Say it 10 times fast: Seronegative Spondyloarthropaties

Today we discussed seronegative spondyloarthropathies, including Ankylosing Spondylitis.

1. Primary care referrals to rheumatology: On review and analysis of multiple publications regarding primary care referrals to rheumatology (BMJ 2012, Annals Rheum Dis 2015) the following criteria is suggested for referrals:

Patients with chronic back pain (duration ≥3 months) with back pain onset before 45 years of age should be referred to a rheumatologist if at least one of the following parameters is present:
•Inflammatory back pain 4/5:
    •(1) age at onset ≤40 years
    •(2) insidious onset
    •(3) improvement with exercise
    •(4) no improvement with rest
    •(5) pain at night (with improvement upon getting up)
•Human leucocyte antigen-B27 positivity
•Sacroiliitis on imaging, if available (on X-rays or MRI)
•Peripheral manifestations (in particular arthritis, enthesitis and/or dactylitis)
•Extra-articular manifestation (psoriasis, inflammatory bowel disease and/or uveitis)
•Positive family history for spondyloarthritis
•Good response to non-steroidal anti-inflammatory drugs
•Elevated acute phase reactants

2. Radiographic findings of the sacroiliac joints include subchondral erosions, sclerosis and proliferation primarily on the iliac side, sometimes described to appear like the edge of a postage stamp.  At endstage, the SI joint may be a thin line or invisible.

3.  In all-comers with chronic low back pain, only 1% are caused by non-mechanical causes like inflammatory arthritis. (NEJM 2001)  This AAFP article includes information regarding chronic low back pain including epidemiology, "red flags," and psychosocial "yellow flags" (which predict long term disability).