Welcome to this Contemporary Pediatrics poll. Take a look at the following case below. After reading through the description, choose a multiple-choice answer and try to guess the correct patient diagnosis.

Then visit our website on September 24, 2025, at 3:00 PM EST or later for the full case presentation, differential diagnosis, and correct patient diagnosis.

This case was presented by Heather Boone, OMS-III; and Neil Cella, MD.

The Case:

A 12-year-old female with no significant past medical history presents to our Emergency Department with 3 days of right-sided neck swelling, which has progressively worsened. The patient notes some pain with chewing on the right side, which has led to decreased intake. The parents report no known fevers but note that other members of the family have recently been sick with a suspected viral illness. The family also reports that this is a recurrent issue that occurs 2 to 3 times a year and endorses that it began after her tonsillectomy procedure. They state that symptoms typically resolve after a course of antibiotics. She has been seen at an ENT clinic for these concerns in the past, with reportedly no solution. She has no other known medical diagnoses or surgeries and is not taking any medications. She lives with her parents and 3 siblings and is in 7th grade.

Her vital signs, including temperature, are within normal limits upon arrival. Physical exam is significant for an indurated, moderately-tender, swelling approximately 2 cm in diameter located anteroinferior to the mastoid process. An oral exam is unremarkable aside from reported dental discomfort elicited by right-sided bite testing. Some residual tonsillar tissue is noted. Upon consulting with the team, labs and imaging are ordered, including CBC, CMP, CRP/ESR, LDH, uric acid serum tests, and diagnostic ultrasound. The lab values demonstrate mild hemoconcentration (possibly due to living at high altitude) and a mildly elevated lymphocyte count. Ultrasound findings include limited images showing bilateral hypoechoic foci in the parotid gland and upper neck regions, and a broad differential is provided. Due to these nonspecific findings, a blood culture is ordered, which produces no growth. 

Below, take your best guess at diagnosing this patient.