Treatment of Inflamed Epidermoid Cysts
The definitive treatment for an inflamed epidermoid cyst is incision and drainage, with antibiotics reserved only for specific situations such as systemic inflammatory response syndrome (SIRS) or markedly impaired host defenses. 1
Primary Treatment Approach
- Incision and drainage (I&D) is the cornerstone of treatment for inflamed epidermoid cysts 2, 1
- The procedure involves:
- Making a small incision (2-3 mm) over the cyst
- Thorough evacuation of the pus
- Probing the cavity to break up loculations
- Covering the surgical site with a dry dressing
Important Technical Considerations
- Complete removal of the cyst wall is essential to prevent recurrence 1, 3
- For optimal results, the entire cyst capsule should be extracted through the incision
- Using gauze or a splatter shield during the procedure is recommended to protect from spraying of cyst contents 4
When to Use Antibiotics
Antibiotics are not routinely necessary for inflamed epidermoid cysts 2, 1. They should be reserved for:
- Presence of systemic inflammatory response syndrome (SIRS)
- Patients with markedly impaired host defenses
- Extensive surrounding cellulitis
- Multiple lesions
- Cutaneous gangrene
- Severe systemic manifestations of infection (e.g., high fever)
When antibiotics are indicated, options include:
- First-line oral: dicloxacillin, cephalexin, or clindamycin
- Alternative oral: trimethoprim-sulfamethoxazole, doxycycline
- For MRSA coverage: vancomycin
- For MSSA coverage: nafcillin/oxacillin
Standard duration is 7-10 days for uncomplicated infections, extending to 14 days for more severe cases 1.
Timing Considerations
- For severely inflamed cysts, it may be preferable to postpone complete excision until inflammation has subsided 4
- Initial I&D can help manage acute inflammation, with definitive excision performed later
Prevention of Recurrence
- Complete surgical excision with removal of the entire cyst wall is recommended for non-inflamed epidermoid cysts to prevent recurrence 1
- A minimum 4-mm margin around the cyst border should be maintained during excision 1
- Recurrence rates range from 2.2-8.3% depending on the technique used 1, 3
Post-Procedure Care
- Keep the wound clean and dry
- Monitor for signs of infection
- Schedule follow-up to assess wound healing (typically within 7-14 days)
Special Considerations
- Histopathological examination is warranted if the cyst has suspicious features such as:
- Size greater than 1.5 cm
- Rapid growth
- Nodular mass
- Ulceration
- Extensive scarring
- Fixation to surrounding tissues 1
Despite the common practice among both primary care physicians and dermatologists to prescribe antibiotics for inflamed epidermoid cysts 5, current guidelines clearly indicate that antibiotics should be reserved for specific situations as outlined above.