Transoral Ultrasound Versus no Transoral Ultrasound in Diagnostic Workup of Peritonsillar Abscess

Peritonsillar abscess (PTA) is a collection of pus between the palatine tonsil and the constrictor muscle. PTA is detected by recognizing characteristics during clinical examination: redness, pain, malaise, trismus, and unilateral peritonsillar swelling. Clinical assessment, including inspection and palpation, is the traditional diagnostic method for patients suspected of having PTA. If PTA is suspected, aspiration with a large-gauge needle or incision is performed to drain the abscess . It can be challenging to distinguish PTA and peritonsillar cellulitis (PTC) based on clinical examination alone. Due to the increased availability of point-of-care ultrasound, it is a part of the diagnostic workup of PTA. Several studies have shown that transoral US can improve the diagnostic accuracy of patients with a suspected PTA. However, no large multicenter study has evaluated whether one of these methods is superior to the other. It is therefore very clinician-dependent whether the patient will have a transoral US performed or not. The investigators hypothesize that transoral US will increase the diagnostic accuracy of PTA compared to solely clinical examination, which is a visual and palpatory assessment. This will result in fewer unnecessary aspiration attempts and overlooked PTAs. Additionally, the investigators wish to investigate the number of aspirations of transoral US-guided needle aspirations compared to aspirations without ultrasound. Methods This is a cluster randomized study. Patients with suspected PTA will be randomized 1:1 to groups A and B. The cluster randomization will happen weekly using an online randomization tool. Participants are patients refeered to the outpatient clinic on suspicion of a peritonsillar absces. The primary outcome is the diagnostic accuracy The investigators aim to determine whether transoral US is a standard part of the clinical examination by comparing clinical examinations with and without US.

NCT Number	NCT07577232
Lead Sponsor	Rigshospitalet, Denmark
Conditions	Peritonsillar Abscess, Peritonsillar Cellulitis, Tonsillitis
Enrollment	368 participants
Start Date	2025-06-09
Primary Completion	2026-06-01 (estimated)
Study Completion	2026-07-01 (estimated)
Updated on ClinicalTrials.gov	2026-05-11