Presentation, epidemiology, diagnosis and treatment of spinal epidural abscess (SEA) and intracranial epidural abscess (ICEA) are reviewed by researchers at The John's Hopkins University School of Medicine, Baltimore, MD, and Universidad de Santander, Columbia. Risk factors for SEA have increased in frequency and include injected-drug use, diabetes mellitus, invasive spinal procedures, spinal trauma, immunosuppression, skin infections, and bacteremia. The most common risk factor for ICEA is frontal sinusitis; 60-90% of cases are associated with otitis or sinusitis. Other factors include post-traumatic infections, nasal or mastoid surgical procedures, and congenital defects of the anterior cranial fossa. Gram-positive cocci, including Staphylococcus and Streptococcus are the most common causes of SEAs, with Staph aureus involved in 50-66% of cases. Mycobacterium tuberculosis is common in some geographic areas. Pseudomonas species are isolated from injected drug users with SEA. ICEAs are polymicrobial in origin, most commonly anaerobic gram-positive cocci, Staph and Strep spp (Strep anginosis) and gram-negative bacilli. CT and MRI are the preferred diagnostic tests. Medical and surgical treatments are reviewed in detail. Morbidity and mortality from SEA are high, especially in developing countries. Early diagnosis, specific microbiologic identification and prompt antimicrobial therapy can improve prognosis. In addition to broad-spectrum antibiotics, surgery is usually required in treatment of ICEAs. 
COMMENT. Prevalence of SEA although rare has increased, as a result of injected-drug users, while that of ICEA has decreased, following the introduction of more effective antimicrobial treatments. Prognosis is often poor due to delayed diagnosis. An awareness of the common risk factors leads to early recognition and prompt antimicrobial therapy. Most common causative factors are injected-drug use, immunosuppression and spinal surgical procedures in patients with SEA, and frontal sinusitis in ICEA.