Epidural Abscess
A pus collection near the brain or spinal cord
Quick Facts
- Type: Serious infection of the spine or skull lining
- Location: Epidural space (outside the dura)
- Spinal warning signs: Back pain, fever, weakness, numbness
- Urgency: Medical emergency — treat immediately
Overview
An epidural abscess is a medical emergency. Prompt treatment is essential to prevent permanent nerve damage. It is a collection of pus in the epidural space, the area just outside the dura, which is the tough outer membrane covering the brain and spinal cord. The abscess can form along the spine (spinal epidural abscess) or inside the skull (intracranial epidural abscess).
A spinal epidural abscess is especially important to recognize because the growing pocket of pus and inflammation can compress the spinal cord and nerves, potentially causing weakness, numbness, and even paralysis if not treated quickly. The classic spinal warning combination is back pain, fever, and new neurological symptoms. Because the window to prevent lasting damage can be short, early diagnosis and treatment make a major difference.
Symptoms
Symptoms depend on whether the abscess is in the spine or the skull, and how much it is pressing on nearby nerves.
- Spinal epidural abscess: Severe, localized back or neck pain, fever, and tenderness over the spine. As it progresses it can cause weakness, numbness or tingling in the limbs, and problems with bladder or bowel control, which are serious warning signs.
- Intracranial epidural abscess: Fever, headache, and sometimes drowsiness, often with signs of a nearby sinus or ear infection.
- General signs: Feeling generally unwell, and symptoms of any underlying infection.
New back pain with fever, especially if accompanied by leg weakness, numbness, or loss of bladder or bowel control, is an emergency and needs immediate assessment.
Causes
An epidural abscess develops when bacteria reach the epidural space and form a pocket of pus.
- Bloodstream spread: Bacteria from an infection elsewhere, such as the skin, urinary tract, or heart valves, can travel to the spine.
- Spread from nearby infection: Infection of a vertebra or disc, or a sinus or ear infection for intracranial abscesses, can extend into the epidural space.
- Direct entry: Spinal injections, epidural catheters, spinal surgery, or injury can introduce bacteria.
- Injection drug use: A recognized route for bacteria to enter the bloodstream and seed the spine.
Risk Factors
- Diabetes
- A weakened immune system
- Injection drug use
- Recent spinal procedures, injections, or surgery
- An infection elsewhere in the body, such as a skin, bone, or bloodstream infection
- For intracranial abscesses, sinus or ear infections and head injury
Diagnosis
Imaging is central to diagnosis, and speed matters because nerve damage can become permanent.
- MRI: The best test to show the abscess, its size, and the degree of compression on the spinal cord or nerves; a CT scan may be used if MRI is not available.
- Blood tests and cultures: To confirm infection and identify the bacteria.
- Inflammatory markers: Often raised and helpful in raising suspicion.
- Cultures from the abscess: When pus is drained, to guide antibiotic choice.
Treatment
Treatment usually combines antibiotics with surgical drainage, particularly when nerves are being compressed. Urgent care is essential.
- Surgical drainage or decompression: Often needed quickly to remove the pus and relieve pressure on the spinal cord or nerves, especially when weakness or numbness is present.
- Intravenous antibiotics: Prolonged courses given through a vein, tailored once the bacteria are identified.
- Treating the source: Addressing the underlying infection that led to the abscess.
- Supportive care and rehabilitation: Pain control, monitoring, and physical therapy to recover function after treatment.
Outcomes depend heavily on how soon treatment begins; nerve damage present before treatment may not fully reverse, which is why early action is so important.
Prevention
Reducing infection risk and treating infections promptly are the main preventive steps.
- Treat infections of the skin, urinary tract, and other sites before they spread
- Manage diabetes and other conditions that weaken immunity
- Avoid injection drug use and seek support for substance use
- Follow sterile and aftercare instructions for spinal injections and surgery
- Report new severe back pain with fever promptly rather than waiting
When to See a Doctor
An epidural abscess is a medical emergency. Seek emergency care or call emergency services immediately if you have:
- New, severe back or neck pain with fever
- Weakness, numbness, or tingling in the arms or legs
- Loss of bladder or bowel control
- Rapidly worsening neurological symptoms
- For head infections: fever and severe headache, especially after a sinus or ear infection
Acting fast can prevent permanent nerve damage or paralysis.
Frequently Asked Questions
What is an epidural abscess?
It is a collection of pus in the epidural space, just outside the tough membrane covering the brain or spinal cord. A spinal epidural abscess can compress the spinal cord and nerves, making it a serious emergency.
What are the warning signs of a spinal epidural abscess?
The classic combination is severe back or neck pain with fever. Warning signs that it is compressing nerves include weakness, numbness or tingling in the limbs, and loss of bladder or bowel control. These need immediate emergency care.
What causes an epidural abscess?
Bacteria reach the epidural space through the bloodstream from an infection elsewhere, by spreading from a nearby infection of the spine, sinuses, or ear, or directly through spinal procedures, surgery, or injury. Injection drug use is a recognized risk.
How is an epidural abscess treated?
Treatment usually combines a prolonged course of intravenous antibiotics with surgery to drain the pus and relieve pressure on the nerves, especially when weakness or numbness is present. Treating the underlying infection and rehabilitation are also important.
Can an epidural abscess cause paralysis?
Yes. If a spinal epidural abscess compresses the spinal cord and is not treated quickly, it can cause permanent weakness, numbness, or paralysis. This is why new back pain with fever and any neurological symptoms must be evaluated urgently.
References
- MedlinePlus, U.S. National Library of Medicine. Spinal epidural abscess.
- National Institute of Neurological Disorders and Stroke (NINDS).
- Mayo Clinic. Spinal infections.
- Centers for Disease Control and Prevention (CDC).