INTRODUCTION

Although the combination of an acute febrile illness and focal weakness should always raise the possibility of spinal epidural abscess, there are other critical diagnoses that may present similarly. The physical exam can often help localize a lesion to the brain, spinal cord, nerve root(s), peripheral nerve(s), neuromuscular junction, or muscles. While select laboratory testing may help stratify the risk of epidural abscess in a given patient, emergent imaging is indicated in any patient with signs, symptoms, and risk factors suggestive of the diagnosis.

EPIDEMIOLOGY

Spinal epidural abscess is a rare disorder, accounting for 0.2–20 per 10,000 hospital admissions. Reported risk factors include diabetes mellitus, intravenous (IV) drug use, prior spine surgery, trauma, and alcohol abuse. Spinal epidural abscess has been documented as a potential complication of epidural catheter placement and epidural injection of steroids or local anesthetics. As many as 5% of patients with epidural abscess may have a recent history of epidural anesthesia. More unusual risk factors include duodenolumbar fistula, bacterial endocarditis, and a recent history of tattooing.

Staphylococcus aureus is the most common causative organism in epidural spinal abscesses, reported in 65–73% of patients. Other important agents include Streptococcus species and Escherichia coli. Cases have been reported with a wide range of other bacterial species, and more unusual causes include Nocardia, Brucella, Cryptococcus, and Aspergillus. Specific agents may be associated with particular clinical settings.