Treatment for Inflamed Cyst
Incision and drainage is the cornerstone treatment for an inflamed cyst, and antibiotics are generally unnecessary unless systemic signs of infection are present. 1, 2
Primary Treatment: Incision and Drainage
Perform incision and drainage as the definitive first-line treatment for any inflamed cyst. 1, 2 This mechanical intervention addresses the fundamental problem—evacuation of inflammatory contents—which antibiotics alone cannot accomplish. 2
Proper Drainage Technique
- Thoroughly evacuate all purulent material and keratinous debris from the cavity. 1, 3
- Probe the cavity to break up any loculations or septations to ensure complete drainage and prevent treatment failure. 1, 3
- Cover the wound with a simple dry sterile dressing after drainage. 1
- Do not pack the wound with gauze—one study demonstrated this causes more pain without improving healing outcomes. 1
When Antibiotics Are NOT Needed
Systemic antibiotics are unnecessary in most cases of inflamed cysts after adequate drainage. 1, 2 The inflammation typically results from rupture of the cyst wall and extrusion of contents into the dermis, rather than true bacterial infection. 1, 2
Skip antibiotics when all of the following are present: 1, 2
- Temperature <38°C (or <38.5°C)
- Heart rate <90-110 beats per minute
- Respiratory rate <24 breaths per minute
- White blood cell count <12,000 cells/µL
- Erythema extending <5 cm from the incision site
- No systemic signs of infection
Research supports this approach: nearly 47% of mild inflamed cysts cultured show no bacterial growth or only normal flora. 4
When Antibiotics ARE Indicated
Add systemic antibiotics to incision and drainage only when: 1, 2
- Temperature ≥38°C (or ≥38.5°C)
- Tachycardia >90-110 beats per minute
- Tachypnea >24 breaths per minute
- White blood cell count >12,000 or <400 cells/µL
- Erythema extending >5 cm from the lesion with induration
- Patient is severely immunocompromised
- Incomplete source control after drainage
- Multiple lesions or extensive surrounding cellulitis
Antibiotic Selection
When antibiotics are necessary, choose agents active against Staphylococcus aureus, particularly MRSA in community-acquired infections: 1, 2
- Trimethoprim-sulfamethoxazole
- Clindamycin
- Doxycycline
Treat for 5-10 days based on clinical response. 2
Culture Recommendations
Do NOT routinely obtain Gram stain and culture from inflamed sebaceous cysts—they typically contain normal skin flora and inflammation is not primarily infectious. 1, 2 This distinguishes inflamed cysts from simple abscesses, where cultures may be reasonable though not mandatory. 2
Definitive Management for Recurrence Prevention
Consider complete excision of the cyst and its wall once acute inflammation resolves if recurrent infections occur at the same site. 1, 3 One study demonstrated that one-stage excision of inflamed sebaceous cysts (when appropriately selected) decreased antibiotic exposure, reduced morbidity, and proved more economical than conventional staged treatment. 5
Search for retained foreign material or cyst contents in cases of recurrent problems at the same location. 1, 3
Expected Healing Timeline
Most wounds should heal within 2-3 weeks with simple dry dressing changes after proper drainage. 3 Persistent drainage beyond this timeframe indicates inadequate initial treatment—most commonly incomplete evacuation of contents or failure to break up loculations. 3
Critical Pitfalls to Avoid
- Never prescribe antibiotics without adequate drainage—antibiotics alone will fail to resolve the mechanical problem. 3, 2
- Never close the wound without ensuring complete drainage—this leads to recurrent infection. 1, 3
- Never assume ongoing drainage beyond 2-3 weeks is normal healing—this indicates treatment failure requiring re-drainage. 3
- Never pack the wound unnecessarily—this increases pain without improving outcomes. 1, 3