What is the treatment for a keratinous cyst?

Treatment of Keratinous Cysts

The most effective treatment for keratinous cysts (epidermoid cysts) is complete surgical excision with removal of the entire cyst wall to prevent recurrence. 1

Understanding Keratinous Cysts

Keratinous cysts, also known as epidermoid cysts, are benign lesions that contain cheesy keratinous material. They are often erroneously labeled as "sebaceous cysts." These cysts typically contain normal skin flora even when uninflamed. When inflammation occurs, it's usually due to rupture of the cyst wall and extrusion of its contents into the dermis, rather than an infectious complication. 1

Treatment Options

Primary Treatment: Surgical Excision

• Complete excision: The gold standard treatment involves removing the entire cyst including its wall 2
• Surgical margins: For well-defined cysts, excision with a small margin of normal tissue is sufficient 1
• Technique: The procedure involves:
  • Incision
  • Thorough evacuation of cyst contents
  • Probing the cavity to break up loculations
  • Complete removal of the cyst wall

Alternative Approaches for Specific Situations

• Retroauricular cysts: Modified excision technique has shown good to excellent results for cysts in this location 3

• Cosmetically sensitive areas:

  • CO₂ laser marsupualization - vaporizing the prominent surface of the cyst to avoid linear scarring 4
  • Two-step approach for large cysts or those in areas of cosmetic concern:
    1. Create a small hole with laser to remove contents
    2. Remove cyst wall with minimal excision about 1 month later 5

• Infected cysts:

  • Traditional approach: Incision and drainage
  • Alternative approach: Excision of infected tissue along with rim of healthy tissue followed by primary closure 6

Post-Procedure Care

• Wound management: Simply covering the surgical site with a dry dressing is usually the easiest and most effective treatment 1
• Alternative wound care: Some clinicians pack the wound with gauze or suture it closed 1
• Suture removal: If primary closure is performed, sutures are typically removed on day 14 for limbs and day 21 for the back 6

When to Consider Antibiotics

Systemic antibiotics are rarely necessary for keratinous cyst treatment. Exceptions include: 1

• Multiple lesions
• Cutaneous gangrene
• Severely impaired host defenses
• Extensive surrounding cellulitis
• Severe systemic manifestations of infection (e.g., high fever)

Potential Complications

• Low complication rate of approximately 2.2% with surgical treatment 2
• Main risk is recurrence if the cyst wall is not completely removed 2

Key Points for Success

• Complete removal of the cyst wall is essential to prevent recurrence 2
• Most procedures can be performed under local anesthesia 2
• For inflamed cysts, treatment addresses the inflammatory reaction rather than an infection 1

The surgical approach should be tailored based on cyst location, size, and whether inflammation or infection is present, but complete removal remains the cornerstone of successful treatment.