You can now download VisualDx for your iOS and Android devices. Launch the VisualDx app from your device and sign in using your VisualDx personal account username and password.
CME Certification
Sign in with your personal account to earn and claim CME credits through VisualDx. Credits can be earned by building a differential or looking up a diagnosis.
David Adelson MD
Christine Ahn MD
Carl Allen DDS, MSD
Brandon Ayres MD
Howard P. Baden MD
Robert Baran MD
Keira Barr MD
Gregory J. Basura MD, Ph.D
Donald Belsito MD
Jeffrey D. Bernhard MD
Jesse Berry MD
Victor Blanco MD
Benjamin R. Bohaty MD
William Bonnez MD
Sarah Brenner MD
Robert A. Briggaman MD
Robert Brodell MD
Roman Bronfenbrener MD
Walter Brooks MD
William Buckley MD
Philip Bulterys MD, PhD (candidate)
Susan Burgin MD
Sonya Burton MD
Sean P. Bush MD, FACEP
Jeffrey Callen MD
Scott Camazine MD
Michael Cardwell
Shelley D. Cathcart MD
Robert Chalmers MD, MRCP, FRCP
Chia-Yu Chu MD, PhD
Flavio Ciferri MD
Maria Rosa Cordisco MD
Noah Craft MD, PhD
John T. Crissey MD
Harold E. Cross MD, PhD
Charles E. Crutchfield III MD
Adriana Cruz MD
Donna Culton MD, PhD
Bart J. Currie MBBS, FRACP, DTM&H
Chicky Dadlani MD
Alexander Dane DO
C. Ralph Daniel III MD
Thomas Darling MD, PhD
William Delaney MD
Damian P. DiCostanzo MD
Ncoza Dlova MD
Erin Doudt
James Earls MD
Libby Edwards MD
Melissa K. Egge MD
Charles N. Ellis MD
Rachel Ellis MD
David Elpern MD
Nancy Esterly MD
Stephen Estes MD
E. Dale Everett MD
Janet Fairley MD
David Feingold MD
Jennifer J. Findeis-Hosey MD
Benjamin Fisher MD
Henry Foong MBBS, FRCP
David Foster MD, MPH
Brian D. Foy PhD
Michael Franzblau MD
Vincent Fulginiti MD
Sunir J. Garg MD, FACS
Kevin J. Geary MD
Lowell Goldsmith MD, MPH
Sethuraman Gomathy MD
Bernardo Gontijo MD, PhD
Kenneth Greer MD
Kenneth G. Gross MD
Alan Gruber MD
Nathan D. Gundacker MD
Akshya Gupta MD
Vidal Haddad MSC, PhD, MD
Edward Halperin MD, MA
Ronald Hansen MD
John Harvey
Rizwan Hassan MD
Michael Hawke MD
Jason E. Hawkes MD
Peter W. Heald MD
David G. Hicks MD
Sarah Hocker DO
Ryan J. Hoefen MD, PhD
Li-Yang Hsu MD
William Huang MD
Eric F. Ingerowski MD
Sanjana Iyengar MD
Alvin H. Jacobs MD
Saagar Jadeja MD
Shahbaz A. Janjua MD
Joshua J. Jarvis MD
Kit Johnson
Zachary John Jones MD
Robert Kalb MD
Katherine Kaproth-Joslin MD, PhD
Philip J. Katzman MD
A. Paul Kelly MD
Henry Kempe MD
Loren Ketai MD
Sidney Klaus MD
Ashwin Kosambia MD
Jessica A. Kozel MD
Carl Krucke
Mario E. Lacouture MD
Joseph Lam MD
Alfred T. Lane MD
Edith Lederman MD
Nahyoung Grace Lee MD
Pedro Legua MD, PhD
Robert Levin MD
Bethany Lewis MD
Sue Lewis-Jones FRCP, FRCPCH
Taisheng Li MD
Christine Liang MD
Shari Lipner MD, PhD
Adam Lipworth MD
Jason Maguire MD
Mark Malek MD, MPH
Jere Mammino DO
Ricardo Mandojana MD
Lynne Margesson MD
Thomas J. Marrie MD
Maydel Martinez MD
Ralph Massey MD
Patrick McCleskey MD
Karen McKoy MD
Thomas McMeekin MD
Josette McMichael MD
Somchai Meesiri MD
Joseph F. Merola MD
Mary Gail Mercurio MD
Anis Miladi MD
Larry E. Millikan MD
Dan Milner Jr. MD
Zaw Min MD
Stephanie Montero
Alastair Moore MD
Keith Morley MD
Dean Morrell MD
Samuel Moschella MD
Rehan Naseemuddin MD
Taimor Nawaz MD
Vic Newcomer MD
John Nguyen MD
Matilda Nicholas MD
Thomas P. Nigra MD
Steven Oberlender MD, PhD
Maria Teresa Ochoa MD
Daniel C. Oppenheimer MD
Art Papier MD
Lawrence Parish MD
Tanner Parrent MD
Mukesh Patel MD
Lauren Patty-Daskivich MD
David Peng MD, MPH
Robert Penne MD
Nitipong Permpalung MD
Miriam Pomeranz MD
Doug Powell MD
Harold S. Rabinovitz MD
Christopher J. Rapuano MD
Sireesha Reddy MD
Angela Restrepo MD, PhD
Bertrand Richert MD, PhD
J. Martin Rodriguez, MD, FACP
Theodore Rosen MD
Misha Rosenbach MD
Scott Schiffman MD
Robert H. Schosser MD
Glynis A. Scott MD
Carlos Seas MD, MSc
Deniz Seçkin MD
Daniel Sexton MD
Paul K. Shitabata MD
Tor Shwayder MD, FAAP, FAAD
Daniel Siegel, MD
Elaine Siegfried MD
Gene Sienkiewicz MD
Christye Sisson
Jonathan Soh MD
Philip I. Song MD
Mary J. Spencer MD, FAAP
Lawrence B. Stack MD
Sarah Stein MD
William Van Stoecker MD
Frances J. Storrs MD
Erik J. Stratman MD
Lindsay C. Strowd MD
Erika Summers MD
Belinda Tan MD, PhD
Robert Tomsick MD
Hensin Tsao MD, PhD
Richard P. Usatine MD
Jenny Valverde MD
Vishalakshi Viswanath MD
Susan Voci MD
Lisa Wallin ANP, FCCWS
Douglas Walsh MD
Ryan R. Walsh MD
George Watt MD
Clayton E. Wheeler MD
Sally-Ann Whelan MS, NP, CWOCN
Jan Willems MD, PhD
James Henry Willig MD, MPH
Kelly Wilmas MD
Karen Wiss MD
Vivian Wong MD, PhD
Sook-Bin Woo MS, DMD, MMSc
Jamie Woodcock MD
Stephen J. Xenias MD
Nathaniel Yohannes
Lisa Zaba MD
Vijay Zawar MD
Bonnnie Zhang MD
Carolyn Ziemer MD
Jeffrey P. Zwerner MD, PhD
Organizations
Am. Journal of Trop. Med & Hygiene
Armed Forces Pest Management Board
Blackwell Publishing
Bugwood Network
Centers For Disease Control and Prevention
Centro Internacional de Entrenamiento e Investigaciones Mèdicas (CIDEIM)
Dermatology Online Journal
East Carolina University (ECU), Division of Dermatology
International Atomic Energy Agency
Massachusetts Medical Society
NYU Department of Dermatology
Oregon Health & Science University (OHSU)
Oxford University Press
Radiological Society of North America
Washington Hospital Center
Wikipedia
World Health Organization
Epidural abscess refers to an inflammatory mass or localized collection of purulent material between the dura mater and the overlying skull in intracranial epidural abscess or the vertebral column in spinal epidural abscess (SEA).
Pathophysiology and Etiology Microbial pathogens may enter the epidural space via:
Contiguous spread from vertebral osteomyelitis or psoas abscess (about 30% of cases)
Hematogenous dissemination (about 25% to 50% of cases)
Direct inoculation (eg, during spinal or epidural anesthetic procedures or surgery)
The mechanism is unknown in the remainder of cases.
Local extension of infection from the spinal epidural space can occur or can disseminate to other sites via the bloodstream.
As the pyogenic process progresses longitudinally in the epidural space, damage to the spinal cord can be from one or a combination of factors:
Direct compression
Thrombosis and thrombophlebitis of nearby veins
Arterial blood supply interruption
Bacterial toxins and inflammatory mediators
Staphylococcus aureus causes about 50% to 90% of cases. There has been an increasing proportion of methicillin-resistant S. aureus (MRSA) cases recently, although it had historically only accounted for 15% of staphylococcal spinal epidural infections.
Less common pathogens:
Coagulase-negative staphylococci, such as Staphylococcus epidermidis, are usually related to spinal instrumentation.
Aerobic gram-negative rods, such as Escherichia coli, often arise from an infection in the urinary tract.
Pseudomonas aeruginosa is associated with IV drug users.
Other rare etiologic agents are anaerobic bacteria, agents of actinomycosis or nocardiosis, mycobacteria, fungi, or parasites (ie, Echinococcus and Dracunculus).
Polymicrobial infection occurs in about 5% to 10% of cases.
Demographics The median age of onset of SEA is approximately 50 years, and the prevalence appears to be greatest between age 50 and 70, but SEA can occur at any age. The incidence has been higher in males in some studies.
Predisposing medical history:
Diabetes mellitus
Malignancy
Human immunodeficiency virus (HIV) infection
Alcohol use disorder
Renal insufficiency
Risk factors:
Spinal abnormality, injury, or intervention – degenerative joint disease, trauma, surgery, drug injection, placement of epidural stimulators or catheters, nerve acupuncture, epidural analgesia, nerve block
Potential local or systemic source of infection – skin and soft-tissue infections, vertebral osteomyelitis, urinary tract infection, sepsis, indwelling vascular access infections, tattooing, intravenous drug use
Signs, Symptoms, and Timeline The clinical findings in patients with SEA may develop acutely within hours to days (usually after hematogenous seeding), or more chronically over weeks to months (usually in association with vertebral osteomyelitis or another contiguous focus of infection).
The initial manifestations are often nonspecific. The classical diagnostic triad consists of fever, spinal pain, and neurologic deficits. However, only some patients, 2% to 37%, have all three components at presentation.
Fever occurs in 60% to 70% of patients, but may be infrequent (range 32% to 70%). The specific neurologic signs depend on the level of spinal cord involvement.
Pain is the most consistent symptom (70% to 90% of cases) and is usually accompanied by local tenderness at the affected level.
The clinical course in most patients with SEA progresses through four clinical stages:
Stage 1 – Backache at the level of the affected spine
Stage 2 – Nerve root pain
Stage 3 – Spinal cord dysfunction
Stage 4 – Paralysis
Once paralysis develops, it may quickly become irreversible. Thus, urgent intervention may be required if progression of weakness or other neurologic findings is suspected or detected.
Epidural abscesses that are enclosed within the bony confines of the skull or spinal column can expand and cause increased intracranial pressure in the brain or compressive symptoms in the spinal cord, leading to severe symptoms, permanent complications, or even death, depending on the site of central nervous system involvement.
Intracranial Epidural Abscess
Cranial epidural abscess occurs less commonly than SEA.
Fever and headache are the usual complaints, but patients may also be asymptomatic.
Gradenigo's syndrome can occur when the cranial epidural abscess is near the petrous bone involving cranial nerves V and VI. Unilateral facial pain and weakness of the lateral rectus muscle are observed.
The initial focus is usually in the paranasal sinuses, middle ear, or mastoids, where the causative organisms are likely to be microaerophilic or anaerobic streptococci and/or other anaerobes such as Propionibacterium and Peptostreptococcus species.
Intracranial epidural abscess (IEA) may also occur after trauma, fetal scalp monitoring, halo pin penetration, and craniotomy, where the most likely infecting organisms are staphylococci, especially S. aureus, and gram-negative bacteria
Codes
ICD10CM: G06.1 – Intraspinal abscess and granuloma
SNOMEDCT: 61974008 – Epidural Abscess
Look For
Subscription Required
Diagnostic Pearls
Subscription Required
Differential Diagnosis & Pitfalls
Disk and degenerative bone disease – Back pain typically not associated with fever.
Metastatic tumors – Rapidly progressive tumors may be difficult to distinguish from SEA. Occur in the thoracic vertebra in 60% of cases. May be suggested by imaging but usually require biopsy for diagnosis.
Vertebral discitis (diskitis) and osteomyelitis – Frequently associated with SEA, and a drainable focus of infection may be missed.
Guillain-Barré syndrome (GBS) / acute demyelinating polyradiculoneuropathy – Severe low back pain, as well as bowel and bladder dysfunction and hyporeflexia that can be found in spinal cord impairment in SEA can be differentiated by the absence of a focal enhancing spinal mass lesion in acute immune-mediated polyneuropathies. Cerebrospinal fluid (CSF) analysis in GBS frequently demonstrates albuminocytologic dissociation.
Herpes zoster – Can present with unilateral pain prior to the appearance of skin lesions.
Amyloidosis and parathyroid-associated vertebral destruction – Causes of destructive lesions of the vertebra in long-term hemodialysis patients that can present with paresis or paralysis; lesions on MRI are dense and water-poor.
