Inflammatory spinal disease in psoriatic arthritis: a report from the GRAPPA 2010 annual meeting.

Diagnosing axial disease in patients with psoriatic arthritis (PsA) has been largely dependent on identifying inflammatory back pain (IBP), which itself has been difficult to define. We review the criteria used to identify IBP in patients with ankylosing spondylitis (AS) and other forms of spondyloarthritis. Recently, the Ankylosing SpondyloArthritis International Society (ASAS) developed a list of clinical and radiographic criteria for identifying IBP in patients with AS. However, it is more difficult to identify IBP in patients with PsA because generally they have less pain than patients with rheumatoid arthritis or AS. Further, PsA patients may have clinical symptoms of pain but negative radiographs. It may be more useful to identify sacroiliitis or syndesmophytes by magnetic resonance imaging (MRI), since MRI identifies lesions in the sacroiliac joints and the spine much earlier than can be detected on radiographs. In summary, all patients with PsA should be assessed for axial involvement with history, physical examination, and imaging. Patients with psoriasis whose history includes onset of back pain before age 40 years, the presence of night pain, and improvement with exercise but not with rest, or who have limited neck or back mobility, should be referred to a rheumatologist.