[Psoriatic arthritis. Treatment outcome parameters].

Psoriatic arthritis (PsA) has increasingly attracted the attention of clinical research in recent years with regard to long-term clinical registries, studies on epidemiology, genetics, and therapy. However, the methodology for assessing disease activity, damage and progression, as well as the resulting definition of treatment outcome parameters have progressed far less in PsA as compared to other rheumatic diseases such as rheumatoid arthritis (RA). Most of the assessment methodologies have been adapted from clinical trials on RA, ankylosing spondylitis, or psoriasis, but have not yet been validated for use in PsA. This article gives an overview of general rheumatological and PsA-specific assessment methods and outcome parameters of PsA therapy.