Preauricular Pits and Infection

One aspect of caring for children that often causes some uncertainty in providers is encountering a Congenital Anomaly. Some are critical and garner a lot of attention (like Congenital Heart Disease), while others attract our attention only when we are confronted with them (like congenital diaphragmatic hernia, congenital adrenal hyperplasia). Still, there are other interesting anomalies that may not even be the reason the patient is in the ED that day, but deserve our respect as they can become complicated. Thyroglossal Duct Cysts and Sacral Dimples may not be complicated today, but certainly can become the primary issue. Let’s review another congenital anomaly that may not be the primary problem, but does deserve our understanding to help avoid complications – Preauricular Pits:

Preauricular Pits: Basics

  • Preauricular pits are a common congenital anomaly. [Han, 2020]
    • Incidence varies from 0.1% to 10%.
    • Higher incidence rates in patients with Asian and African ancestry.
  • May occur sporadically or with a hereditary pattern. [Han, 2020; Rataiczak, 2017]
    • Believed to be the result of an incomplete embryonic fusion of the 6 Hillocks of His.
    • They are distinct from 1st Branchial Cleft Cysts.
      • These typically extend into the external auditory canal.
      • May present at the angle of the mandible or the submandibular area.
  • May be associated with other congenital abnormalities. [Han, 2020]
    • Branchio-oto-renal and Branchio-oculofacial syndromes may have multiple preauricular pits or branch cleft abnormalities.
    • May be associated with renal anomalies – ask about family history of syndromes, renal impairment, or hearing impairment.
  • Preauricular Pits are: [Han, 2020; Rataiczak, 2017]
    • Pinpoint Depressions located at the anterior margin of the ascending limb of the auricular helix.
    • More often on the right side of the face.
  • Preauricular Pits can extend superior to the auricle or also posterior to the auricle. [Rataiczak, 2017]
    • The pit marks the entrance to an underlying sinus tract.
    • The underlying tracts are complex and multi-branched.
    • These tracts can be very close to the cartilage, making complete removal difficult.
  • Most preauricular pits are asymptomatic. [Isaacson, 2019]
  • They can become infected and have local inflammatory changes. [Isaacson, 2019; Rataiczak, 2017]]
    • The infected pit’s sinus and cyst rupture and spill infected squamous debris into the subcutaneous regions.
    • Intense inflammatory reactions occur.
    • Chronic inflammation can lead to persistent changes to the overlying skin and be cosmetically deforming.
    • Can even create chronic abscess formations.

Preauricular Pits: Infected

Infected Preauricular Pit: Not as easy as you’d think.
  • Preauricular pits do not require any specific therapy if they are not complicated. [Han, 2020]
  • Unfortunately, they are at risk of becoming infected and infected preauricular pits become problematic.
  • Preauricular pits that have signs of infection need to be removed. [Han, 2020, Isaacson, 2019]
    • There is no consensus on the best method to remove the preauricular pit.
    • If a portion of the pit’s tract is left behind, the pit and cyst may recur.
    • Large excisions risk facial nerve injury and may affect cosmetic outcomes.
    • In general though, surgical excision is performed AFTER control of the infection is achieved.
  • There is evidence that infected preauricular pits have a higher recurrence rate if an incision and drainage was performed on them prior to surgical excision. [Rataiczak, 2017]
  • If a preauricular pit does not respond quickly to conservative management (ie, antibiotics and/or fine needle aspiration), then there is evidence that excision of the infected pit and cyst can still be done successfully. [Han, 2020; Rataiczak, 2017]
My Personal Take Away from the Literature (humbly presented)
  • First of all, while an un-infected preauricular pit does not require intervention, they are at risk of becoming infected, so anticipatory guidance will help families know what to look for and the need to seek care early for increased swelling, pain, redness, etc.
  • The infected preauricular pit does need our care now… but…
    • Since there is evidence (although not the most robust) that incision and drainage can increase risk for recurrence, I would prefer NOT to perform I&D of the infected preauricular pit/cyst in the ED. [Isaacson, 2019; Rataiczak, 2017]
    • I would be eager to start antibiotics (infections in the face are never kind)… if infection is kept local without significant cellulitis, then it is likely fine to start oral antibiotic therapy.
    • May consider using a small gauge needle for fine needle aspiration of a prominent cyst to help with pain reduction and send sample for culture.
    • Help establish follow-up with pediatric ENT to have close follow-up and definitive excision once infection is managed (ideally).

Moral of the Morsel

  • It may seem simple, but it is complex. The underlying sinus tracts can be very complex. If they become infected, it will not likely be a simple subcutaneous abscess in need of only I&D.
  • Cold Steel is not always the answer. With the potential for bedside I&D causing increased risk for recurrence after the excision, it is better to treat with antibiotics +/- fine needle aspiration.
  • Contact your friendly ENT physician. If you are uncertain about performing fine needle aspiration vs I&D, ask your ENT. Either way, the patient will need close follow-up for definitive excision.

References

Author

Sean M. Fox
Sean M. Fox
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