What Are Preauricular Ear Pits?
Preauricular ear pits (also called preauricular sinuses or auricular fistulas) are common congenital abnormalities that appear as small openings in the skin near the front of the external ear, typically located adjacent to the ascending limb of the helix. 1
Clinical Characteristics
Preauricular pits manifest as small dells or openings most frequently positioned:
- At the anterior margin of the ascending limb of the helix (most common location)
- Usually on the right side
- Bilateral in 25-50% of cases (bilateral presentation increases likelihood of genetic inheritance) 1
The visible pit connects to a subcutaneous network of cysts and sinus tracts beneath the skin 2. Most are asymptomatic and benign, requiring no intervention 2.
Embryologic Origin
The most widely accepted theory attributes these malformations to incomplete or incorrect fusion of the six auricular hillocks (mesenchymal proliferations from the first and second branchial arches) during embryonic development 3, 4.
Genetic Pattern
When inherited, preauricular pits follow an incomplete autosomal dominant pattern with:
They can occur either sporadically or as inherited traits.
Critical Clinical Associations
This is where morbidity and mortality considerations become paramount:
Syndromic Associations (3-10% of cases)
Preauricular sinuses are features of other conditions in a small but significant percentage of patients, primarily:
- Branchio-oto-renal (BOR) syndrome (most important association)
- Hearing loss/deafness
- Renal malformations 1, 4
When to Evaluate Further
When other congenital anomalies coexist with preauricular sinuses, auditory testing and renal ultrasound should be considered 1. The ACMG guidelines specifically list preauricular pits among facial/cervical dysmorphology features that warrant evaluation for syndromic hearing loss 5.
Complications and Management
Infection Risk
Sinuses may become infected, most commonly with gram-positive bacteria. When infection occurs:
- Culture exudates
- Administer appropriate antibiotics
- Swelling and discharge can occur at various locations around the ear 1, 6
Surgical Indications
Recurrent infection is a clear indication for complete excision, which provides the only definitive cure 1, 2. However:
- Asymptomatic pits require no intervention 2
- Surgical recurrence rates range from 9-42% 1
- Meticulous excision by an experienced head and neck surgeon minimizes recurrence risk 1
- Complete removal of all fistula tissue and tracts is critical 6
Important Pitfall
Early surgery is recommended when infection occurs because of the tendency toward scarring with repeated infections 4. However, prophylactic excision of asymptomatic pits is not indicated.
Variant Locations
While classically located anterior to the ascending helix, ear pits can occur in ectopic locations including the external auditory canal, lobule, or ascending helix crus itself 6, 7. The clinical significance and association risks appear similar regardless of exact location 7.