Stefano Pacifici, MS4

The Article: Bedside Emergency Ultrasound in a Case of Acute Parotid Duct Sialolithiasis

The Idea: The etiology of unilateral facial swelling in the emergency setting can be challenging to diagnose based on history and physical alone. Etiologies can range from sialolithasis with duct obstruction, bacterial or viral infection, neoplasms, or infection of tissue surrounding the glands. The use of POCUS by trained emergency physicians can provide reliable and timely diagnosis.

Case Report: 37 M w/ 5 days of progressive unilateral facial swelling and pain exacerbated by eating. Vitals were normal, no history of trauma, and physical exam revealed L facial swelling and TTP from parotid gland to body of mandible. POCUS revealed hyperechoic oval structure within parotid gland and dilation of parotid duct. A diagnosis of sialolithiasis with distal obstruction was made.

Discussion: 80-90% of sialolithiasis occurs in the submandibular duct which about 15% occur in parotid gland and duct. Obstruction can lead to infection and abscess formation. This classically presents with unilateral facial swelling with pain worsened by eating. Bedside ultrasound using high-frequency transducer is the initial imaging modality of choice as it has high sensitivity and specificity. Patients should be instructed to turn face away from transducer and both sides should be imaged for comparison. Calculi are usually hyperechoic foci with shadowing. Often dilation of the duct is visualized in symptomatic patients and doppler can show hypervascularity of the gland if inflamed. Treatment for small (<2mm) stones is typically NSAIDs, massage, or local heat. If sialoadenitis is suspected, anti-staph antibiotics should be used. If there is not improvement, urgent referral to appropriate specialist should occur.