Transoral Ultrasound Diagnosed Bilateral Peritonsillar Abscess in Patient Admitted With Tonsillitis

ABSTRACT

Transoral ultrasound is a valuable tool for PTA diagnostics, especially when the diagnosis is uncertain due to ambiguous findings.

1. Introduction

Peritonsillar abscess (PTA) is the most common deep infection in the head and neck area, with an annual incidence range of 10–40 per 100,000. It can be challenging to distinguish PTA, peritonsillar cellulitis, and severe tonsillitis, as their symptoms and objective findings overlap. These include trismus, a muffled voice, difficulties swallowing, redness, and throat pain with unilateral dominance, protrusion of the affected side, and a bulging, tense sensation upon palpation. In acute tonsillitis, the symptoms and objective findings are usually bilateral. The one‐sided protrusion and bulging tense sensation upon palpation make a PTA more likely [1]. Treatments of peritonsillar cellulitis and acute tonsillitis are systemic antibiotics, but PTA treatment also includes aspiration, incision, or quinsy tonsillectomy [2].

Ultrasound is a portable imaging modality that can be used for point‐of‐care diagnostics of PTA. Smaller hockey‐stick transducers have made it possible to perform transoral ultrasound, allowing the oropharynx to be scanned directly through the mouth (Figure 1) [3]. Doppler flow can also be used to confirm the presence of an abscess, as an abscess appears as an anechoic or hypoechoic area without Doppler flow. When a tonsil is inflamed, as in acute tonsillitis, ultrasound will often reveal an enlarged tonsil with increased Doppler flow without any larger anechoic areas (Figure 2) [1, 3].

FIGURE 1.

(A–C) Transoral ultrasound images of a normal healthy palatine tonsil, with and without Doppler flow. (D, E) Cervical ultrasound images of a normal healthy palatine tonsil. The palatine tonsil (PT), the constrictor muscle (dashed yellow line), the medial pterygoid muscle (MPM), a peritonsillar abscess (PTA), the Internal carotid artery (ICA), the external carotid artery (ECA), and the styloglossus muscle (SGM), stylopharyngeus muscle (SPM), deep lobe of the parotid (PG), submandibular gland (SMG), mylohyoid muscle (MH), digastric muscle venter posterior (DM), mandible (M causing acoustic echo shadowing).

FIGURE 2.

Transoral ultrasound images of the palatine tonsils (PT) with and without Doppler flow. (A, B) An inflamed tonsil, a patient with acute tonsillitis. (C, D) A superficially inflamed tonsil with an anechoic area (without Doppler flow) situated in relation to the palatine tonsil and superficial to the constrictor muscle, indicating a peritonsillar abscess (PTA). The medial pterygoid muscle (MPM) is situated in the anterior part of the image. The medial pterygoid muscle (MPM) and constrictor muscle (yellow dashed line).

2. Case History

A 43‐year‐old woman was referred by her general practitioner to the ear, neck, and throat (ENT) outpatient clinic with throat pain and trismus, without improvement after 2 days of penicillin treatment. The patient had three episodes of acute residual tonsillitis in the month preceding presentation, with no prior history of peritonsillar abscess or recurrent tonsillitis.

The objective findings included trismus, bilateral symmetric red and swollen tonsils with bilateral peritonsillar edema, uvula in the midline, and bilateral tonsillar exudates (Figure 3). The flexible video laryngoscopy revealed free airways without pharyngeal wall edema. Blood test revealed CRP 148 mg/L.

FIGURE 3.

Inspection of the oropharynx showing the uvula in the midline and the bilateral tonsil hypertrophy with exudates. This image was captured when the patient was under general anesthesia.

3. Differential Diagnosis

With the above findings, the head and neck physician had the following differential diagnosis:

• –Acute bacterial tonsillitis
• –Peritonsillar cellulitis
• –Peritonsillar abscess

4. Investigations

Due to tonsillar symmetry, the patient was diagnosed with severe acute tonsillitis, and the patient was hospitalized for intravenous antibiotics.

The following day, the patients' symptoms and objective findings had not improved. Blood tests revealed an improvement in CRP 111 mg/L.

A transoral ultrasound scan of the palatine tonsils was performed bedside with the patient sitting upright and after the application of a local anesthetic spray (xylocaine, 10 mg/dose). An LA3‐22AI hockey stick transducer and a Samsung RS85 ultrasound machine were used. The tonsils were ultrasound scanned and, surprisingly, revealed bilateral superficially inflamed tonsils with an underlying anechoic area without Doppler flow (Figure 4). Bilateral PTA was diagnosed with transoral ultrasound.

FIGURE 4.

Transoral ultrasound images of the patients' palatine tonsils (PT) with and without Doppler flow. (A, B) The left palatine tonsil with a peritonsillar abscess (PTA). (C, D) The right palatine tonsil with a peritonsillar abscess. The medial pterygoid muscle (MPM).

A computed tomography (CT) scan was performed to ensure there was no parapharyngeal involvement before the patient was planned for surgery (Figure 5). The CT scan shows tonsillar enlargement and bilateral accumulations with rim enhancement.

FIGURE 5.

CT scan of the patient, verifying the bilateral PTA.

5. Treatment

As the patient had significant bilateral edema, a quinsy tonsillectomy was performed, and pus was retrieved from the left and right peritonsillar regions. The pus was sent for examination and revealed normal oropharyngeal bacterial flora.

6. Outcome and Follow‐Up

The patient was discharged the following day with prescriptions for oral penicillin and analgesics, without any follow‐up consultations. The histology revealed normal tonsils without pathology.

7. Discussion

This case demonstrates the utility of transoral ultrasound in patients referred with a severe tonsillar infection. Bilateral PTA is a rare condition. When ultrasound is used routinely, cases like this will not be missed initially, and the diagnosis will be established promptly, avoiding the risk of only unilateral treatment.

Unilateral PTA is frequently seen in head and neck departments, but bilateral PTA is rare and can obscure the typical clinical findings of a PTA. Trismus, throat pain, and swallowing difficulties will be present, but the unilateral dominance, uvula deviation, and protrusion of one affected side may be absent, and if physicians are unaware that bilateral PTA can occur, the condition may be missed. The overall incidence of bilateral PTA is uncertain, but the average incidence is 4.9% in reports of patients who underwent a quinsy tonsillectomy [4]. Transoral ultrasound should be a part of PTA diagnostics and shows a greater diagnostic accuracy than clinical evaluation alone [2]. Transoral ultrasound can be performed bedside and quickly by physicians. This requires an ultrasound machine with a hockey‐stick transducer and physician expertise in transoral ultrasound.

Transoral ultrasound has limitations. It is associated with substantial equipment costs and requires dedicated training to achieve operator proficiency. Additionally, its use is time‐consuming in routine clinical practice. But we believe the benefits surpass the limitations. We recommend transoral ultrasound, in combination with inspection, palpation, and fiberoptic laryngoscopy, to be the primary diagnostic, with CT added in complicated cases.

In this case, the diagnosis of bilateral PTA was established using transoral ultrasound. A CT scan was ordered to evaluate the possible spread of the disease, as this was a complicated case and was difficult to assess fully with transoral ultrasound. Parapharyngeal abscess can be diagnosed and even drained with transoral ultrasound [5]. The CT scan revealed fluid accumulations in enlarged bilateral palatine tonsils.

8. Conclusion

In this case report, bilateral PTA was diagnosed using bedside transoral ultrasound, demonstrating the utility of this modality as an excellent add‐on to the clinical evaluation of patients with severe tonsillar infections. Transoral ultrasound is especially valuable when the diagnosis is uncertain due to ambiguous findings.

Author Contributions

Amalie Hartvig Pall Posselt: conceptualization, project administration, writing – original draft. Mikkel Hjordt Holm Larsen: investigation, writing – review and editing. Tobias Todsen: conceptualization, formal analysis, investigation, resources, writing – review and editing.

Funding

The authors have nothing to report.

Consent

Written informed consent was obtained from the patient in accordance with journal guidelines.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.