Etiology and pathogenesis
The exact causes of the disease are unknown, but the role of genetic factors has been established: in 40% it is possible to identify a complicated family history. The association of psoriatic arthritis with certain genetic loci is widely known (HLA-B27, HLA-DR4, HLA-DR7, HLA-Cw6 and others).Clinical picture
Psoriatic arthritis usually debuts after skin psoriasis (~ 10 years later). The defeat of nail plates is noted in 80% of cases. Characterized by enthesitis: inflammation of the tendon sheaths, in the first place - muscle flexors. The joint process has the character of asymmetric oligoarthritis, the distal interphalangeal joints are more often affected. Often, gross deformations of the joints (mutilating arthritis) and axial arthropathy are noted.
In many patients, a characteristic thickening of the fingers - dactylitis - is revealed.
Differences from rheumatoid arthritis for the spread of the joint process:
Diagnostics
Specific diagnostic studies for psoriatic arthritis do not exist.Among the laboratory indicators, the increase in the rate of erythrocyte sedimentation and the C-reactive protein attracts attention. Rheumatoid factor and antinuclear antibodies, as a rule, are not detected, therefore psoriatic arthritis is classified as seronegative. It is advisable to assign radiological studies (X-ray, computed tomography, magnetic resonance imaging).
Treatment
The recommendations of the European League Against Rheumatism (EULAR) on the pharmacotherapy of psoriatic arthritis look like this:
- Non-steroidal anti-inflammatory drugs (ibuprofen, naproxen and others) are prescribed as symptomatic painkillers.
- By analogy with rheumatoid arthritis, funds are available that modify the disease (methotrexate, sulfasalazine, leflunomide and etc.). It is expedient to prescribe them early in patients with active disease.
- Possible appointment of intra-articular glucocorticoids; systemic glucocorticosteroids should be used with great care, in the lowest possible doses.
- If the above-described drugs are ineffective, a drug from the anti-TNF group (infliximab, adalimumab and etc.).An additional indication for the appointment of the latter is the presence of symptoms of enthesitis, dactylitis and axial arthropathy, which can not be controlled with non-steroidal anti-inflammatory drugs or steroids.
Today, completely new effective drugs for the treatment of psoriatic arthritis are introduced into clinical practice: for example,
secuquinumab (antagonist IL-17A) and
aprimilast (inhibitor of phosphodiesterase-4).