Keywords
peritonsillar abscess - blood tests - deep neck abscess
Introduction
Peritonsillar abscess is a common condition in the field of otorhinolaryngology; however,
due care should be taken because patient background and delayed treatment can cause
severe progression, resulting in deep neck abscess with descending mediastinitis.
We examined the background factors of patients with peritonsillar abscess along with
factors that contribute to long-term hospitalization and progression to deep neck
abscess based on blood test results.
Patients and Methods
This study was conducted in accordance with the Declaration of Helsinki. Approval
for this study was obtained from Kitasato University hospital Institutional Review
Board. We analyzed the data of 113 patients with peritonsillar abscesses, including
those in whom the condition progressed to deep neck abscesses, who were hospitalized
at our department during the 3-year period from August 2014 to August 2017. Treatments
included the intravenous administration of antimicrobials following abscess needle
aspiration or drainage by external skin incision in 107 patients, and intravenous
administration of antimicrobials without surgical treatment in 6 patients. In the
present study, flomoxef was used to treat peritonsillar abscess during this period
in 99 patients. In the other eight patients, meropenem single-agent, ampicillin/sulbactam,
or ceftriaxone/clindamycin was administered. The length of hospital stay was a mean
of 10 days and a median of 5 days (2–200 days). A t-test was used to examine factors involved in patients who required hospitalization
for ≥7 days based on age, body mass index (BMI), disease duration until examination,
white cell count, C-reactive protein (CRP), total protein, albumin (Alb) level, blood
glucose, HbA1c, and estimated glomerular filtration rate (eGFR) levels on blood testing
at the time of the initial examination as well as in those who developed neck abscess.
Results
The patients (79 males and 34 females) had a median age of 36 (7–86) years. The age
distribution of the patients is shown in [Fig. 1]. The most common patients were those in their 20s through 40s, and in all age groups,
male patients tended to be more common.
Fig. 1 Number of patients according to age and gender. The results show that most patients
were in their 20s and 40s, and most patients were male.
Furthermore, the disease duration was a mean of 4.5 days and a median of 4 days (1–14
days). Most patients were examined 3 to 4 days after the appearance of symptoms ([Fig. 2]).
Fig. 2 Disease duration and number of patients. The results show that the disease duration
was mostly 3–4 days.
Blood test results at the initial examination revealed that the most common white
cell count was 10,000 to 15,000/μL in 52% patients followed by 15,000 to 20,000/μL
in 31% (median: 14,050/μL; [Fig. 3]).
CRP levels were slightly elevated at 0 to 10 mg/dL in 47% patients followed by 10
to 15 mg/dL in 28% (median: 10.7 mg/dL; [Fig. 4]).
Fig. 3 Distribution of white cell count at the initial examination. The white cell counts
were mostly 10,000–15,000/μL.
Fig. 4 Distribution of CRP levels at the initial examination. The CRP levels were mostly
0–10 mg/dL.
For bacterial culture tests, pus was sampled by needle aspiration or incision and
drainage of the abscess, and submitted for a culture test using an anaerobic specimen
container. Bacteria culture test was performed in 105 patients (92%), of these, 99
and 6 patients showed positive and negative results, respectively. The culture results
were most common in the descending order for Prevotella spp., Micromonas micros, and Fusobacterium spp., with anaerobic bacteria in 49% phlogogenic bacteria ([Table 1]).
Table 1
The culture of peritonsillar abscess at our department
|
Cultured bacteria
|
|
|
Prevotella spp.
|
13%
|
|
Micromonas micros
|
13%
|
|
Fusobacterium spp.
|
12%
|
|
Group A Streptococcus pyogenes
|
12%
|
|
Normal bacterial flora
|
10%
|
|
Gram-negative anaerobic bacillus
|
7%
|
|
Group F Streptococcus
|
5%
|
|
MSSA
|
4%
|
|
Veillonella spp.
|
4%
|
|
Group C Streptococcus
|
4%
|
|
Others
|
16%
|
Abbreviation: MSSA, methicillin-resistant Staphylococcus aureus.
Furthermore, blood test components at the initial examination, such as white cell
count, CRP, total protein, Alb, blood glucose, HbA1c, and eGFR levels, and background
factors, such as age, BMI, and disease duration, were compared according to the length
of hospital stay (comparison between the <7 day hospital stay group [n = 92] and ≥7 day hospital stay group [n = 21]). The results revealed that the higher the age, white cell count, serum CRP
level, and blood glucose level, the longer the hospital stay, whereas the lower the
total serum protein level, Alb level, and eGFR, the longer the hospital stay ([Table 2]). Furthermore, when the length of hospital stay is expressed using a mathematical
formula according to stepwise multiple regression analysis, then the length of hospital
stay (number of days) = 88.482 + 0.135 × (blood glucose level) – 24.097 × (Alb level)
(adjusted for the degrees of freedom R
2 = 0.376, p < 0.001), where the higher the blood glucose level and the lower the serum Alb level
at the initial examination, the longer the hospital stay tends to be. Moreover, the
condition progressed to deep neck abscess in 9 of 113 patients who were all treated
by lateral neck incision. The length of hospital stay in patients with deep neck abscess
was a mean of 45.8 days and a median of 28 days (12–200 days).
Table 2
The value of each factor according to the length of hospital stay
|
<7 days
(n = 92)
|
≥7 days
(n = 21)
|
p-Value
|
|
Age (y)
|
37.5 ± 20.2
|
55.6 ± 17.1
|
<0.005
|
|
BMI (kg/m2)
|
23 ± 4.0
|
24.6 ± 4.4
|
0.239
|
|
WBC (/BC)
|
14,570 ± 3,440
|
15,090 ± 4,740
|
0.568
|
|
CRP (mg/dL)
|
9.8 ± 6.1
|
18.8 ± 8.0
|
<0.005
|
|
Disease duration (d)
|
4.4 ± 2.0
|
5.2 ± 2.9
|
0.217
|
|
Total proteins (mg/dL)
|
7.5 ± 0.7
|
6.9 ± 0.6
|
<0.005
|
|
Albumin (mg/dL)
|
4.1 ± 0.5
|
3.5 ± 0.3
|
0.012
|
|
Glucose level (mg/dL)
|
117 ± 42
|
151 ± 52
|
0.025
|
|
HbA1c (%)
|
5.9 ± 0.2
|
5.9 ± 1.0
|
0.901
|
|
eGFR (mL/min/1.73 m2)
|
90 ± 21
|
68 ± 29
|
<0.005
|
Abbreviations: BMI, body mass index; CRP, C-reactive protein; eGFR, estimated glomerular
filtration rate; WBC, white blood cell.
After examining each blood-test component of the initial examination (white cell count,
CRP level, total protein level, Alb level, blood glucose level, HbA1c, and eGFR),
and background factors (age, BMI, and disease duration) according to the presence
or absence of deep neck abscess, we found that higher serum CRP levels, with lower
serum total protein, Alb, and eGFR levels, contributed to the progression to deep
neck abscess ([Table 3]).
Table 3
The value of each factor according to the presence or absence of progression to cervical
abscess
|
Without progression
(n = 104)
|
With progression
(n = 9)
|
p-Value
|
|
Age (y)
|
38 ± 18
|
68 ± 12
|
< 0.005
|
|
BMI (kg/m2)
|
23.2 ± 4.34
|
24.5 ± 4.54
|
0.318
|
|
WBC (/BC)
|
14,680 ± 4,550
|
18,590 ± 4,100
|
0.209
|
|
CRP (mg/dL)
|
10.9 ± 7.9
|
26.3 ± 6.5
|
< 0.005
|
|
Disease duration (d)
|
4.4 ± 2.0
|
6.1 ± 3.0
|
0.12
|
|
Total protein (mg/dL)
|
7.5 ± 0.66
|
6.4 ± 0.56
|
< 0.005
|
|
Albumin (mg/dL)
|
4.0 ± 0.5
|
3.0 ± 0.3
|
0.009
|
|
Glucose level (mg/dL)
|
122 ± 41
|
145 ± 80
|
0.21
|
|
HbA1c (%)
|
5.9 ± 1.0
|
5.7 ± 0.1
|
0.508
|
|
eGFR (mL/min/1.73 m2)
|
87 ± 22
|
54 ± 32
|
0.013
|
Abbreviations: BMI, body mass index; CRP, C-reactive protein; eGFR, estimated glomerular
filtration rate; WBC, white blood cell.
Discussion
Peritonsillar abscess is frequently encountered during routine medical practice as
abscesses of the head and neck. It is common among individuals in their 20s through
40s. In infants, the onset of peritonsillar abscess is considered rare because the
capsule of palatine tonsil is thick, making it difficult for inflammation to spread
to the surrounding tissue.[1]
[2] Furthermore, peritonsillar abscess onset is common among young men or those in their
prime.[3] In elderly individuals, peritonsillar abscess is rare because of tonsillar atrophy;
however, patients who develop deep neck abscess caused by peritonsillar abscess are
older than the age group of those with peritonsillar abscess.[4] In the present study, we found that individuals with peritonsillar abscess were
most commonly men in their 20s through 40s.
Generally, the disease duration was approximately 4 days, after which the number of
patients successively decreased. We could not find many studies that considered the
disease duration. However, findings of the present study show that a long disease
duration, i.e., delayed examination by a medical institution, caused abscess formation.
Peritonsillar abscess is often caused by multiple infections, whereby the phlogogenic
bacteria include aerobic gram-positive cocci, gram-positive anaerobic cocci, and anaerobic
gram-negative bacillus present in the oral cavity and pharynx.[5] Generally, the pathogenic bacteria include 20 to 40% anaerobic bacteria, 10 to 40%
aerobic bacteria, and 20 to 40% multiple infections. The isolation frequency of anaerobic
bacteria is high (30–60%), and 87% of isolated anaerobic bacteria cause multiple infections.
Anaerobic bacteria typically include those from Fusobacterium and Prevotella genera.[6] Takemoto et al[7] reported that in patients with peritonsillar abscess, the longer the disease duration,
the higher the pH level of the abscess; in those who developed neck abscesses including
peritonsillar abscess, the higher the pH level, the higher the detection rate of anaerobic
bacteria. Furthermore, they reported that this is because aerobic bacteria cause tissue
necrosis during the early stage of illness, and during the late stage of illness,
anaerobic bacteria proliferation is established as a result of reduced oxidation–reduction
potential. Moreover, at our department, the detection rate of anaerobic bacteria was
high (∼50%) due to prompt submission of the aspirated culture for the anaerobic bacteria
culture test. This provided similar results to those previously reported for phlogogenic
bacteria. Furthermore, the frequency of resistant bacteria among the bacteria detected
in peritonsillar abscesses was not very high, and it cannot be said that severe progression
will occur or treatment prolonged only because resistant bacteria were detected from
clinical findings.[6] On the other hand, in Tokyo, Tama city region, 6.4% bacteria detected in the pus
culture of peritonsillar abscesses were resistant to cephalosporin-based antimicrobials,
whereas bacteria detected in a high rate of 45% were resistant to quinolone-based
antimicrobials[8]; therefore, quinolone-based antimicrobials should be cautiously used. The most common
aerobic bacteria were of the Streptococcus genus, among which, Streptococcus anginosu has drawn attention because it contributes to severe progression in deep neck abscesses.
Furthermore, it has been reported that Streptococcus milleri group infections promote anaerobic bacteria proliferation, and multiple infection
with anaerobic bacteria exacerbated inflammation in a synergistic manner, which is
thought to become refractory.[9]
[10] In the present study, anaerobic bacteria accounted for the majority of phlogogenic
bacteria; the use of antimicrobials that act on anaerobic bacteria is considered;
however, taking into account the possibility of the appearance of resistant bacteria,
it is preferable to use broad-spectrum antimicrobials for a short period.
Recent reports on the mean hospital stay for peritonsillar abscess mostly indicate
a mean hospital stay of approximately 7 days. In the present study, we extracted age,
white cell count, serum CRP, serum total protein, serum Alb, blood glucose levels,
and renal function value as factors that prolong the hospital stay. On the other hand,
disease duration, BMI, and HbA1c were not significant factors. That is, severe progression
cannot be predicted according to background factors of patients such as the presence
of diabetes, degree of obesity, or delayed treatment, but rather according to the
severity of inflammation inferred on the basis of test results at the initial examination,
and associated signs of malnutrition and dehydration could serve as factors to predict
the prolongation of hospitalization and progression to severe illness. The results
were the same for the progression to deep neck abscess.
After examining factors that contribute to the prolongation of hospitalization according
to a stepwise multiple regression analysis, blood glucose levels and serum Alb levels
in the results of the tests performed at the initial examination were suggested to
be important factors in predicting the prolongation of hospitalization, severe progression,
and patient progress.
A previous report showed that highly obese patients had longer hospital stays[11]; however, in the present study, BMI was not a factor that prolonged hospitalization.
Therefore, further studies are needed with a larger subject sample in the future.
Conclusions
The severity of inflammation, malnutrition, and dehydration obtained from blood data
at the initial examination serve as more important factors than the patient background,
disease duration for the prediction of hospital stay prolongation, and severe disease
progression. Among data obtained at the initial examination, we believe that blood
glucose levels and Alb levels are useful in predicting the length of hospital stays.
