Abstract
BACKGROUND: Psoriatic arthritis (PsA) is a chronic inflammatory joint disease which develops in patients with psoriasis. The rheumatoid factor is characteristically absent in the serum of PsA patients. Etiology of the disease is still unclear but a number of genetic associations have been identified. Inheritance of the disease is multilevel and the role of environmental factors is emphasized. Immunology of PsA is also quite complex. Inflammation is caused by immunological reactions leading to a release of kinins. Destructive changes in bones usually appear after a few months from the onset of clinical symptoms. MATERIAL/METHODS: PsA typically involves joints of the axial skeleton with an asymmetrical patern. The spectrum of symptoms includes inflammatory changes in attachments of articular capsules, tendons, and ligaments to bone surface. The disease can have a diverse clinical course but usually manifests as oligoarthritis. RESULTS: Imaging plays an important role in the diagnosis of PsA. Classical radiography has been used for this purpose for over a hundred years. It allows to identify late stages of the disease, when bone tissue is affected. In the last 20 years however many new imaging modalities, such as ultrasonography (US), computed tomography (CT) and magnetic resonance (MR), have been developed and became important diagnostic tools for evaluating rheumatoid diseases. They enable the assessment and monitoring of early inflammatory changes. CONCLUSIONS: As a result, patients have earlier access to modern treatment and thus formation of destructive changes in joints can be markedly delayed or even avoided.