What are the treatment guidelines for pilonidal sinus?

Treatment Guidelines for Pilonidal Sinus

For pilonidal sinus disease, surgical intervention with incision and drainage or excision is the definitive treatment, with marsupialization offering the best balance of low recurrence (6.35%) and acceptable healing time (27 days), while conservative management with hair removal and hygiene alone has limited efficacy and high failure rates. 1, 2

Initial Assessment and Diagnosis

When evaluating pilonidal sinus, search for local predisposing factors including:

• Presence of pilonidal cyst or hidradenitis suppurativa 1
• Foreign material in the sinus tract 1
• Recurrent abscess at previous infection site 1

Recurrent abscesses should be drained and cultured early in the course of infection to guide antibiotic selection if systemic signs develop. 1

Treatment Algorithm Based on Disease Presentation

Acute Pilonidal Abscess

Incision and drainage is the recommended primary treatment for pilonidal abscesses. 1 This applies to all inflamed pilonidal cysts, carbuncles, and large furuncles presenting with acute suppuration.

• Perform incision and drainage as definitive initial management 1
• Consider adjunctive antibiotics only if systemic inflammatory response syndrome (SIRS) is present: temperature >38°C or <36°C, tachycardia >90 bpm, tachypnea >24 breaths/min, or WBC >12,000 or <4,000 cells/µL 1
• For patients with SIRS, prescribe antibiotics active against MRSA and streptococci 1
• Culture the abscess if recurrent disease to guide antibiotic therapy 1

Chronic Pilonidal Sinus Disease

For definitive management of chronic pilonidal sinus, surgical excision with marsupialization is the preferred approach, offering recurrence rates of only 6.35% compared to 57.8% with primary closure techniques. 2

Surgical Options (in order of preference):

1. Marsupialization (first-line for uncomplicated cases):

   • Healing time: 27 days 2
   • Recurrence rate: 6.35% 2
   • Best option in absence of inflammation or recurrence 2

2. Radiofrequency incision and lay-open technique:

   • Can be performed under local anesthesia 3
   • Mean healing time: 67 days 3
   • Same-day discharge with mean 7 days off work 3
   • Low recurrence rates in appropriately selected patients 3

3. Open excision (for large, inflamed, or recurrent disease):

   • Healing time: 46 days 2
   • Recurrence rate: 3.4% 2
   • Preferred for apparently large, inflamed situations 2

4. Primary closure technique (NOT recommended):

   • Highest recurrence rate: 57.8% 2
   • Should be avoided due to poor outcomes 2

Conservative Management (Limited Role)

Conservative therapy has a very limited role and should NOT be considered first-line treatment based on recent high-quality evidence. 4

A 2016 prospective randomized controlled trial demonstrated:

• Conservative treatment cure rate: only 68.3% at 2 years 4
• Surgical treatment cure rate: 100% at 2 years 4
• Relapse rate with conservative treatment: 27.8% vs 2.5% with surgery 4

If conservative management is attempted despite inferior outcomes, it consists of:

• Meticulous hair control by natal cleft shaving 5
• Improved perineal hygiene 5
• Limited lateral incision and drainage for abscess only 5

However, this approach is no longer recommended as primary treatment given the strong evidence favoring surgical intervention. 4

Alternative Conservative Technique (Phenol Injection)

For patients who refuse surgery or have significant comorbidities:

• Local application of 80% phenol into sinus tract after depilation 6
• Mean of 2 injections required 6
• Recurrence rate: 6.3% (95% CI: 1.3-17.2%) 6
• Performed under local anesthesia with low cost and high patient comfort 6

Recurrence Prevention

For patients with recurrent pilonidal sinus:

• Consider 5-day decolonization regimen if S. aureus is cultured: twice-daily intranasal mupirocin, daily chlorhexidine washes, and daily decontamination of towels, sheets, and clothes 1
• Treat with 5-10 day course of antibiotic active against isolated pathogen 1
• Maintain ongoing hair removal and hygiene measures 5

Key Pitfalls to Avoid

• Do not use primary closure technique - it has unacceptably high recurrence rates of 57.8% 2
• Do not rely on conservative management alone - cure rates are only 68% compared to 100% with surgery 4
• Do not delay surgical referral - conservative approaches lead to 27.8% relapse rates requiring eventual surgery anyway 4
• Avoid premature skin edge closure after lay-open procedures, which may require edge trimming 3