What happens if an infected sebaceous cyst is opened and not drained thoroughly, will it resolve on its own?

Management of Incompletely Drained Infected Sebaceous Cysts

An infected sebaceous cyst that is opened but not thoroughly drained will likely not resolve on its own and requires complete drainage to prevent recurrence and complications.

Understanding Sebaceous Cysts and Infection

• Sebaceous cysts (more accurately called epidermoid cysts) are benign encapsulated, subepidermal nodules filled with keratin material 1
• Inflammation in sebaceous cysts typically occurs as a reaction to rupture of the cyst wall and extrusion of its contents into the dermis, rather than as a primary infectious complication 2
• These cysts can become infected, requiring proper drainage and management 2

What Happens When Drainage is Incomplete

• Inadequate drainage of loculated collections is associated with high recurrence rates and treatment failure 3
• The infection may persist or worsen if the cyst contents are not thoroughly evacuated 4
• Thick, viscous abscess contents are a known predictor of drainage failure 3
• Multiloculation (multiple compartments within the cyst) can prevent complete drainage through a single incision 3

Proper Management of Infected Sebaceous Cysts

• Incision and drainage is the cornerstone of treatment for inflamed sebaceous cysts, particularly when they are draining 2
• Effective treatment entails thorough evacuation of the pus and probing the cavity to break up loculations 4
• After drainage, simply covering the surgical site with a dry dressing is usually the easiest and most effective treatment of the wound 2
• Packing the wound with gauze is not recommended as it may cause more pain without improving healing outcomes 2

When an Infected Cyst Has Been Incompletely Drained

• For inadequate drainage, consider:
  • Re-opening the incision and ensuring complete evacuation of all contents 4
  • Probing the cavity to break up any loculations or septations 4
  • Ensuring the incision is adequate in size to allow complete drainage 3
• Avoid closing the wound without adequate drainage, as this may lead to recurrent infection 2

Antibiotic Considerations

• Systemic antibiotics are usually unnecessary for inflamed sebaceous cysts unless there are signs of systemic infection 2
• Signs warranting antibiotics include: temperature >38°C or <36°C, tachypnea >24 breaths per minute, tachycardia >90 beats per minute, or white blood cell count >12,000 or <400 cells/µL 2
• If antibiotics are deemed necessary, they should be active against Staphylococcus aureus 2

Prevention of Recurrence

• For recurrent sebaceous cysts at the same site, a search for local causes such as foreign material should be conducted 2, 5
• Consider complete excision of the cyst and its wall once the acute inflammation has resolved to prevent recurrence 2, 6
• The timing of definitive excision should be after the acute inflammation has subsided 2

Common Pitfalls to Avoid

• Avoid closing the wound without adequate drainage 2
• Do not routinely prescribe antibiotics unless there are signs of systemic infection 2
• Underestimating the viscosity of cyst contents can lead to selection of inappropriate drainage methods 3
• Attempting multiple inadequate drainage procedures increases the risk of complications 3