Pilonidal Disease and Perianal Hidradenitis

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Pilonidal Disease (PD)

Etiology

• Definition: Acquired disease causing subcutaneous infection of hair shafts in the sacrococcygeal region.
• Incidence: 26 per 100,000 people.
• Pathogenesis:
  • Acquired Theory:
    • Hair shafts penetrate skin, causing a foreign-body reaction.
    • Intergluteal cleft creates vacuum force drawing hair into subcutaneous tissue.
    • Factors: Local irritation, embedding of loose hairs, and vulnerability of skin.
  • Historical Theories:
    • Previously thought to be congenital due to embryonic anomalies.
    • Termed "Jeep disease" in WWII due to high incidence among soldiers.

Presentation

• Demographics:
  • 2.2 times more common in men.
  • Affects individuals aged 15-40 years.
  • Risk Factors: Obesity, heavy hair growth, family history, local trauma, sedentary occupation.
• Symptoms:
  • Acute Form:
    • Painful sacrococcygeal abscess.
    • Fluctuant mass with overlying cellulitis, located just above gluteal cleft.
  • Chronic Form:
    • Draining sinuses with one or multiple midline pits.
    • Presence of hair debris in sinus tracts.

Diagnosis

• Clinical Diagnosis: Based on characteristic appearance.
• Differential Diagnosis:
  • Exclude: Furuncle disease, hidradenitis suppurativa, perianal abscess/fistula, sacral osteomyelitis, syphilis, tuberculosis, actinomycosis.
• Malignant Degeneration:
  • Rare (0.1%), usually squamous cell carcinoma.
  • Occurs in long-standing disease; requires histologic examination.
• Histology:
  • Midline pits lined with squamous epithelium.
  • Cavities lined with granulation tissue.
  • Hair shafts found in 75% of cases.
  • Presence of foreign-body giant cells.
• Microbiology:
  • Typically gram-negative and anaerobic organisms.
  • Shift to gram-positive and aerobic bacteria in recurrent cases.

Treatment

Goals

• Achieve complete wound healing.
• Minimize patient disability.
• Reduce recurrence rates.

Acute Pilonidal Abscess

• Standard Treatment: Simple incision and drainage.
  • Provides prompt symptom relief.
  • Definitive resection is deferred to reduce recurrence.
• Technique:
  • Patient in prone jackknife position.
  • Paramedian longitudinal incision over abscess.
  • Removal of debris and hair.
  • Unroofing and fulguration of sinus tracts may reduce recurrence.
• Postoperative Care:
  • Sitz baths for hygiene.
  • Weekly wound checks to prevent hair accumulation.
  • Laser hair removal as adjunct therapy.

Chronic Pilonidal Disease

• Nonresectional Approach:
  • Hair control by shaving.
  • Good perineal hygiene.
  • Limited lateral incision and drainage.
  • Removal of visible hair from sinuses.

• Midline Follicle Excision and Lateral Drainage (Bascom Procedure):

  • Excision of midline pits.
  • Lateral incision for drainage and debridement.
  • High cure rates (~84%).
  • Can be performed outpatient.

  

• Incision and Curettage with Marsupialization/Saucerization:

  • Derroofing of sinus tracts.
  • Curettage of granulation tissue.
  • Marsupialization: Suturing skin edges to wound base.
  • Saucerization: Beveling skin edges for drainage.
  • Low recurrence rates (1–19%).
  • May involve more postoperative pain.
  • Negative pressure wound therapy can aid healing.

  

• Excision with or without Closure:

  • Wide excision down to sacral fascia.
  • Wound may be left open or closed primarily.
  • Primary Closure:
    • Faster healing time.
    • Earlier return to work.
    • Off-midline closure reduces infection and recurrence.

  • Open Healing:

    • Potentially lower recurrence.
    • Requires longer healing period.

    

Recurrent or Unhealed Pilonidal Disease

• Flap Procedures:
  • Used for extensive or complex disease.
  • Types: Z-plasty, V-Y flap, Limberg flap, Karydakis operation, Cleft Lift Procedure.
  • Aim to flatten natal cleft and shift incision off midline.
• Cleft Lift Procedure (Bascom):
  • Excision of midline nonhealing wound.
  • Creation of a full-thickness skin flap.
  • Lateralization of incision line.
  • Low recurrence rates (<5%).
  • Performed outpatient.

Summary

• PD is a chronic condition causing significant morbidity.
• Surgical approach should be tailored to disease presentation.
• Hair removal is essential for healing and preventing recurrence.
• Aim to avoid chronic nonhealing wounds.

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Perianal Hidradenitis Suppurativa (HS)

Etiology

• Definition: Chronic inflammation of apocrine glands, leading to abscesses and draining sinuses in the perianal region.
• Pathogenesis:
  • Occlusion of apocrine ducts/hair follicles by keratin.
  • Secondary infection with skin flora.
  • Suppuration and rupture into subcutaneous tissue.
• Risk Factors:
  • Strongly associated with obesity and smoking.
  • Hormonal influence (androgen excess).
  • Familial cases suggest an autosomal dominant inheritance pattern.

Presentation

• Demographics:
  • Prevalence: 98 per 100,000 persons.
  • More common in women (twice as likely).
  • Higher incidence in African American and biracial individuals.
  • Onset typically in the third decade of life.
• Symptoms:
  • Painful subcutaneous nodules.
  • Recurrent abscesses and draining sinuses.
  • Chronic disease leads to cicatricial networks and fibrosis.
• Severity Classification (Hurley Stages):
  • Stage I: Single/multiple abscesses without sinus tracts.
  • Stage II: Recurrent abscesses with sinus tract formation.
  • Stage III: Diffuse involvement with interconnected tracts.

Diagnosis

• Clinical Diagnosis: Based on presentation and history.
• Differential Diagnosis:
  • Exclude: Acne conglobata, perifolliculitis capitis, lymphogranuloma venereum, erysipelas, tuberculosis.
  • Perianal Crohn Disease: Must be ruled out; colonoscopy if suspected.
• Malignant Transformation:
  • Rare but possible; usually squamous cell carcinoma.
  • Requires wound surveillance and histologic examination.

Treatment

Goals

• Control symptoms.
• Prevent recurrence.
• Manage chronic disease effectively.

Medical Therapy

• Topical Clindamycin:
  • Effective in reducing symptoms.
• Systemic Tetracycline:
  • Similar efficacy to topical treatments.
• Hormonal Therapy:
  • Leuprolide for hormonal suppression.
• Other Medications:
  • Isotretinoin and Cyclosporine (used cautiously due to side effects).
• Biologic Agents:
  • Adalimumab (Humira) targets TNF-α.
  • Secukinumab (Cosentyx) targets IL-17.

Surgical Therapy

• Incision and Deroofing:
  • For acute abscesses.
  • Deroofing reduces recurrence compared to simple incision.
• Limited Local Excision:
  • Suitable for limited disease.
  • Excision of tracts with primary closure.
  • Low cure rates; high chance of recurrence elsewhere.
• Wide Excision:
  • Recommended for chronic/extensive disease.
  • Excision of apocrine gland–bearing skin to fascia or 0.5 cm margins.
  • Intraoperative marking with dyes ensures complete removal.
  • Colostomy not routinely required.
• Reconstruction Options:
  • Primary Closure:
    • May not reduce recurrence.
  • Split-Thickness Skin Grafting (STSG):
    • Rapid wound coverage.
    • Requires care of graft and donor sites.
    • Delayed grafting improves success.
  • Advancement Flap Coverage:
    • Early wound closure.
    • V-Y advancement flaps commonly used.
    • Higher complication rates (up to 25%).
  • Healing by Secondary Intention:
    • May involve negative pressure wound therapy.
    • Benefits include improved healing and patient comfort.

Summary

• Perianal HS is a chronic inflammatory condition of apocrine glands.
• Management depends on disease severity and extent.
• Wide excision is preferred for chronic/extensive disease to minimize recurrence.
• Reconstruction should be tailored to patient needs and institutional resources.

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Note: Regular follow-up and patient education are essential components of managing both PD and perianal HS to ensure optimal outcomes and prevent recurrence.