Predicting failure of detection of peritonsillar abscess with ultrasound in pediatric populations

Abstract

Purpose: Some patients require additional imaging following ultrasound (US) to definitively diagnose a peritonsillar abscess (PTA), delaying intervention and disease resolution. We seek to evaluate patient characteristics which may predispose to a secondary imaging requirement to diagnose PTA, in order to better understand ultrasound limitations and predict who will require additional studies.

Materials and methods: Retrospective chart review of patients with an US for suspected PTA between July 2017 and July 2020. Patient age, weight, and clinical characteristics, such as pain, trismus, and reduced neck range of motion (ROM) were collected. The need for additional imaging, subsequent surgical intervention, and hospital length of stay (LOS) were also recorded.

Results: Of 411 qualifying patients, 73 underwent additional imaging. Patients who required additional imaging were younger (9.8 vs 11.3 years, p = 0.026) and more likely to have decreased neck ROM (17.8 vs 5.3 %, p = 0.001). Surgical intervention was performed more commonly (27.4 vs 14.8 %, p = 0.015) and hospital LOS was longer (24.0 vs 5.0 h, p < 0.001) in those with secondary imaging.

Conclusions: Specific patient characteristics, such as younger age and decreased neck range of motion, are associated with a higher need for additional imaging. Additionally, the need for additional imaging is associated with a longer hospital LOS and increased likelihood of surgical intervention. Nearly 18 % of patients who underwent US evaluation of PTA required secondary imaging. Although transcervical US remains an excellent tool for diagnosing PTA, this data supports the utility of secondary imaging in certain instances.

Keywords: Pediatric head and neck infection; Pediatric peritonsillar abscess; Transcervical; Ultrasound.