What is a preauricular pit?

What is a Preauricular Pit?

A preauricular pit (also called a preauricular sinus) is a common congenital malformation that appears as a small opening or dell in the skin adjacent to the external ear, typically located near the anterior margin of the ascending limb of the helix. 1

Anatomical Features

• The pit manifests as a small skin opening that communicates with a subcutaneous network of cysts and branching tracts beneath the surface 2
• Most commonly appears on the right side of the ear 1
• The opening is typically positioned anterior to the imaginary line connecting the tragus with the posterior margin of the ascending limb of the helix 3
• Bilateral presentation occurs in 25-50% of cases, which increases the likelihood of inherited forms 1

Genetic Pattern

• Can be either inherited or sporadic in origin 1
• When inherited, demonstrates an incomplete autosomal dominant pattern with reduced penetrance and variable expression 1
• Bilateral cases are more likely to represent inherited forms 1

Associated Conditions

• In 3-10% of cases, preauricular pits are features of other syndromes, primarily branchio-oto-renal (BOR) syndrome and conditions associated with deafness 1
• When other congenital anomalies coexist with preauricular sinuses, auditory testing and renal ultrasound should be considered 1, 4
• May be associated with facial/cervical dysmorphology including branchial cysts, cleft palate, and dental anomalies 5
• Can occur alongside microtia/anotia and preauricular tags 5

Clinical Significance

• The vast majority are benign and asymptomatic, requiring no intervention 2
• When asymptomatic and no associated abnormalities are identified, consensus opinion indicates no further action is needed 4
• May become infected, most commonly with gram-positive bacteria, requiring culture and appropriate antibiotics 1
• Recurrent or persistent infection is a clear indication for complete surgical excision, which provides the only definitive cure 1, 4, 2

Important Clinical Pitfall

• A variant type exists where the sinus tract extends posteriorly, presenting as postauricular swelling rather than the typical preauricular location 3
• These variant types have pits positioned posterior to the imaginary tragal extended line and require dual surgical approach (preauricular and retroauricular incisions) for complete excision 3
• Failure to recognize the full extent of the sinus tract, particularly in variant presentations, leads to inadequate treatment and unnecessary repeat procedures 6