Peritonsillar Abscess

Description

Infectious complication of tonsillitis or pharyngitis resulting in an accumulation of purulence in the tonsillar fossa; also referred to as “quinsy”

Epidemiology

• Most common deep space infection of head and neck
• Seen most commonly in adolescents but occasionally in younger children

Risk Factors

• Tonsillitis
• Pharyngitis

General Prevention

Abscess formation can often be prevented if appropriate antimicrobial therapy is initiated while the infection is still at the cellulitis stage.

Pathophysiology

• Infectious tonsillopharyngitis progresses from cellulitis to abscess.
• The infection starts in the intratonsillar fossa, which is situated between the upper pole and the body of the tonsil and eventually extends around the tonsil.
• The abscess is a suppuration outside the tonsillar capsule, in proximity to the upper pole of the tonsil, involving the soft palate.
• Purulence usually collects within one tonsillar fossa but it may be bilateral.
• The pterygoid musculature may become irritated by pus and inflammation, which leads to the clinical finding of trismus.
• Tonsillar and peritonsillar edema may lead to compromise of the upper airway.

Etiology

• Most abscesses are polymicrobial.
• Group A β-hemolytic streptococci (GABHS) is the most common bacterium isolated.
• α-Hemolytic streptococci is the second most common bacterium reported in most studies.
• Staphylococcus aureus
• Anaerobic bacteria play an important role:
  • Prevotella
  • Porphyromonas
  • Fusobacterium
  • Peptostreptococcus
• Possible synergy between anaerobes and GABHS
• Gram-negatives such as Haemophilus influenzae and, more rarely, Pseudomonas species may be isolated.

Commonly Associated Conditions

• Tonsillitis or pharyngitis usually precedes its development.
• Peritonsillar cellulitis is often associated with infectious mononucleosis.