Preauricular Ultrasound for Children: Indications and Recommendations
Preauricular ultrasound is not routinely indicated for isolated preauricular sinuses in children without associated symptoms or risk factors, but should be performed when there are additional congenital anomalies, family history of hearing loss, or signs of infection.
Clinical Assessment of Preauricular Sinuses
Preauricular sinuses (ear pits) are common congenital abnormalities that appear as small openings adjacent to the external ear near the anterior margin of the ascending limb of the helix 1. These sinuses can be:
- Unilateral or bilateral (bilateral in 25-50% of cases)
- Inherited (autosomal dominant with reduced penetrance) or sporadic
- Associated with other conditions or syndromes in 3-10% of cases
Imaging Recommendations
When Preauricular Ultrasound IS Indicated:
Presence of additional congenital anomalies
- When preauricular sinuses are accompanied by other malformations or dysmorphic features 2
- Part of suspected syndromes (e.g., branchio-oto-renal syndrome, CHARGE association, Townes-Brocks syndrome)
Family history concerns
- Family history of deafness
- Family history of auricular and/or renal malformations 2
Infection or complications
- Recurrent or persistent infection
- Abscess formation
- Pre-operative assessment to determine the extent and course of the sinus tract 3
When Preauricular Ultrasound is NOT Indicated:
- Isolated preauricular sinuses without other anomalies or symptoms
- Asymptomatic preauricular sinuses without family history of associated conditions
Ultrasound Benefits and Findings
Ultrasound evaluation of preauricular sinuses can:
- Detect the sinus tract (width up to 3mm)
- Identify branching patterns (present in ~27% of cases)
- Detect cystic components (present in ~60% of cases)
- Demonstrate relationship to surrounding structures including the superficial temporal artery 3
- Help in pre-operative assessment for surgical planning
Additional Considerations
Renal Ultrasound Evaluation
The American College of Radiology guidelines do not specifically address preauricular sinuses, but evidence suggests:
- Renal ultrasound should be considered when preauricular sinuses are accompanied by other malformations or dysmorphic features 2
- Isolated preauricular pits without other anomalies or family history do not warrant renal ultrasonography 2
Other Imaging Modalities
For children with suspected complications or when ultrasound is inconclusive:
- MRI provides superior visualization without radiation exposure 4
- CT should generally be avoided in children due to radiation concerns unless absolutely necessary 4
Conclusion
Preauricular ultrasound is a valuable, non-invasive imaging modality that can help evaluate the anatomy of preauricular sinuses when clinically indicated. However, for isolated, asymptomatic preauricular sinuses without other risk factors, routine ultrasound is not necessary. The decision to perform imaging should be based on the presence of associated anomalies, family history, or clinical symptoms.