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