INTRODUCTION: Peritonsillar infection is a common complication to acute tonsillitis in younger adults. If peritonsillar cellulitis progresses to a peritonsillar abscess (PTA), the primary treatment is surgical drainage. But distinguishing cellulitis from PTA on a standard clinical examination is difficult. This trial aims to explore whether point-of-care transoral ultrasound can improve diagnostic accuracy and guide successful needle aspiration in patients referred with PTA.

METHODS: A randomised, controlled multicentre trial will be conducted at the departments of otorhinolaryngology, head and neck surgery at Rigshospitalet and Odense University Hospital. Patients referred with PTA will be randomised to either standard clinical examination (control) or standard clinical examination with supplemental transoral ultrasound (intervention). The diagnostic accuracy, the total number of performed needle aspirations and the proportion of successful needle aspirations will be compared between the two groups. The difference will be evaluated using binary logistic regression and a generalised estimating equation to adjust for clustering of data within each physician and each hospital. A total of 88 patients are necessary to measure the clinical effect of adding transoral ultrasound.

CONCLUSIONS: This study will explore the clinical benefits of adding transoral ultrasound to the diagnostic work-up of patients with peritonsillar infections.

FUNDING: The Rigshospitalet and Odense University Hospital Foundation.

TRIAL REGISTRATION: Clinicaltrials NCT03824288.