Peritonsillar Abscess

Aka: Peritonsillar Abscess, Peritonsillitis, Peritonsillar Cellulitis, Quinsy sore throat

1. Pathophysiology
   1. Sequelae of acute Tonsillitis or tonsillopharyngitis
   2. Progression from exudative Tonsillitis to Peritonsillar Cellulitis to Peritonsillar Abscess
      1. Abscess develops within the Weber's Glands (mucous Salivary Glands within Soft Palate)
2. Risk Factors
   1. Exudative Tonsillitis
   2. Periodontal Disease
   3. Tobacco Abuse
3. Etiology
   1. Group A Streptococcal Pharyngitis complication
      1. Streptococcus Pyogenes (most common aerobic organism)
   2. Mixed oropharyngeal flora
      1. Staphylococcus aureus
      2. HaemophilusInfluenzae
      3. Neisseria
      4. Anaerobic Bacteria
         1. Fusobacterium
         2. Peptostreptococcus
         3. Prevotella
         4. Bacteroides
4. Symptoms
   1. Fever over 39.4 suggests more serious infection
      1. Parapharyngeal space infection
      2. Sepsis
   2. Severe, unilateral throat pain
   3. Dysphagia
   4. Trismus
   5. Muffled ("hot potato") voice
   6. Drooling
5. Signs
   1. Ill appearance
   2. Uvula deviates to the opposite side
   3. Localized swelling of Soft Palate over affected tonsil
   4. Swollen tonsil (usually superior pole)
      1. Indurated, fluctuant mass
      2. Exudate may be present
      3. Erythematous peritonsillar area
      4. Usually unilateral
6. Labs
   1. Complete Blood Count (CBC)
   2. Throat Culture
   3. Streptococcal Rapid Antigen Test
   4. Monospot
7. Imaging
   1. Indications
      1. Confirm Peritonsillar Abscess where the diagnosis is uncertain (Ultrasound)
      2. Evaluate contiguous soft tissues and vessels (CT or MRI)
   2. Neck ultrasound (preferred imaging modality for diagnosis)
      1. Transducer intraoral or over Submandibular Gland
      2. Abscess is echo-free with irregular border
   3. CT Neck with contrast
      1. Abscess shows low attenuation
      2. Shows contiguous spread of infection to deep neck tissue
   4. MRI neck
      1. Evaluate for deep neck infections
      2. Evaluate jugular and carotid vessels
8. Differential Diagnosis
   1. Peritonsillar Cellulitis (no pus in capsule)
   2. Tonsillar abscess
   3. Mononucleosis
   4. Cervical adenitis
   5. Dental infection (e.g abscessed tooth)
   6. Sialolithiasis or Sialadenitis
   7. Mastoiditis
   8. Internal cartoid artery aneurysm
   9. Malignancy (e.g. Lymphoma)
9. Management
   1. Appropriate Healthcare
      1. Children: Hospitalize for IV antibiotics
      2. Adults: Outpatient unless dehydrated or toxic
   2. Antibiotics for 10-14 days
      1. Base antibiotic choice on needle aspiration sample
      2. Parenteral
         1. Combination
            1. Penicillin G 10 MU IV every 6 hours and
            2. Metronidazole 1.0 g load, and then 500 mg IV every 6 hours
         2. Cefoxitin 2 g IV q8h
         3. Clindamycin 900 mg IV every 8 hours
         4. Timentin
         5. Piperacillin
         6. Ampicillin with Sulbactam (Unasyn) 3 grams every 6 hours
      3. Oral agents
         1. Clindamycin 500 mg PO bid
         2. Second and Third Generation Cephalosporins
         3. Augmentin 875 mg orally twice daily
         4. Combination
            1. Penicillin VK 500 mg orally every 6 hours and
            2. Metronidazole 500 mg orally every 6 hours
   3. Experimental: Corticosteroids as adjunct to antibiotics
      1. Do not use routinely until larger studies are completed
      2. Patients improved faster when adjunctive steroids were used
         1. Protocol used Depo Medrol 2-3 mg/kg up to 250 mg IV for 1 dose
      3. Reference
         1. Ozbek (2004) J Laryngol Otol 118:439-42
10. Procedure: Needle Aspiration
    1. Primary anesthetic
       1. Step 1: Spray with topical anesthetic
          1. Benzalkonium 0.5% spray (Cetacaine)
       2. Step 2: Gargle 2% Lidocaine with Epinephrine
    2. Alternative anesthetic: Sphenopalatine block
       1. Lidocaine or Cocaine soaked pledget
       2. Place under posterior aspect of middle turbinate
    3. Needle Aspiration Technique
       1. Spinal needle 18 gauge on 10 cc syringe
       2. Consider needle guard
          1. Prevents entrance into Carotid Artery
          2. Needle should protrude only 0.5 cm beyond guard
          3. Cut off distal 0.5 cm of plastic needle cover
          4. Tape needle cover to syring to secure
       3. Avoid lateral margin of tonsil
          1. Carotid Artery is 2.5 cm posterolateral to tonsil
          2. Keep needle in sagittal plane
       4. Aspirate most fluctuant area
          1. Superior pole of tonsil most commonly affected
          2. Aspirate peritonsillar space (medial Soft Palate)
             1. Tonsil itself is not aspirated
    4. Complications
       1. Patient aspiration of pus or blood
       2. Hemorrhage from puncture of Carotid Artery
11. Complications
    1. Airway obstruction
    2. Lung infection (Aspiration Pneumonia or Lung Abscess) from Peritonsillar Abscess rupture
    3. Erosion into Carotid Artery sheath (uniformly fatal)
    4. Deep neck infection from contiguous spread
12. Follow-up
    1. Tonsillectomy 3-6 months after Peritonsillar Abscess
13. References
    1. Roberts (1998) Procedures Emergency Medicine, p. 1122-6
    2. Brook (2004) J Oral Maxillofac Surg 62:1545-50
    3. Kieff (1999) Otolaryngol Head Neck Surg 120(1):57-61
    4. Steyer (2002) Am Fam Physician 65(1):93-96