II. Epidemiology

  1. Incidence: 70,000 cases in U.S. per year
  2. Infection occurs most often in males, age 16 to 30

III. Predisposing factors

  1. Men
  2. Dark-skin
  3. Hirsutism

IV. Pathophysiology

  1. Pit forms at skin disruption in gluteal fold (may be injured by embedded loose hairs)
  2. Pit plugs with hair and keratin
  3. Pilonidal Cysts forms when drainage of pit is blocked, and abscess forms when infected
  4. Sinus tracts may also develop

V. Symptoms

  1. Pain in gluteal fold
  2. No systemic symptoms

VI. Signs

  1. Midline tender swelling in gluteal fold over Coccyx

VII. Differential Diagnosis

  1. Hidradenitis Suppurativa
  2. Skin Furuncle or abscess
  3. Crohn Disease
  4. Perianal fistula
  5. Perianal Abscess
  6. Malignancy

VIII. Management: Pilonidal Disease without Abscess

  1. Hair removal from the gluteal cleft
    1. Weekly shaving
    2. Consider laser Epilation
    3. Topical phenol helps prevent recurrence
    4. Fibrin glue (with or without surgical excision - see below)

IX. Management: Pilonidal Abscess

  1. Incision and Drainage under Local Anesthesia
    1. Do not make incision in midline (risk of non-healing)
    2. Make small incision lateral to midline
  2. Consider surgical referral for cyst and sinus excision
    1. Many surgical approaches exist (e.g. marsupialization, Healing by Secondary Intention, flap closure)
    2. See recurrence rates below

X. Complications

  1. Pilonidal Abscess (surrounding Cellulitis may be present)
  2. Pilonidal Sinus Drainage
  3. Recurrent infections: 10 to 90%

XI. References

  1. Marx (2002) Rosen's Emergency Medicine, p. 1952
  2. Johnson (2019) Dis Colon Rectum 62(2): 146-57 [PubMed]

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Related Studies

Ontology: Pilonidal Cyst (C0031925)

Definition (MSH) A hair-containing cyst or sinus, occurring chiefly in the coccygeal region.
Concepts Anatomical Abnormality (T190)
MSH D010864
ICD9 685
ICD10 L05 , L05.91, L05.92
SnomedCT 47639008, 200711002, 302223003, 156320006, 267837002, 302224009, 200716007
English Cysts, Pilonidal, Pilonidal Cysts, Pilonidal Sinus, Cyst, Pilonidal, PILONIDAL CYST, Sinus, Pilonidal, Pilonidal sinus/cyst NOS, PILONIDAL SINUS, Pilonidal sinus/cyst, pilonidal cyst, pilonidal cyst (diagnosis), Pilonidal cyst NOS, Pilonidal cyst and sinus, Pilonidal Sinus [Disease/Finding], pilonidal cyst sinus, Cyst;pilonidal, Fistula;pilonidal, pilonidal sinus cyst, pilonidal sinus/cyst (non-specific), pilonidal cysts, sinus pilonidal, coccygeal sinus, cyst pilonidal, pilonidal sinus, pilonidal sinus (diagnosis), Pilonidal sinus/cyst (disorder), Pilonidal sinus (finding), Sinus - pilonidal, Cyst - pilonidal (finding), Pilonidal sinus/cyst NOS (disorder), Coccygeal sinus, Pilonidal sinus, Coccygeal fistula, Piliferous cyst, Pilonidal fistula, Cyst - pilonidal, Cyst - pilonidal (disorder), Pilonidal cyst, coccyx; sinus, cyst; pilonidal, fistula; pilonidal, pilonidal; cyst, pilonidal; fistula, pilonidal; sinus, sinus; coccygeal, sinus; pilonidal, Pilonidal cyst, NOS, Pilonidal Cyst, pilonidal fistula, Sinus;pilondial
French KYSTE PILONIDAL, Kyste pilonidal, Sinus pilonidal
Spanish QUISTE PILONIDAL, Seno pilonidal, quiste/fístula pilonidal, SAI, quiste/fístula pilonidal, SAI (trastorno), fístula coccígea, fístula pilonidal, quiste pilonidal (trastorno), quiste pilonidal, quiste pilífero, seno coccígeo, seno pilonidal, Quiste pilonidal, Quiste Pilonidal, Seno Pilonidal
German PILONIDALZYSTE, Sinus pilonidalis, Pilonidalsinus, Pilonidalzyste
Swedish Pilonidalcysta
Japanese モウソウノウホウ, モウソウドウ, ピロニダールサイヌス, 毛巣洞, 毛巣嚢胞, 毛巣嚢腫, 毛巣瘻
Czech pilonidální sinus, pilonidální cysta, Pilonidální cysta, Pilonidální dutina
Finnish Pilonidaalisinus
Russian EKTODERMAL'NYI KRESTTSOVO-KOPCHIKOVYI SINUS, PILONIDAL'NAIA KISTA, PILONIDAL'NYI SINUS, EPITELIAL'NYI KOPCHIKOVYI KHOD, ПИЛОНИДАЛЬНАЯ КИСТА, ПИЛОНИДАЛЬНЫЙ СИНУС, ЭКТОДЕРМАЛЬНЫЙ КРЕСТЦОВО-КОПЧИКОВЫЙ СИНУС, ЭПИТЕЛИАЛЬНЫЙ КОПЧИКОВЫЙ ХОД
Portuguese QUISTO PILONIDAL, Sinus pilonidal, Quisto pilonidal, Cisto Pilonidal, Seio Pilonidal
Italian Cisti pilonidale, Seno pilonidale
Dutch pilonidale sinus, coccygeus; sinus, cyste; pilonidaal, fistel; pilonidaal, pilonidaal; cyste, pilonidaal; fistel, pilonidalis; sinus, sinus; coccygeus, sinus; pilonidalis, pilonidaliscyste, Pilonidaal cyste, Sinus pilonidalis
Korean 모소낭
Polish Torbiel pilonidalna, Torbiel zawierająca włosy, Torbiel włosowa, Zatoka włosowa
Hungarian pilonidalis cysta, Pilonidalis sinus
Norwegian Sakralcyster, Tvillingcyster, Pilonidal sinus

Ontology: Pilonidal sinus with abscess (C0342988)

Concepts Disease or Syndrome (T047)
ICD10 L05.02
SnomedCT 156321005, 200714005
English pilonidal sinus with abscess (diagnosis), Pilonidal sinus with abscess, Pilonidal sinus with abscess (disorder), pilonidal; sinus, with abscess, sinus; pilonidal, with abscess
Dutch pilonidalis; sinus, met abces, sinus; pilonidalis, met abces
Spanish seno pilonidal con absceso (trastorno), seno pilonidal con absceso

Ontology: Pilonidal disease (C2317114)

Concepts Disease or Syndrome (T047)
SnomedCT 432863009
English Pilonidal disease (disorder), Pilonidal disease, pilonidal disease (diagnosis)
Spanish enfermedad pilonidal, enfermedad pilonidal (trastorno)