitis, eye damage (iridocyclitis, conjunctivitis), less often – amyloidosis of the kidneys. Malignant development of psoriatic arthritis includes severe lesions of the skin and spine, generalized polyarthritis and lymphadenopathy, hectic fever, cachexia, involvement of visceral organs, eyes, nervous system.
Diagnostics
If psoriatic arthritis is suspected, the patient needs to consult a rheumatologist and a dermatologist.
Specific criteria for the diagnosis of psoriatic arthritis are: the involvement of the toes and hands with simultaneous damage to several joints; diffuse swelling and deformation of the fingers; defeat of the first toes; talalgia; psoriatic plaques on the skin and nail changes; cases of familial psoriasis; the presence of radiological signs; manifestations of sacroiliitis; negative test for rheumatoid factor. A mandatory criterion is the psoriatic history of the patient or relatives.
In peripheral blood with psoriatic arthritis, leukocytosis, hypochromic anemia, an increase in ESR is determined; in venous blood, an increase in the level of sialic acids, seromucoid, fibrinogen, γ– and α2-globulins is detected. Psoriatic arthritis is characterized by a negative result of a blood test for RF, the detection of immunoglobulins in the synovial membranes and skin, an increase in blood levels of IgA and IgG, and the determination of the CEC. The study of synovial effusion reveals increased cytosis and neutrophilosis, looseness of the mucin clot, low viscosity of the articular fluid.
Joint radiography in psoriatic arthritis reveals erosion of the articular surface of the bone concerned, a decrease in the width of the articular gap; signs of osteoporosis, osteolysis with misalignment of the finger bones, ankylosis of the joints, paravertebral calcification. If necessary, arthroscopy and diagnostic puncture of the joint are performed.
Psoriatic arthritis treatment
There is no specific therapy for psoriatic arthritis, and therefore treatment is focused on reducing the phenomena of inflammation, pain and preventing loss of joint function. NSAIDs (diclofenac, piroxicam, indomethacin, ibuprofen) serve as the main drugs for psoriatic arthritis. In case of their poor tolerability, complications from the kidneys, gastrointestinal tract, exacerbation of cutaneous psoriasis, it is advisable to prescribe selective COX-2 inhibitors (meloxicam, nimesulide, celecoxib). Pronounced stiffness of the joints is eliminated by the appointment of muscle relaxants (tolperizone hydrochloride, baclofen, tizanidine).
Systemic therapy includes the use of glucocorticoids. To achieve a rapid and pronounced effect (reduction of pain, increase in the amplitude of movements), intra-articular administration of glucocorticosteroids is possible. The basic drugs that modify the course of psoriatic arthritis include methotrexate, leflunomide, sulfasalazine, colchicine, mycophenolate mofetil, etc. The mechanism of their action is aimed at preventing damage to healthy joints. Basic drugs are used in conjunction with NSAIDs under the control of tolerability. In severe forms of psoriatic arthritis, immunosuppressive therapy is performed with azathioprine, cyclosporine; monoclonal antibodies to TNF-α – infliximab, etanercept.
The use of extracorporeal hemocorrection (plasmapheresis, hemosorption, membrane plasmapheresis, etc.), as well as UVI in psoriatic arthritis is indicated to reduce the activity of the disease, increase remission periods, and shorten the duration of drug treatment.
An effective physiotherapeutic method for psoriatic arthritis is PUVA therapy (photochemotherapy), which includes oral administration of a photosensitizing drug followed by external irradiation with UV rays. In the complex of physiotherapy treatment for psoriatic arthritis, sessions of magnetotherapy, transcutaneous laser therapy, electrophoresis, phonophoresis with glucocorticosteroids, dimethyl sulfoxide, exercise therapy are conducted. Gross deformities and ankylosis with irreversible disorders of joint functions are indications for joint replacement.
Prognosis and prevention
The course of psoriatic arthritis is chronic with a high probability of disabling outcome. Modern methods of therapy make it possible to achieve remission and reduce the rate of progression of the disease. The prognosis is burdened by the development of psoriatic arthritis in childhood and young age, a severe form of cutaneous psoriasis, polyarticular lesions.
Due to the unexplored etiology of psoriatic arthritis, it is impossible to prevent the disease. The measures of secondary prevention include systematic anti-relapse therapy and medical control in order to preserve the functionality of the joints.