Psoriatic arthritis: update on pathophysiology, assessment and management.

Psoriatic arthritis (PsA) is classified as a spondyloarthropathy and characterised by synovitis, enthesitis, dactylitis and spondylitis usually manifesting as skin and nail psoriasis. Our understanding about the PsA disease state, its genetics, pathophysiology and comorbidities, as well as the ability to assess and treat the disease, has advanced as a result of significant collaborative efforts by rheumatologists and dermatologists in the development of classification criteria, outcome measures to assess the various clinical domains, and treatment trials with agents also used for diseases such as rheumatoid arthritis (RA) and psoriasis. Biological agents, especially the antitumour necrosis factors, have demonstrated significant efficacy and reasonable safety in all clinical domains of the disease, resulting in amelioration of clinical symptoms, inhibition of structural damage and improvement of function and quality of life. Although there is considerable overlap with RA, there are some differences in pathophysiology and approach to assessment and management that are important to consider. This paper reviews these subjects, with an emphasis on recent data.