Discussion
The purpose of our study was to examine the utility of CT scans for the diagnosis of peritonsillar abscess; more specifically, we hoped to determine if there was there a clinical characteristic of a patient that led to a higher suspicion of pathology that would warrant CT investigation beyond what a history and physical examination could determine.
Our study, to our knowledge, is the first of its kind to compare two populations of patients with peritonsillar abscess whose only difference in management is a CT scan, to better understand if the symptoms and physical exam findings have any influence on the rate of CT scan performance. Taken together, we did not observe any difference in the rates of chief complaint, history of PTA, subjective, or objective data between groups [Tables 1-3].
While there are no consensus statements on the management of peritonsillar abscesses within specialist groups, recent evidence-based reviews call into question the use of a CT scan in uncomplicated peritonsillar abscesses. A 2012 evidence-based review on the management of peritonsillar abscesses by Powell and Wilson argued against the use of CT scans in peritonsillar abscesses (6). One concern raised in arguing for the use of CT scans when a PTA extends beyond the peritonsillar space and into the parapharyngeal space (7). A 2009 study performed by Monobe et al analyzed this concern and found that 90% of superior-type parapharyngeal space abscesses extending from a peritonsillar abscess patients could be drained trans-orally, whereas 58% of inferiorly based peritonsillar abscesses extending to the parapharyngeal space could be drained via a trans-oral approach (8). It may therefore be more suitable in clinically stable patients presenting with a PTA and concern of parapharyngeal extension to undergo an attempt at trans-oral drainage first before pursuing further imaging.
With the advent of bedside ultrasound in the assessment of abscesses in multiple locations of the body, including the head and neck, further analysis of Emergency Medicine abscess management outlined by a 2021 evidence-based review by Menegas et al argues for the use of clinical assessment and possible trans-oral versus trans-cervical ultrasound, and against the use of CT scans in the diagnosis of peritonsillar abscess (9). This, we argue, further calls into question the utility of a CT scan in this specific patient population.
While CT scans do have their utility in diagnosing deep neck space infections, we feel a strong argument has been made against their utility in PTA work-up and management, even in the concern for possible carotid artery injury during drainage (10). A final concern with their use pertains to delays in care, and the unnecessary cost and burden on the healthcare system. Out-of-pocket private CT scans of the neck, according to Canadian data, cost upwards of $500, which does not include the time and remuneration for the CT technologists and interpreting radiologist (11); moreover, this does not include the time and money spent on transporting patients to and from the radiology department, time utilized by nursing and allied health staff, and delays in contacting the otolaryngology service for a consultation. While not the purpose of our study, we do feel that the inappropriate use of CT scans in simple PTA diagnostic work-up may inappropriately delay care of the patient, lead to unnecessary radiation exposure, and increase demand on the health care system. Over-utilization of and increased reliance on diagnostic imaging as a replacement for sound clinical exam and judgement would, by extension, also lead to delays in patient access to necessary emergent imaging