Should I drain a scalp cyst in an outpatient Primary Care Physician (PCP) office or refer to a specialist?

Management of Scalp Cysts in Primary Care Setting

Incision and drainage is the recommended treatment for inflamed epidermoid cysts in the primary care office, but uncomplicated scalp cysts larger than 5 cm or those with concerning features should be referred to a specialist. 1

Assessment of Scalp Cysts

When evaluating a scalp cyst, consider:

• Size of the cyst (smaller vs. larger than 5 cm)
• Signs of inflammation or infection
• Patient symptoms (pain, tenderness, drainage)
• Location and depth of the cyst
• Risk of bone involvement

Management Algorithm

Appropriate for PCP Office Management:

• Small to moderate-sized cysts (<5 cm)
• Inflamed but uncomplicated epidermoid cysts
• No signs of systemic illness
• Superficial cysts without bone involvement
• Adequate local anesthesia can be achieved

Refer to Specialist When:

• Cysts larger than 5 cm
• Deep cysts with possible bone involvement
• Multiple cysts requiring extensive excision
• Cysts in cosmetically sensitive areas
• Recurrent cysts after previous drainage
• Suspected malignant transformation
• Patient with systemic inflammatory response syndrome (SIRS)

Procedure for Office-Based Management

For inflamed epidermoid cysts appropriate for office management:

1. Incision and drainage is the recommended treatment 1
2. Gram stain and culture of pus from inflamed epidermoid cysts are not recommended 1
3. Simply covering the surgical site with a dry dressing is usually the most effective treatment of the wound 1
4. Packing the wound may cause more pain and does not improve healing compared to covering with sterile gauze 1

Antibiotic Considerations

• Systemic antibiotics are usually unnecessary unless there is:
  • Extensive surrounding cellulitis
  • Fever or other evidence of systemic infection
  • Markedly impaired host defenses 1
  • Signs of SIRS (temperature >38°C or <36°C, tachypnea >24 breaths/min, tachycardia >90 beats/min, WBC >12,000 or <400 cells/μL) 1

Special Considerations

Potential Complications

• Scalp cysts can occasionally cause bone erosion, especially with long-standing or large cysts 2, 3
• Malignant transformation is rare but possible 4
• Recurrence is common if the cyst wall is not completely removed 4

Follow-up

• For recurrent abscesses at the same site, search for local causes such as a pilonidal cyst, hidradenitis suppurativa, or foreign material 1
• Consider referral if the cyst recurs after drainage

Conclusion

While many inflamed epidermoid cysts can be safely managed in the primary care setting with incision and drainage, larger cysts (>5 cm), those with concerning features, or those in complex anatomical locations should be referred to a specialist for complete surgical excision to prevent recurrence and potential complications.