What is the appropriate treatment for buttock infections or abscesses?

Treatment of Buttock Infections and Abscesses

The primary treatment for buttock abscesses is prompt surgical incision and drainage, with antibiotics indicated only when there are systemic signs of infection, immunocompromise, incomplete source control, or significant surrounding cellulitis. 1

Diagnosis and Assessment

Clinical Evaluation

• Pain is the most common symptom of buttock abscesses
• Physical examination should include:
  • Inspection for swelling, erythema, and fluctuance
  • Digital rectal examination (may require sedation due to pain)
  • Assessment for systemic signs of infection (fever, tachycardia)
  • Evaluation for possible underlying conditions (Crohn's disease, diabetes)

Laboratory Testing

• Not routinely required for simple abscesses
• Indicated when systemic infection is suspected:
  • Complete blood count
  • Inflammatory markers (CRP, procalcitonin)
  • Blood glucose and HbA1c (to rule out undiagnosed diabetes) 1

Imaging

• Not routinely needed for superficial abscesses
• Consider imaging for:
  • Atypical presentation
  • Suspicion of deep or supralevator abscesses
  • Complex fistulas
  • Suspected underlying Crohn's disease
• Preferred modalities:
  • MRI (highest sensitivity for anorectal abscesses)
  • CT scan (more readily available in emergency settings)
  • Endosonography (operator-dependent) 1

Treatment Algorithm

Simple Buttock Abscesses

1. Incision and drainage is the definitive treatment
   • No antibiotics needed for uncomplicated cases
   • Induration and erythema should be limited to the abscess area 1

Complex Buttock Abscesses

1. Surgical drainage remains the cornerstone of treatment

   • Large abscesses should be drained with multiple counter incisions rather than a single long incision to prevent step-off deformity and delayed healing 1
   • Timing of surgery should be based on severity of sepsis 1

2. Antibiotic therapy is indicated for:

   • Systemic signs of infection/sepsis
   • Immunocompromised patients
   • Incomplete source control
   • Significant surrounding cellulitis 1

3. Antibiotic selection:

   • Empiric broad-spectrum coverage for Gram-positive, Gram-negative, and anaerobic bacteria
   • Consider MRSA coverage in high-risk areas or patients
   • Adjust based on culture results when available 1

Perianal and Perirectal Abscesses

1. Prompt surgical drainage to prevent spread to adjacent spaces
2. Fistula evaluation during drainage:
   • For low fistulas not involving sphincter muscle: consider primary fistulotomy
   • For fistulas involving sphincter muscle: place loose draining seton
   • Avoid probing for non-obvious fistulas to prevent iatrogenic complications 1

Special Considerations

Intravenous Drug Users

• Higher risk of polymicrobial infections
• Consider potential sources: patient's oropharynx, skin, feces, or environmental contamination
• Evaluate for endocarditis if persistent systemic signs
• Rule out foreign bodies (broken needles) with radiography
• Screen for viral infections (HIV, HCV, HBV) 1

Immunocompromised Patients

• Lower threshold for antibiotic therapy
• More aggressive surgical approach
• Consider broader antimicrobial coverage 1

Outpatient Management

• Consider for fit, immunocompetent patients with small perianal abscesses without systemic signs of sepsis 1

Pitfalls and Caveats

1. Delayed diagnosis can lead to spread of infection and systemic complications
2. Misdiagnosis - buttock pain may also be caused by:
   • Nerve entrapment (sciatic, gluteal, pudendal nerves) 2
   • Spondyloarthritis (especially in patients with inflammatory bowel disease) 3
   • Vascular injuries (in cases of trauma) 4
3. Inadequate drainage leading to recurrence
4. Failure to identify and treat underlying conditions (diabetes, Crohn's disease)
5. Overuse of antibiotics for simple abscesses where drainage alone is sufficient

Remember that symptoms may be diminished in elderly, debilitated, diabetic, or immunocompromised patients, requiring a higher index of suspicion and more aggressive approach 1.