What is the appropriate management for a patient with a subcutaneous abscess, cellulitis, and a fistula in the scrotal area, as seen on a computed tomography (CT) scan of the pelvis?

Management of Scrotal Abscess with Fistula

For a patient with a subcutaneous abscess posterior to the left scrotum measuring 2.5x4.9x2.6 cm with a fistulous tract and bilateral cellulitis, surgical incision and drainage of the abscess is the primary treatment, along with appropriate antibiotic therapy for the surrounding cellulitis.

Diagnostic Considerations

• CT findings confirm the presence of a significant scrotal abscess (2.5x4.9x2.6 cm) with a fistulous tract extending to the scrotal skin, which requires prompt intervention 1
• The presence of bilateral cellulitis surrounding the abscess indicates soft tissue infection that requires both surgical and medical management 1
• While imaging has already been performed (CT pelvis with contrast), MRI would be the preferred imaging modality for further evaluation of complex perianal or scrotal abscesses if additional assessment is needed 1, 2

Surgical Management

• Immediate surgical incision and drainage is the cornerstone of treatment for the scrotal abscess 1, 2
• The incision should be made as close as possible to the site of maximum fluctuation while ensuring adequate drainage of the entire abscess cavity 2
• During the procedure, careful examination should be performed to identify and evaluate the fistulous tract that extends from the superolateral aspect of the abscess to the anterior aspect of the left hemiscrotal skin 1, 2
• For the identified fistulous tract:
  • If the fistula does not involve sphincter muscle (likely in this scrotal location), consider fistulotomy at the time of abscess drainage 1
  • If sphincter involvement is a concern, place a loose draining seton to maintain drainage and prevent recurrence 1, 2
• Avoid excessive probing during the procedure to prevent creation of additional iatrogenic fistulous tracts 3

Antibiotic Therapy

• Antibiotic therapy is indicated due to the presence of surrounding cellulitis 1
• For initial empiric therapy covering streptococci (common cause of cellulitis) and considering the scrotal location:
  • First-line: Cephalexin 500 mg orally four times daily or amoxicillin-clavulanate 875/125 mg twice daily 1
  • If MRSA is suspected: Add trimethoprim-sulfamethoxazole (TMP-SMX) or doxycycline 1
  • For patients requiring intravenous therapy: Cefazolin 1-2 g IV every 8 hours 1, 4
• Duration of therapy should be 5-7 days if clinical improvement occurs rapidly, or up to 14 days for more severe infections 1, 4

Post-Procedure Care

• Elevation of the affected area to promote gravity drainage of edema and inflammatory substances 1
• Regular wound care with cleaning and dressing changes to promote healing 2
• Close follow-up is essential to monitor for:
  • Resolution of infection
  • Proper healing of the surgical site
  • Potential recurrence of abscess or fistula 2, 5

Special Considerations

• Consider diabetes screening as uncontrolled diabetes is a risk factor for severe soft tissue infections and can complicate healing 1, 6
• Hospitalization may be necessary if the patient presents with:
  • Systemic inflammatory response syndrome (SIRS)
  • Hemodynamic instability
  • Immunocompromised status 4
• Pus culture should be obtained during drainage to guide targeted antibiotic therapy, especially if there are risk factors for multidrug-resistant organisms 1

Prognosis and Follow-up

• With appropriate surgical drainage and antibiotic therapy, most patients with scrotal abscesses have good outcomes 5
• Regular follow-up is needed to ensure complete resolution and to monitor for recurrence 2
• Recurrence rates can be high (up to 44%) if drainage is inadequate or if the underlying cause of the fistula is not addressed 2