Updated: 12/16/2021

Pilonidal Cyst

Review Topic
  • Snapshot
    • A 17-year-old male presents with lower back pain. He reports that the pain worsens when he sits or bends forward. Medical history is significant for metabolic syndrome. He is a high school student who spends hours playing online computer games. On physical exam, there is a tender and fluctuant mass that is erythematous. There is also purulent discharge from a sinus tract.
  • Introduction
    • Clinical definition
      • skin and subcutaneous tissue infection occurring in the sacrococcygeal region leading to an acute or chronic abscess
  • Epidemiology
    • Incidence
      • approximately 70,000 cases per year
    • Demographics
      • 15-30 years of age
    • Location
      • gluteal cleft
    • Risk factors
      • increased hair
      • poor hygiene
      • prolonged sitting
      • skin pits
      • trauma or irritation of the region
      • obesity
      • family history
  • EitIoLOGY
    • Pathophysiology
      • pathoanatomy
        • unclear
        • possibly due to stretching the natal cleft which damages the hair follicles and creates a pore "pit"
          • pore serves as an environment for hair to become embedded
          • hair is drawn deeper into the pore, resulting in a foreign body reaction and creating a subcutaneous cavity
  • Presentation
    • Symptoms
      • asymptomatic
      • intergluteal region pain while the patient is
        • sitting or partaking in activities that stretch the natal cleft (e.g., bending)
      • swelling
      • drainage that can be mucoid, bloody, or purulent
      • fever
      • malaise
    • Physical exam
      • pores found in the midline of the natal cleft
      • painless sinus opening
      • tender mass or sinus with fluid drainage
      • mass may be fluctuant and erythematous
  • Studies
    • Diagnostic criteria
      • clinical diagnosis
  • Differential
    • Perianal abscess
    • Hidradenitis suppurativa
    • Anorectal fistula
    • Folliculitis
    • Perianal furuncle and carbuncle
    • Perianal complications from Crohn's disease
  • Treatment
    • Operative
      • incision and drainage
        • indication
          • considered first-line for acute pilonidal cyst
      • surgical excision of the sinus tract
        • indication
          • chronic or persistent pilonidal cyst
  • Complications
    • Cellulitis
    • Abscess
    • Squamous cell carcinoma
      • this is rare
  • Prognosis
    • Approximately 50% of patients with acute pilonidal cyst may develop a chronic pilonidal cyst
    • Approximately 20% of cases treated with initial surgery have recurrence of the disease
Flashcards (0)
1 of 0
Questions (1)

(M2.DM.17.4799) A 32-year-old man presents to his primary care physician complaining of a “boil” on his back. He first noticed a painful lump in the area one week ago, and he feels that it has increased in size since then. He states that it has become so painful that he has difficulty sitting still or lying flat on his back at night. He has not noticed any discharge from the lump. The patient has a past medical history of obesity and type II diabetes mellitus. He is currently taking metformin. He has a family history of beta-thalassemia in his mother and hypertension in his father. The patient is a computer programmer and in the evenings he plays ultimate frisbee. He smokes half a pack a day. At this office visit, his temperature is 98.2°F (36.8°C), pulse is 75/min, blood pressure is 138/82 mmHg, and respirations are 13/min. Physical exam is notable for the skin finding shown in Figure A. Which of the following is the best next step in management?

QID: 109185

Surgical excision



Cefazolin and metronidazole



Use of hot compresses



Incision and drainage



Ensure dryness and cleanliness in the affected area



M 7 E

Select Answer to see Preferred Response

Private Note