Psoriatic arthritis – classification, diagnostic and clinical aspects

From 5% to 40% patients with psoriatic skin lesions develop psoriatic arthritis, but 15% to 30% of patients with psoriasis suffer from undiagnosed psoriatic arthritis. The key role in development o-f psoriasis is played by T-lymphocytes and release of proinflammatory cytokines, interferon and adhesive proteins. Infection may exert an influence on psoriasis vulgaris and psoriatic arthritis development. The presence of antibodies against the antigens of Yersinia spp., Campylobacter spp. and Chlamydia trachomatis was more frequently observed in the serum of patients with psoriatic arthritis. Diagnosis of psoriatic arthritis may be based on CASPAR criteria. Diagnostic imaging (CT, MRI, USG) are routine diagnostic procedures in psoriatic arthritis. Several sub-types of psoriatic arthritis have been identified. Questionnaires to identify early stages of the disease have been constructed. Genetic factors, cigarette smoking, alcohol abuse, infections, stress and environmental factors may affect clinical course and results of treatment of psoriasis vulgaris and psoriatic arthritis. In severe cases, the disease may lead to disability.