Peritonsillar Abscess



  • Suppurative complication of tonsillitis where infection spreads outside the tonsillar capsule between the palatine tonsil and pharyngeal muscles
  • Most common deep infection of the head and neck (incidence of 30/100,000 per year)
  • In the U.S., 45,000 cases annually
  • Occurs in all ages, more commonly in young adults (mean age 20–40 yr)
  • Occurs most commonly November–December, April–May (coincides with highest incidence rates of streptococcal pharyngitis)
  • Complications:
    • Airway compromise (uncommon)
    • Sepsis (uncommon)
    • Recurrence (12–15%)
    • Extension to lateral neck or mediastinum
    • Spontaneous perforation and aspiration pneumonitis
    • Jugular vein thrombosis (Lemierre syndrome)
    • Poststreptococcal sequelae (glomerulonephritis, rheumatic fever)
    • Hemorrhage from extension and erosion into carotid sheath
    • Severe dehydration
    • Intracranial extension (meningitis, cavernous sinus thrombosis, cerebral abscess)
    • Dural sinus thrombosis


  • 2 theories explain the development of peritonsillar abscess (PTA):
    • Direct bacterial invasion into deeper tissues in the patient with acute pharyngitis
    • Acute obstruction and bacterial infection of small salivary glands (Weber glands) in the superior tonsil
  • Smoking may be a risk factor
  • Most common pathogens:
    • Group-A Streptococcus
    • Staphylococcal species, including methicillin-resistant Staphylococcus aureus (MRSA)
    • Anaerobes (Prevotella, Peptostreptococcus, Fusobacterium)
    • Polymicrobial

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