What is the difference in treatment for an infected pilonidal cyst versus a pilonidal abscess?

Treatment Differences Between Infected Pilonidal Cyst and Pilonidal Abscess

The primary difference in treatment is that a pilonidal abscess requires immediate incision and drainage, while an infected pilonidal cyst without abscess formation may be managed with antibiotics initially, though both ultimately require surgical intervention for definitive treatment. 1, 2

Definitions and Diagnosis

• Pilonidal Cyst: A sinus tract containing hair in the sacrococcygeal region that becomes infected but has not yet formed a collection of pus
• Pilonidal Abscess: An infected pilonidal cyst that has progressed to form a collection of pus requiring drainage

Diagnostic Features

• Both conditions present with pain, erythema, and tenderness in the sacrococcygeal region
• Abscess typically presents with more severe pain, fluctuance, and often systemic symptoms
• Ultrasound is the first-line imaging modality to confirm diagnosis and differentiate between the two conditions 2

Treatment Algorithm

For Pilonidal Abscess:

1. Immediate surgical intervention with incision and drainage is the cornerstone of treatment 2, 3

   • Complete drainage is essential to reduce recurrence risk (recurrence rates up to 44% with inadequate drainage) 2
   • Simple incision and drainage alone has >40% recurrence rate 3

2. Surgical options include:

   • Simple incision and drainage (higher recurrence rate of 42%)
   • Unroofing and curettage (lower recurrence rate of 11%) 3

3. Antibiotic therapy should be added when:

   • Systemic signs of infection are present (fever, tachycardia, etc.)
   • Extensive surrounding cellulitis
   • Patient is immunocompromised 1, 2

For Infected Pilonidal Cyst (without abscess):

1. Initial management may include antibiotics if no abscess is present

   • Antibiotics active against both Staphylococcus aureus and streptococci 1
   • Options include:
     • Amoxicillin-clavulanic acid 875/125 mg PO every 12 hours
     • Trimethoprim-sulfamethoxazole for MRSA coverage
     • Doxycycline 100 mg PO q12h for MRSA coverage 2

2. Definitive treatment still requires surgical intervention, but can be scheduled rather than emergent

   • Options include:
     • Excision of the cyst (complete or partial)
     • Marsupialization
     • Primary closure techniques 4

Post-Procedure Management

For Both Conditions:

1. Wound care:

   • Daily sitting in warm water (sitz baths)
   • Regular dressing changes
   • Keep area clean and dry 3

2. Follow-up:

   • Re-evaluation in 48-72 hours to assess healing progress
   • Complete wound healing typically takes 2-8 weeks 3, 4

3. Definitive treatment:

   • Consider complete excision of the pilonidal sinus 4-8 weeks after initial treatment of an abscess to prevent recurrence 3
   • Healing time varies from 2-21 weeks depending on the extent of excision 4

Key Differences in Outcomes

1. Recurrence rates:

   • Simple drainage of abscess: 42% recurrence
   • Unroofing and curettage: 11% recurrence 3
   • Primary closure techniques: 13-30% recurrence depending on location 5

2. Healing time:

   • Simple procedures: 2-5 weeks
   • Extensive excisions: up to 21 weeks 4

Important Considerations

• A recurrent abscess at a site of previous infection should prompt a search for local causes such as a pilonidal cyst 1
• Pilonidal disease can occasionally be associated with more serious complications like epidural abscess, particularly in patients with diabetes or immunocompromise 6
• While pilonidal disease typically occurs in the sacrococcygeal region, it can rarely occur in other locations including the scalp 7

Remember that while immediate management differs between an infected cyst and abscess, both conditions ultimately benefit from definitive surgical treatment to prevent recurrence.