Ultrasound of Parotitis

In this radiology lecture, we review the ultrasound appearance of parotitis in the pediatric population!

Key teaching points include:

Parotitis = Inflammation of the parotid glands
Acute parotitis is usually infectious, most commonly viral
Mumps is most common viral cause in children, often bilateral
Bacterial parotitis can cause suppurative parotitis seen in premature infants and immunosuppressed children
Acute parotitis on US: Enlarged, heterogeneous, hyperemic gland(s) +/- lymphadenopathy
Since can be bilateral, comparison scanning essential
Bacterial parotitis may be complicated by abscess
“Pomegranate sign” may be seen in setting of acute parotitis: Uniform anechoic foci scattered throughout the gland
Juvenile recurrent parotitis (JRP) = Recurrent inflammatory parotitis in children of unknown etiology
JRP is rare, but second most common cause of parotitis in childhood after mumps
JRP often begins between age 3-6, typically resolves spontaneously after puberty
Usually idiopathic, JRP can be presenting symptom of Sjogren’s syndrome, lymphoma, and underlying immunodeficiency
JRP on US: May be unilateral or bilateral, multiple hypoechoic foci of salivary secretions scattered throughout the gland +/- central calcifications, color Doppler can be normal
Additional causes of parotitis: Sialolithiasis/obstruction, autoimmune (Sjogren syndrome, chronic sclerosing sialadenitis), infectious (HIV, TB), and sarcoidosis (rare in children).