Intraoral and transcutaneous cervical ultrasound in the differential diagnosis of peritonsillar cellulitis and abscesses

AIMS: The objective of the present study was to determine the specificity, sensitivity and accuracy of intraoral and transcutaneous ultrasound (US) in the diagnosis of peritonsillar cellulitis and abscess. STUDY DESIGN: Clinical-Prospective. MATERIALS AND METODS: Thirty nine patients were seen at the otorhinolaryngology emergency department of the University Hospital, of the School of Medicine, University of São Paulo, with a clinical diagnosis of peritonsillar cellulitis or abscess. After initial evaluation, all patients were submitted to intraoral and transcutaneous US. RESULTS: Intraoral US was performed on 35 cases and its sensitivity was of 95.2%, the specificity was of 78.5% and the accuracy was of 86.9%. Transcutaneous US was feasible in all 39 patients and diagnosed peritonsillar abscess in 53.8%. There were 5 false-negatives and 1 false-positive result, sensitivity was 80%, specificity was 92.8% and accuracy was 84.5%. CONCLUSIONS: Intraoral US was quite sensitive in the diagnosis of peritonsillar abscesses when performed by an experienced radiologist. Specificity was higher for transcutaneous US compared to intraoral US. However, when transcutaneous US was performed in patients with trismus, it was able to diagnose all peritonsillar abscesses, since they were large collections which are common in patients with trismus. These exams showed similar accuracy.