A patient with a history of recurrent perianal abscesses, presenting with a tender mass and redness in the perianal area, and having a fistula with redness and fluctuation, what is the most appropriate step in management?

Examination Under General Anesthesia (EUA) with Drainage

This patient requires immediate examination under general anesthesia with incision and drainage of the fluctuant abscess—this is the definitive management and should not be delayed. 1

Why EUA with Drainage is Mandatory

The presence of a fluctuant mass indicates a collection requiring urgent surgical drainage, which is the cornerstone of treatment for all perianal abscesses. 1 The clinical examination findings alone are sufficient to proceed directly to the operating room without additional imaging. 1

Timing of Intervention

While this patient does not appear to have sepsis, immunosuppression, diabetes, or diffuse cellulitis (which would mandate emergent drainage), surgical drainage should still occur within 24 hours of presentation. 1, 2 The recurrent nature of this patient's presentations makes prompt definitive management even more critical.

Why Other Options Are Inappropriate

CT Pelvis (Option A) - Incorrect

• Examination under anesthesia with drainage should not be postponed even if pelvic imaging is unavailable when a perianal abscess is clinically suspected. 1
• Routine imaging is not required when the diagnosis is clinically evident with fluctuation on examination. 2
• Imaging may be considered later only if there is recurrence, suspected inflammatory bowel disease, or evidence of non-healing wound. 2

Oral Antibiotics with Outpatient Follow-up (Option B) - Incorrect

• Antibiotics are not routinely needed after adequate surgical drainage unless sepsis or significant cellulitis is present. 1
• A recent 2024 randomized controlled trial definitively showed that antibiotic treatment has no influence on anal fistula formation or recurrent perianal abscess after incision and drainage. 3
• Antibiotics without drainage will not resolve a fluctuant abscess collection. 1, 2

Bedside Needle Aspiration (Option C) - Incorrect

• Incision and drainage is superior to needle aspiration, with recurrence rates of 15% vs 41% respectively. 2
• Complete drainage is essential, as inadequate drainage is associated with high recurrence rates up to 44%. 2

Critical Management Principles During EUA

What TO DO:

• Perform adequate incision and drainage with complete evacuation of the abscess cavity. 1, 2
• Keep the incision as close as possible to the anal verge to minimize potential fistula length. 2
• If an obvious fistula is identified without probing, place a loose draining seton rather than laying it open. 1

What NOT TO DO:

• Do not actively probe for the fistula during acute abscess drainage to avoid creating iatrogenic tracts and complicating future management. 1, 4
• Never attempt fistulotomy during acute abscess drainage to minimize tissue disruption and preserve anal function. 1

Special Considerations for This Patient

The history of recurrent presentations with spontaneous drainage strongly suggests underlying fistula-in-ano, which occurs in approximately one-third of perianal abscess cases. 1 This makes the following essential:

• Exclude underlying Crohn's disease in every patient with recurrent anorectal abscess. 1
• Perform endoscopic evaluation of the rectum after the acute phase resolves to determine the most appropriate long-term management strategy. 1
• Counsel the patient that definitive fistula management will require subsequent treatment planning after the acute sepsis resolves, potentially including sphincter-sparing procedures. 1

Common Pitfalls to Avoid

• Delaying surgery to obtain imaging when clinical diagnosis is clear. 1
• Attempting definitive fistula surgery during acute abscess drainage. 1
• Prescribing antibiotics as primary treatment instead of surgical drainage. 1, 3
• Inadequate drainage leading to recurrence rates up to 44%. 2