What is the initial treatment for a patient presenting with a pilonidal abscess or inflamed cyst?

Initial Treatment of Pilonidal Abscess or Inflamed Cyst

Incision and drainage is the definitive treatment for pilonidal abscess, and antibiotics are generally not required unless systemic signs of infection are present. 1, 2

Primary Treatment: Incision and Drainage

The cornerstone of management for pilonidal abscess is surgical drainage, which should not be delayed. 1, 2

Drainage Technique

• Perform incision and drainage with thorough evacuation of all pus and probe the cavity to break up any loculations. 1, 2
• Simply cover the surgical site with a dry sterile dressing - this is usually the easiest and most effective wound treatment. 1
• Avoid packing the wound with gauze, as one study found packing caused more pain without improving healing compared to just covering with sterile gauze. 1
• For larger abscesses, use multiple counter-incisions rather than one long incision to prevent step-off deformity and delayed healing. 2

Enhanced Drainage Options

• Curettage of the abscess cavity during drainage may be superior to simple drainage alone, as it is associated with faster healing (96% vs 78.7% healed within 10 weeks) and significantly lower recurrence rates (11% vs 42%). 3
• Definitive excision of the epithelial sinus tracts at the time of acute abscess drainage can be performed and may reduce recurrence, though this is more complex than simple drainage. 4

When to Add Antibiotics

Antibiotics are NOT routinely needed after adequate drainage in most cases. 1, 2

Indications for Antibiotic Therapy

Add antibiotics only if the patient demonstrates systemic inflammatory response syndrome (SIRS) criteria: 1, 2

• Temperature >38°C or <36°C
• Tachycardia >90 beats/minute
• Tachypnea >24 breaths/minute
• White blood cell count >12,000 or <4,000 cells/µL

Also consider antibiotics if: 1, 2

• Patient has markedly impaired host defenses (immunocompromised)
• Significant surrounding cellulitis is present
• Source control is incomplete

Antibiotic Selection (When Indicated)

• First-line oral options: Cephalexin 500 mg every 6 hours or dicloxacillin 500 mg every 6 hours 2
• If MRSA suspected or penicillin allergy: Clindamycin 300-450 mg every 6-8 hours 2
• Duration: 5-7 days based on clinical response 2, 5

Alternative Approach: Aspiration (Selected Patients Only)

Needle aspiration followed by oral antibiotics (cefalexin and metronidazole for 7 days) can be effective in 83% of carefully selected patients and is associated with high satisfaction rates. 6

Exclusion Criteria for Aspiration

Do NOT attempt aspiration if the patient has: 6

• Immunosuppression
• Diabetes
• Overlying skin necrosis
• Perforation of the abscess

Important Caveat

Aspiration is NOT recommended for most cutaneous abscesses - a randomized trial showed aspiration was successful in only 25% of cases overall and <10% with MRSA infections. 1 The pilonidal abscess study represents a specific exception in carefully selected patients. 6

Culture Considerations

• Gram stain and culture of pus from inflamed epidermoid cysts are NOT recommended. 1
• However, for pilonidal abscesses requiring drainage, culture can be reasonable to guide antibiotic therapy if systemic treatment becomes necessary. 1

Post-Procedure Wound Care

• Daily sitting in a warm tub with douche is recommended postoperatively to promote healing. 3
• Hair removal from the area is essential to prevent recurrence, as pilonidal disease results from hair penetration beneath the skin. 7
• Most patients can return to work 7-10 days after treatment. 3
• Initial healing typically occurs within 2 months. 3

Critical Pitfalls to Avoid

• Do not treat with antibiotics alone without drainage - the abscess collection requires mechanical evacuation. 1, 2
• Do not delay drainage while waiting for laboratory results - drainage is the priority therapeutic intervention. 2
• Avoid simple drainage without addressing the underlying sinus tracts if you want to minimize recurrence risk - consider curettage or definitive excision. 3, 4

Follow-Up and Recurrence

• Re-evaluate at 7 days, and if signs of infection persist beyond this timeframe, diagnostic re-evaluation is warranted. 2, 5
• Recurrence after simple drainage can exceed 40%, which is why curettage or definitive treatment may be preferred even in the acute setting. 3, 7
• Patients with incomplete wound healing beyond 10 weeks require reassessment. 3