Distinguishing inflammatory from noninflammatory arthritis, enthesitis, and dactylitis in psoriatic arthritis: a report from the GRAPPA 2010 annual meeting.

The most widely applied criteria for classifying psoriatic arthritis (PsA) are the CASPAR (ClASsification of Psoriatic ARthritis) criteria. A patient who fulfills the CASPAR criteria must have evidence of inflammatory arthritis, enthesitis, or spondylitis, and may have an inflammatory musculoskeletal component, dactylitis. Although the criteria were developed by rheumatologists, not all patients with PsA are seen by rheumatologists. Thus, it is important for clinicians such as dermatologists, primary care providers, physiatrists, and orthopedists, and patients themselves, to be able to recognize the presence of inflammatory musculoskeletal disease and distinguish it from degenerative or traumatic musculoskeletal disease. At their 2010 annual meeting, members of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) discussed the steps they are taking to define the key variables that must be present to distinguish inflammatory arthritis, enthesitis, and dactylitis from degenerative, traumatic, mechanical, or infectious forms of these conditions.