Ankylosing spondylitis is a chronic inflammatory arthritis that mainly affects the spine and the sacroiliac joints, and it often starts in young adults. Over time the inflammation can fuse the vertebrae and stiffen the back.
Key symptoms
- Low back pain and stiffness for more than 3 months, starting before age 45
- Morning stiffness over 30 minutes that improves with exercise, not rest
- Night pain and alternating buttock pain
- Heel pain, a painful red eye or swollen large joints
What you find on exam
- Reduced lumbar bending on the modified Schober test
- Reduced chest expansion
- Tenderness over the sacroiliac joints
- Stooped posture in advanced disease; check the eyes for uveitis
Tests
- X-ray of the sacroiliac joints: sacroiliitis
- MRI of the sacroiliac joints if the X-ray is normal
- HLA-B27, CRP and ESR
- Spine X-ray in late disease: bamboo spine
Treatment basics
- NSAIDs such as naproxen as first-line therapy
- Daily exercise and physical therapy for posture and motion
- TNF inhibitors such as adalimumab, or IL-17 inhibitors such as secukinumab, if NSAIDs fail
- Stop smoking; treat uveitis and other related problems
Red flags
- Painful red eye with blurred vision
- New neck or back pain after minor trauma in a fused spine
- Numbness, weakness or bladder problems
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.