Preauricular Abscess

Basics

Description

  • Acute abscess of a preexisting preauricular sinus
  • Preauricular sinus
    • First described by Van Heusinger in 1864
    • One of the most common congenital abnormalities of the head and neck region
    • Sporadic and inherited occurrence
  • Synonym(s): infected preauricular sinus; infected ear pit; infected preauricular pit

Epidemiology

  • Males and females equally affected
  • Preauricular sinus forms during antenatal period and present at birth but can become apparent at an older age.

Incidence

  • No defined incidence of preauricular abscess
  • Preauricular sinus incidence in the United States is 0.1–0.9%, 0.9% in England, 1.6–2.5% in Taiwan, and 4–10% in some areas of Africa.

Prevalence
No defined prevalence of preauricular abscess

Etiology and Pathophysiology

  • Etiology
    • Most commonly: Staphylococcus spp.
    • Less commonly: Streptococcus spp.
  • Pathophysiology
    • Three theories for preauricular sinus formation: defective fusion of the six auricular hillocks resulting in preauricular sinus; remnants of incomplete closure of the dorsal part of the first pharyngeal groove; and isolated ectodermal folding during auricular development
    • Abscesses are caused by obstruction of these preauricular sinus openings leading to fluid collection within sinus.

Genetics

  • Autosomal dominant pattern with incomplete penetrance and variable expression
  • Rarely associated with branchiootorenal (BOR) syndrome (autosomal dominant disorder)

Risk Factors

  • Poor hygiene
  • Preexisting preauricular sinus
  • Epidermal cysts
  • Pseudocysts of the auricle
  • Calculi

Commonly Associated Conditions

Preauricular sinus is rarely associated with hemifacial microsomia and microtia.

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