Dangerous causes of back pain: AAA, cauda equina syndrome, epidural abscess.
Young person with back pain needs to be evaluated for injection drug use (major risk factor).
Patient with focal neurologic deficits (FND) require an MRI. Patients without FND can be screened with ESR and CRP. An ESR < 20 & CRP < 1 can effectively rule out epidural abscess as it has a 90% sensitivity for epidural abscess.
Treatment is IV antibiotics and surgical debridement.
Davis DP et al. Prospective evaluation of a clinical decision guideline to diagnose spinal epidural abscess in patients who present to the emergency department with spine pain,Journal of Neurosurgery: Spine. 2011. 14:765-770.