Peritonsillar Abscess

Aka: Peritonsillar Abscess, Peritonsillitis, Peritonsillar Cellulitis, Quinsy Sore Throat

1. See Also
   1. Pharyngitis
   2. Pharyngitis Causes
   3. Dysphagia
   4. Tonsillitis
   5. Group A Streptococcal Pharyngitis
   6. Retropharyngeal Abscess
   7. Lemierre Syndrome
   8. Diphtheria
   9. Chronic Pharyngeal Carriage of Streptococcus pyogenes
   10. Tonsillectomy Indications
2. Epidemiology
   1. Highest Incidence ages 20-40 years old
3. Pathophysiology
   1. Sequelae of acute Tonsillitis or Tonsillopharyngitis
   2. Progression from exudative Tonsillitis to Peritonsillar Cellulitis to Peritonsillar Abscess
      1. Weber's Glands (mucous Salivary Glands within Soft Palate)
         1. Reside in Soft Palate, superior to Tonsil
         2. Duct between Weber Gland and Tonsil
      2. Cellulitis develops within the Weber Gland
      3. Weber Gland duct obstructs and abscess forms
4. Risk Factors
   1. Exudative Tonsillitis
   2. Periodontal Disease
   3. Tobacco Abuse
5. Etiology
   1. Group A Streptococcal Pharyngitis complication
      1. Streptococcus Pyogenes (most common aerobic organism)
   2. Mixed oropharyngeal flora
      1. Staphylococcus aureus
      2. Corynebacterium
      3. Streptococcus milleri (S. intermedius, S. anginosus, S. constellatus)
      4. HaemophilusInfluenzae
      5. Neisseria
      6. Anaerobic Bacteria
         1. Fusobacterium
         2. Peptostreptococcus
         3. Prevotella
         4. Bacteroides
6. Symptoms
   1. Fever
      1. Temp over 39.4 F suggests more serious infection (parapharyngeal space infection, Sepsis)
   2. Severe, unilateral throat pain
   3. Dysphagia and Odynophagia (difficult and painful swallowing)
   4. Malaise
   5. Otalgia (ipsilateral to abscess)
7. Signs
   1. General
      1. Ill appearance
      2. Muffled ("hot potato") voice
      3. Trismus
      4. Drooling
   2. Oropharynx
      1. Uvula deviates to the opposite side
      2. Localized swelling of Soft Palate over affected Tonsil
   3. Swollen Tonsil (usually superior pole)
      1. Indurated, fluctuant mass
      2. Exudate may be present
      3. Erythematous peritonsillar area
      4. Usually unilateral
8. Labs
   1. Complete Blood Count (CBC)
   2. Throat Culture
   3. Streptococcal Rapid Antigen Test
   4. Monospot
9. Imaging
   1. Indications
      1. Confirm Peritonsillar Abscess
         1. Diagnosis is uncertain
         2. Failed aspiration (Ultrasound)
      2. Evaluate contiguous soft tissues and vessels (CT or MRI)
         1. Significant Trismus
         2. Suspected deep space infection
   2. Neck Ultrasound
      1. Preferred imaging modality for diagnosis and aspiration guidance
      2. Endocavitary probe transducer intraoral (preferred)
         1. Alternatively, may attempt visualization over Submandibular Gland
      3. Abscess is echo-free with irregular border
   3. CT Neck with contrast
      1. Abscess appears with low attenuation
      2. High False Positive Rate for Peritonsillar Abscess
      3. Shows contiguous spread of infection to deep neck tissue
   4. MRI neck
      1. Evaluate for deep neck infections (better than CT)
      2. Evaluate internal Jugular Vein thrombosis and Carotid Artery sheath erosion
10. Differential Diagnosis
    1. Peritonsillar Cellulitis (no pus in capsule)
    2. Retropharygeal abscess
    3. Dental Infection (e.g abscessed tooth, Retromolar abscess)
    4. Epiglottitis
    5. Mononucleosis (up to 6% coinfection, esp. in teens and young adults)
    6. Cervical adenitis
    7. Sialolithiasis or Sialadenitis
    8. Mastoiditis
    9. Internal cartoid artery aneurysm
    10. Malignancy (e.g. Lymphoma)
11. Management
    1. Needle aspiration
       1. See Needle Aspiration technique below
       2. Be prepared for airway emergency
       3. Observe patient for several hours after observation and confirm able to tolerate liquids
       4. Failed aspiration of pus
          1. May be consistent with Peritonsillar Cellulitis
          2. Consider imaging soft tissue for deep space infection
          3. If no serious findings, may discharge home with close follow-up on oral medications
    2. Disposition: Indications for inpatient management (typically 2-4 day stays)
       1. Children
       2. Dehydration
       3. Toxic appearance
       4. Persistent significant Trismus or Dysphagia (refractory to aspiration)
       5. Airway compromise risk (e.g. kissing Tonsils)
    3. Disposition: Outpatient Management
       1. Observe after aspiration for several hours before discharge (confirm tolerating liquids)
       2. Prescribe antibiotics, Corticosteroids (typically) and Analgesics
       3. Close interval follow-up at 24-36 hours
    4. Antibiotics for 10-14 days
       1. Broad spectrum antibiotics are typically needed (polymicrobial infections, often with resistance)
          1. May adjust antibiotic based 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. Piperacillin/Tazobactam (Zosyn) 3.375 mg every 6 hours
          3. Ampicillin with Sulbactam (Unasyn) 3 grams every 6 hours
          4. Ceftriaxone 1 g every 12 hours AND Metronidazole
          5. Clindamycin 900 mg IV every 8 hours (if Penicillin allergic)
          6. Consider Vancomycin AND Flagyl if MRSA concern
       3. Oral agents
          1. Clindamycin 300 to 450 mg orally every 8 hours
          2. Cefdinir (Omnicef) 300 mg every 12 hours AND Metronidazole
          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
    5. Corticosteroids as adjunct to antibiotics
       1. Dexamethasone 10 mg orally for 1 dose
          1. O'Brien (1993) Ann Emerg Med 22(2): 212-5 [PubMed]
       2. Depo Medrol 2-3 mg/kg up to 250 mg IV for 1 dose
          1. Patients improved faster when adjunctive steroids were used
          2. Ozbek (2004) J Laryngol Otol 118:439-42 [PubMed]
       3. Efficacy
          1. Decreased pain and improved oral intake within 12-24 hours
          2. Faster recovery and shorter hospital stays
          3. Lee (2016) Clin Exp Otorhinolaryngol 9(2): 89-97 [PubMed]
12. Procedure: Needle Aspiration
    1. Precautions
       1. Carotid Artery runs 2 cm posterolateral to Tonsillar Pillar
       2. Do not insert aspiration needle more than 8 mm
    2. Primary anesthetic
       1. Step 1: Spray with topical anesthetic
          1. Benzalkonium 0.5% spray (Cetacaine)
       2. Step 2: Gargle 2% Lidocaine with Epinephrine
       3. Alternative anesthetic
          1. Sphenopalatine block
             1. Lidocaine or Cocaine soaked pledget
             2. Place under posterior aspect of middle turbinate
          2. Local anesthetic injection
             1. Inject into mucosa overlying region of fluctuance using 25-27 g 1.5 inch needle OR
             2. Inject Lidocaine into mucosa with aspiration needle and then aspirate
    3. Preparation
       1. Be prepared for airway emergency (e.g. bleeding)
       2. Suction with Yanker tip
       3. Light source: Direct Laryngoscope with curved blade
          1. Position overlying the Tongue, lighting the posterior pharynx, but not so deep as to trigger a Gag Reflex
       4. Patient as assistant (if sufficiently calm)
          1. Patient may hold shallowly placed Laryngoscope Blade in place with one of their hands
          2. Patient may hold the suction catheter with their opposite hand
       5. Patient positioning
          1. Patients sits forward, at eye level to examiner
       6. Ultrasound with endocavitary probe
          1. Helps to guide needle towards largest abscess pocket
          2. Trismus may limit use
       7. References
          1. Lin in Herbert (2014) EM:Rap 14(4): 5-7
    4. Needle Aspiration Technique
       1. Retract Tongue
          1. Tongue blade or
          2. Laryngoscope Blade (consider having patient hold this, see above)
       2. Spinal needle 18 gauge on 3 cc syringe
          1. Longer spinal needle obstructs view less
          2. Smaller syringe requires less force to withdraw plunger
       3. 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 syringe to secure
       4. Avoid lateral margin of Tonsil
          1. Carotid Artery is 2 to 2.5 cm posterolateral to Tonsil
          2. Keep needle in sagittal plane
       5. 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
       6. Failed aspiration
          1. Move the needle inferolaterally along the Soft Palate and reattempt aspiration up to twice more
          2. Exercise caution, as carotid puncture increases in risk with inferior needle placement
    5. Complications
       1. Patient aspiration of pus or blood
       2. Hemorrhage from puncture of Carotid Artery
13. 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 or mediastinal infection from contiguous spread
14. Follow-up
    1. Consider Tonsillectomy 3-6 months after Peritonsillar Abscess (40% recurrence rate)
15. References
    1. Roberts (1998) Procedures Emergency Medicine, p. 1122-6
    2. Swadron and Finley in Herbert (2018) EM:Rap 18(7): 3-4
    3. Brook (2004) J Oral Maxillofac Surg 62:1545-50 [PubMed]
    4. Galioto (2017) Am Fam Physician 95(8): 501-6 [PubMed]
    5. Kieff (1999) Otolaryngol Head Neck Surg 120(1):57-61 [PubMed]
    6. Steyer (2002) Am Fam Physician 65(1):93-96 [PubMed]