Pilonidal cyst

Background

• Sinus is formed by penetration of skin by ingrowing hair
  • Leads to foreign body granuloma reaction, sinus perpetuated by repeated bouts of infection
• Carcinoma is rare complication of chronic, recurring pilonidal sinus disease

Clinical Features

• May present as a painless cyst, acute abscess, or recurring cysts with draining sinuses
• Occurs in midline in the upper part of the natal cleft
  • Does not communicate with the anorectum
  • Because of proximity to anus can be confused for a perianal abscess

Differential Diagnosis

Anorectal Disorders

• Anal fissure
• Anal fistula
• Anal malignancy
• Anal tags
• Anorectal abscess
• Colorectal malignancy
• Condyloma acuminata
• Constipation
• Crohn's disease
• Cryptitis
• GC/Chlamydia
• Hemorrhoids
  • Internal hemorrhoid
  • External hemorrhoid
• Pedunculated polyp
• Pilonidal cyst
• Proctitis
• Pruritus ani
• Rectal foreign body
• Rectal prolapse
• Syphilitic fissure

Evaluation

• Clinical

Management

• I&D - longitudinal incision lateral to sacral midline
• Antibiotics only needed if cellulitis is present
• Refer to surgeon for recurrent disease
  • 40% recurrence rate
  • Refer for follicle removal after acute inflammation subsides (~1 wk)

See Also

• Anorectal Disorders