Peritonsillar Abscess

Axial CT image shows a multilocular low density collection (arrow) beneath the enlarged right tonsil (arrowhead), which is displaced medially.

Facts: Peritonsillar Infection

• Peritonsillar space is a space between anterior and posterior tonsillar pillar, deep to the tonsillar capsule and below the superior pharyngeal constrictor muscle
• Infection of this space usually arises from tonsillitis or pharyngitis, which can lead to peritonsillar cellulitis or abscess

Differentiation between Cellulitis and Abscess

• Differentiation of cellulitis from abscess has a clinical value, since cellulitis is treated medically but abscess usually requires surgical drainage
• Clinical distinction of the two can be difficult; imaging such as contrast-enhanced CT or ultrasound have been utilized for this purpose
• On CT, abscess appears as a cystic/multilocular low density collection with enhancing rim, with or without presence of gas at the center. Cellulitis appears as homogeneous soft tissue swelling with obliteration of fat planes.

References

1. Domino FJ. the 5-minute clinical consult 2007, 2007.

2. Sakaguchi M, Sato S, Asawa S, Taguchi K. Computed tomographic findings in peritonsillar abscess and cellulitis. J Laryngol Otol 1995;109:449-451.