What causes a paraspinal abscess?

From the Guidelines

Paraspinal abscesses are primarily caused by bacterial infections, with the most common causative organisms being Staphylococcus aureus, Streptococcus species, and gram-negative bacteria such as Escherichia coli, as well as fungal infections like coccidioidomycosis in immunocompromised patients 1. The infections typically originate from contiguous spread from adjacent structures like vertebral osteomyelitis, discitis, or epidural abscesses, or through hematogenous spread from distant infection sites 1. Risk factors for paraspinal abscesses include:

• Immunocompromised states (diabetes, HIV, chronic steroid use)
• Intravenous drug use
• Recent spinal procedures or surgeries
• Penetrating trauma to the back
• Tuberculosis is an important cause in endemic regions, producing cold abscesses through direct extension from vertebral bodies (Pott's disease) 1. Less commonly, fungal infections may cause paraspinal abscesses in immunocompromised patients, with coccidioidal abscesses in the muscle and epidural space being more liquid than their bacterial counterpart and often amenable to image-guided needle aspiration 1. Prompt diagnosis and treatment with appropriate antibiotics and often surgical drainage are essential to prevent complications such as spinal cord compression, neurological deficits, and systemic sepsis 1. It is crucial to monitor patients' clinical response to treatment and follow-up values for systemic inflammatory markers to identify patients at greater risk for treatment failure 1. In cases of suspected treatment failure, obtaining additional tissue samples for microbiologic and histopathologic examination, either by image-guided aspiration biopsy or through surgical sampling, may be necessary to confirm the diagnosis and guide further management 1.

From the Research

Paraspinal Abscess Causes

• Bacterial infections are a common cause of paraspinal abscesses, with Staphylococcus aureus being the most likely pathogen 2, 3, 4.
• Other bacteria, such as Klebsiella pneumoniae, can also cause paraspinal abscesses 5.
• The source of infection can be from various sources, including:
  • Cervical vertebra osteomyelitis/discitis that expands to the epidural space 5.
  • Complicated pyelonephritis due to S. aureus 2.
  • Epidural analgesia in labor 3.
• Risk factors for developing paraspinal abscesses include:
  • Diabetes mellitus 2, 4.
  • Immune system compromise 4.
  • Older age (>70 years) 4.
  • Adrenal insufficiency 4.
  • Methicillin-resistant S. aureus (MRSA) infection 4.