Management Differences Between Abscesses and Cysts

For abscesses, incision and drainage is the primary treatment, while cysts typically do not require drainage unless infected or symptomatic. 1

Abscess Management

Abscesses are collections of pus within the dermis and deeper skin tissues, usually painful, tender, and fluctuant red nodules often surrounded by erythematous swelling 1
Abscesses are typically polymicrobial, containing bacteria that constitute normal regional skin flora, often combined with organisms from adjacent mucous membranes 1

Simple superficial abscesses or boils:
- Incision and drainage is the primary treatment
- Antibiotics are generally not needed 1
- To be considered a simple abscess, induration and erythema should be limited only to a defined area and should not extend beyond its borders 1
Complex abscesses (perianal, perirectal, IV drug injection sites):
- Incision and drainage is the primary treatment
- Antibiotic therapy is recommended if:
  - Systemic signs of infection are present
  - Patient is immunocompromised
  - Source control is incomplete
  - Significant cellulitis surrounds the abscess 1
- Empiric broad-spectrum antibiotics covering Gram-positive, Gram-negative, and anaerobic bacteria are recommended for complex abscesses 1

For abscesses, thorough evacuation of pus and probing the cavity to break up loculations is essential 1
Large abscesses should be drained with multiple counter incisions rather than a long incision to prevent step-off deformity and delay in wound healing 1
Simply covering the surgical site with a dry dressing is usually effective, though some clinicians pack it with gauze 1

Research suggests abscesses greater than 0.4 cm in depth from the skin surface may require drainage, while those less than 0.4 cm in depth may be safely treated with antibiotics alone 2
Larger abscesses (>5 cm) may require more aggressive management, including surgical intervention in some cases 1

Epidermoid cysts (often erroneously labeled "sebaceous cysts") contain skin flora in cheesy keratinous material 1
Inflammation and purulence in cysts typically occur as a reaction to rupture of the cyst wall and extrusion of contents into the dermis, rather than as a primary infectious complication 1

Uninfected/asymptomatic cysts:
- Many cysts that are not infected remain asymptomatic and resolve spontaneously without intervention 3
- Observation is appropriate for asymptomatic cysts 1, 3
Infected cysts:
- When a cyst becomes infected (essentially becoming an abscess), incision and drainage is indicated 1
- For specific types like Bartholin duct cysts, drainage is recommended when larger than 2 cm as they do not tend to resolve spontaneously and can recur 3

For echinococcal cysts, special precautions must be taken as cyst rupture or spillage of contents can result in anaphylaxis 1
For complex cysts that communicate with other structures (e.g., biliary system), surgical cystectomy may be required 1

Primary intervention:
- Abscesses: Almost always require drainage 1
- Cysts: Often can be observed unless infected or symptomatic 1, 3
Antibiotic use:
- Abscesses: Simple abscesses typically don't require antibiotics after drainage; complex abscesses often need broad-spectrum coverage 1
- Cysts: Antibiotics are not indicated for uninfected cysts 1
Follow-up considerations:
- Abscesses: May require close follow-up to ensure complete resolution and to address any underlying cause 4
- Cysts: May be monitored for potential growth or infection but often require no specific follow-up if asymptomatic 3

Failing to differentiate between a simple abscess (requiring only drainage) and a complex abscess (requiring drainage plus antibiotics) 1
Misdiagnosing entities such as mycotic aneurysms as simple abscesses 4
Inadequate drainage leading to recurrence or spread of infection 4
Treating all cysts as if they were abscesses, leading to unnecessary procedures 1
Not recognizing when a cyst has become infected and requires drainage 1, 3