86 / 232
either case. Interestingly, one of these patients had a CT
scan from an outside facility suggestive of PTA. The
remaining 24 patients were exclusively managed medi-
cally without any treatment failures. After a negative
needle aspiration on initial visit 2 days prior, one patient
returned to the emergency room. This patient was not
determined to have a PTA at the time of representation
and was again managed medically without failure.
Another patient was readmitted following operative inci-
sion and drainage of a clinical PTA due to reaccumula-
tion of infection.
We compared the ages of patients undergoing drain-
age and those not undergoing procedures. After perform-
ing a Mann-Whitney test on these data, we discovered
the
P
value comparing the ages was not statistically sig-
nificant. The box plot in Figure 1 represents these data.
Furthermore, we elected to perform a multivariate anal-
ysis using age, sex, otolaryngologist clinical diagnosis,
and US findings as independent variables to see if any
correlated statistically with the presence or absence of
purulence. These data can be viewed in Table V. US
finding was the only independent variable found to be
correlative with the presence or absence of PTA (
P
<
.05).
The sensitivity and specificity (with 95% confidence
intervals) of transcervical ultrasonography in the diag-
nosis of pediatric PTA are 100% (86.8%-100%) and 76.5%
(58.9%-89.2%), respectively. The positive and negative
predictive values (with 95% confidence intervals) are
52.9% (27.9%-77.1%) and 100% (66.4%-100%), respec-
tively. When a Fisher exact test was performed, the
P
value was statistically significant (
P
<
.01), indicating
an important correlation between a negative US and
patients who were able to be managed medically. Exam-
ples of US images obtained in these patients are present
in Figures 2–4.
DISCUSSION
Peritonsillar abscesses are common in the pediatric
population; however, diagnosis in this cohort is challeng-
ing due to limitations imposed by smaller oropharyngeal
anatomy and the potential for uncooperative patients.
As a result of these clinical hurdles, CT is frequently uti-
lized as a diagnostic tool. One study of pediatric emer-
gency room visits reported that CT was ordered in 65%
of patients in whom a PTA was suspected.
15
Other
groups have reported algorithms that include exams of
the oropharynx under anesthesia or trials of intravenous
antibiotics followed by operative intervention.
16,17
This
study aimed to investigate the role of transcervical US
in diagnosing pediatric PTA.
TABLE IV.
Radiographic Diagnoses of Patients Without Evidence of
Peritonsillar Abscesses.
Diagnosis
No.
Unilateral tonsillitis
11
Bilateral tonsillitis
9
Normal tonsils
2
Parapharyngeal phlegmon
1
Reactive lymphadenopathy
1
Lymphadenitis
2
Fig. 1. Box plot comparing the age of patients undergoing drain-
age procedures and those not undergoing drainage procedures.
There was no statistical difference in age of patients in the two
groups.
Fig. 2. Example of a normal transcervical ultrasound of the tonsil
and peritonsillar region. The tonsil has a striated appearance and
is outlined by the black arrow heads. SMG
5
submandibular
gland; T
5
tongue.
TABLE V.
Multivariate Analysis Assessing Correlation Between Age, Sex,
Otolaryngologist Clinical Diagnosis and US Finding With
Presence/Absence of Peritonsillar Abscess.
Coefficients
Standard
Error
t
Statistic
P
Value
Lower
95%
Upper
95%
Age
0.009 0.009 0.884 .382
2
0.011 0.028
Sex
2
0.030 0.101
2
0.300 .765
2
0.235 0.174
US finding 0.399 0.151 2.637 .012 0.092 0.705
ENT dx
0.229 0.144 1.589 .120
2
0.062 0.520
x
5
diagnosis; ENT
5
ear, nose, and throat; US
5
ultrasound.
Laryngoscope 125: December 2015
Fordham et al.: Transcervical US in Pediatric PTA
64