Psoriatic arthritis. Current developments.

Psoriatic arthritis is a distinct rheumatologic disorder characterized by inflammatory articular involvement in patients affected with psoriasis. It occurs more commonly in Caucasians, affects both sexes, peaks in the fifth decade of life, but also occurs in children. Its pathogenesis is multifactorial in which genetic, environmental and immunologic factors seem to play important roles. Recent evidence supports an important role for fibroblast-derived cytokines and growth factors. A most interesting clinical development is the recently introduced classification of the disorder which has been simplified into three major groups: peripheral arthritis; sacroiliitis and spondylitis, and extra-articular osseous manifestations including the SAPHO syndrome. Another major advance in our understanding of the natural course of this disorder is the recognition of significant, functional limitation in approximately 11% of cases, and up to 20% of the patients may have a more severe form, often with damage to five or more joints. Methotrexate therapy has proven to be a safe and effective agent in those patients who do not respond to NSAIDs. New therapeutic modalities, including cyclosporin A and bromocriptine treatment, appear highly promising.