Review symptoms and history of inflammatory back pain
Check for morning stiffness lasting more than 30 minutes
Assess improvement with exercise and worsening with rest
Ask about alternating buttock pain
Examine for reduced spinal mobility and chest expansion
Look for peripheral arthritis, enthesitis, or dactylitis
Check for eye inflammation, psoriasis, or inflammatory bowel disease
Order blood tests for inflammation markers such as ESR and CRP
Test for HLA-B27
Obtain imaging of the sacroiliac joints and spine
Use X-rays to look for sacroiliitis and structural changes
Use MRI to detect early inflammation if X-rays are normal
Apply clinical criteria and imaging findings together
Refer to a rheumatologist for confirmation