What is the treatment for cysts on the scalp?

Treatment of Scalp Cysts

Incision and drainage is the primary treatment for inflamed epidermoid cysts on the scalp, with complete evacuation of contents and probing to break up loculations, followed by covering with a dry dressing. 1, 2

Primary Management Approach

For Inflamed/Symptomatic Cysts

• Perform incision and drainage as the definitive treatment, ensuring thorough evacuation of the cheesy keratinous material and probing the cavity to break up any loculations 1, 2
• Cover the surgical site with a dry dressing rather than packing with gauze, as packing causes more pain without improving healing 1
• Do NOT obtain Gram stain or culture of pus from inflamed epidermoid cysts, as this is not recommended even when they appear infected 1, 3

Antibiotic Use (Rarely Needed)

Systemic antibiotics are NOT routinely indicated for inflamed scalp cysts unless specific complications are present 1, 2, 3:

• Temperature >38°C or <36°C
• Tachycardia >90 beats per minute
• Tachypnea >24 breaths per minute
• White blood cell count >12,000 or <400 cells/µL
• Multiple lesions
• Extensive surrounding cellulitis
• Severely impaired host defenses
• Cutaneous gangrene

When antibiotics are needed, use agents active against MRSA if systemic inflammatory response syndrome (SIRS) is present 1

Definitive Surgical Excision

For Asymptomatic or Recurrent Cysts

• Complete surgical excision with removal of the entire cyst wall is the first-line definitive treatment to minimize risk of recurrence 4, 5
• Early excision is recommended rather than conservative management, as it prevents complications from cyst growth and potential bone erosion (particularly with dermoid cysts in children) 5
• Excision is safe even in young patients and prevents adverse effects from untreated cysts 5

Surgical Techniques for Scalp Location

• Elliptical excision with undermining and mobilization of wound edges for closure with interrupted sutures 4
• Island flap technique for larger lesions: oval excision with distal triangular contouring and transposition 4
• Ensure complete cyst wall removal during excision to prevent recurrence 4

Alternative Treatments (Limited Evidence)

• CO2 or erbium-YAG laser therapy may be considered, though evidence is limited to case reports 4
• Intralesional triamcinolone acetonide has been reported but lacks robust evidence 4

Critical Pitfalls to Avoid

• Do NOT attempt needle aspiration as it has only 25% success rate overall and <10% success with MRSA infections 1
• Do NOT pack the wound after incision and drainage, as this increases pain without benefit 1
• Do NOT routinely culture inflamed epidermoid cysts 1, 3
• Recognize that inflammation is typically a sterile foreign body reaction to cyst wall rupture and keratin extrusion into the dermis, not a primary infection 2, 3

Important Clinical Considerations

• Scalp cysts can grow to giant sizes (>5 cm) and may erode through partial or full thickness of the skull 6, 5
• While rare, malignant transformation can occur (squamous cell carcinoma, basal cell carcinoma), making histological examination after excision important 4, 6
• Trichilemmal cysts account for approximately 90% of scalp cysts and require differentiation from proliferating trichilemmal tumors (2% of cases), which are locally aggressive 7