Pathogenesis and Risk Factors for Spinal Epidural Abscess

Introduction to Spinal Epidural Abscess

The development of spinal epidural abscess occurs through three primary mechanisms: hematogenous spread, direct extension from adjacent structures, and iatrogenic inoculation, as reported by the Infectious Diseases Society of America 1, 2

Skin infections serve as a primary source of hematogenous spread, particularly in patients with a history of intravenous drug use, according to the Infectious Diseases Society of America 1, 2
Urinary tract infections represent another common origin of hematogenous spread, as noted by the Infectious Diseases Society of America 1, 2
Oral cavity and dental infections can seed the epidural space hematogenously, as reported by the Infectious Diseases Society of America 1, 2
Mastoid and middle ear infections may spread via the bloodstream to the epidural space, according to the Infectious Diseases Society of America 1, 2
Pulmonary infections occasionally serve as the source of hematogenous spread, as noted by the Infectious Diseases Society of America 1, 2

Vertebral osteomyelitis frequently extends into the epidural space, as reported by the Infectious Diseases Society of America and the European Society of Nuclear Medicine 1, 2, 3
Discitis can progress to involve the epidural compartment, according to the Infectious Diseases Society of America and the European Society of Nuclear Medicine 1, 2, 3

Spinal surgery carries a 2-3% infection risk with instrumentation, as noted by the American College of Radiology 4
Epidural anesthesia and pain injections can introduce pathogens directly into the epidural space, as reported by the Infectious Diseases Society of America 1, 2
Lumbar puncture rarely causes epidural abscess, according to the Infectious Diseases Society of America 1, 2
Spinal biopsy procedures pose an infection risk, as noted by the Infectious Diseases Society of America 1, 2
Penetrating trauma provides direct inoculation of pathogens into the epidural space, as reported by the Infectious Diseases Society of America 1, 2

Aerobic gram-negative bacilli occur particularly after procedures, as noted by the Infectious Diseases Society of America 1, 2
Anaerobes are frequently involved, especially in polymicrobial infections, according to the Infectious Diseases Society of America 1, 2
Nocardia, mycobacteria, and fungi represent rare causes of spinal epidural abscess, as reported by the Infectious Diseases Society of America 1, 2