Peritonsillar cellulitis


  • Peritonsillar cellulitis- inflammatory reaction between palatine tonsil and pharyngeal muscle with no discrete collection of pus.
  • Peritonsillar abscess - collection of pus located between palatine tonsil and pharyngeal muscle.

Clinical Features

  • Imaging may be necessary to differentiate peritonsillar abscess (PTA) from peritonsillar cellulitis, epiglottitis, deep space neck infection
  • Intraoral or submandibular ultrasound distinguish PTA from cellulitis and guide needle aspiration
  • Submandibular ultrasound may be superior to intraoral ultrasound when limited by trismus or pain.
  • PTA will have echo-free cavity with irregular border
  • Peritonsillar cellulitis appears as homogenous area with no fluid collection
  • Do not recommend CT to differentiate PTA from cellulitis
    • Recommend CT with IV contrast to identify deep space neck infection
  • Clinical features may not always distinguish PTA from cellulitis
    • 24-hour trial of antimicrobial therapy may be helpful
      • Response is defined by improvement of sore throat, fever, trismus or alleviation of tonsillar inflammation

Differential Diagnosis

Acute Sore Throat

Bacterial infections

Viral infections





  • Antibiotic therapy
    • Oral
      • Amoxicillin-clavulanate (45mg/kg per dose [max 875mg single dose]) x 12 hours in children; 875 mg x 12 hours in adults
      • Clindamycin (10mg/kg [max 600mg single dose]) x8 hours in children; 300-450mg x 6 hours in adults
    • Parenteral
      • Ampicillin-sulbactam (no MRSA coverage) IV (50mg/kg per dose [max 3g single dose]) x 6 hours children; 3g x6 hours adults
      • Clindamycin IV (13mg/kg per dose [max 900mg single dose]) x8 hours children; 600mg x6-8 hours adults
      • If moderate to severe disease (toxic, temp>39C, drooling, respiratory distress) add IV vancomycin or linezolid assed to ampicillin-sulbactam or clindamycin


See Also

External Links


  1. Melio, Frantz, and Laurel Berge. “Upper Respiratory Tract Infection.” In Rosen’s Emergency Medicine., 8th ed. Vol. 1, n.d.