The use of ultrasound evaluation in the diagnosis of peritonsillar abscess.

Peritonsillar Abscess (PTA) and Peritonsillar Cellulitis (PTC) are very similar clinical conditions. The differential diagnosis between them is made by needle aspiration, a very painful and invasive method. This study was performed at the Department of Otolaryngology at the Clinical Hospital of São Paulo University Medical School. It's aim was to evaluate the use of ultrasound as a noninvasive and inexpensive method of diagnosis, differentiating abscess from cellulitis. Twenty-one consecutive patients with a clinical diagnosis of peritonsillar infection were evaluated in the emergency service with a probable diagnosis of PTA. These patients were evaluated with intraoral and percutaneous ultrasound. Needle aspiration was used to compare and confirm the diagnosis. The sensitivity was 92.3% and specificity was 62.3%. The authors conclude that ultrasound is a good method to evaluate the differences between PTA and PTC.