Peritonsillar Abscess

See Also

Epidemiology

Highest Incidence ages 20-40 years old
Accounts for 30% of head and neck abscesses

Pathophysiology

Sequelae of Acute Tonsillitis or Tonsillopharyngitis
Abscess forms between lateral Tonsil and pharyngeal constrictor Muscles
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

Risk Factors

Causes

Group A Streptococcal Pharyngitis complication
1. Streptococcus Pyogenes (most common aerobic organism)
Mixed oropharyngeal flora
1. Staphylococcus aureus
2. Corynebacterium
3. Streptococcus milleri (S. intermedius, S. anginosus, S. constellatus)
4. Haemophilus Influenzae
5. Neisseria
6. Anaerobic Bacteria
  1. Fusobacterium
  2. Peptostreptococcus
  3. Prevotella
  4. Bacteroides
  5. Porphyromonas

Symptoms

Fever
1. Temp over 39.4 F suggests more serious infection (Parapharyngeal Space Infection, Sepsis)
Severe, unilateral throat pain
Dysphagia and Odynophagia (difficult and painful Swallowing)
Malaise
Otalgia (ipsilateral to abscess)

Signs

General
1. Ill appearance
2. Muffled ("hot potato") voice
3. Trismus
4. Drooling
5. Tender Cervical Lymphadenopathy
Oropharynx
1. Uvula deviates away from abscess to the opposite side
2. Localized swelling of Soft Palate over affected Tonsil
Swollen Tonsil (usually superior pole)
1. Indurated, fluctuant mass
2. Exudate may be present
3. Erythematous peritonsillar area
4. Usually unilateral

Labs

Imaging

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
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
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
MRI neck
1. Evaluate for deep neck infections (better than CT)
2. Evaluate Internal Jugular Vein Thrombosis and Carotid Artery sheath erosion

Differential Diagnosis

Peritonsillar Cellulitis (no pus in capsule)
Retropharygeal abscess
Dental Infection (e.g abscessed tooth, Retromolar abscess)
Epiglottitis
Mononucleosis (up to 6% coinfection, esp. in teens and young adults)
Cervical adenitis
Sialolithiasis or Sialadenitis
Mastoiditis
Internal cartoid artery aneurysm
Malignancy (e.g. Lymphoma)

Management

Needle aspiration
1. See Peritonsillar Abscess Needle Aspiration
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
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)
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
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
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]

Complications

Airway obstruction
Lung infection (Aspiration Pneumonia or Lung Abscess) from Peritonsillar Abscess rupture
Erosion into Carotid Artery sheath (uniformly fatal)
Internal jugular vein Thrombophlebitis
Deep neck or mediastinal infection from contiguous spread

Follow-up

Consider Tonsillectomy 3-6 months after Peritonsillar Abscess (40% recurrence rate)

References

Anderson (2019) Crit Dec Emerg Med 33(9): 3-10
Roberts (1998) Procedures Emergency Medicine, p. 1122-6
Swadron and Finley in Herbert (2018) EM:Rap 18(7): 3-4
Brook (2004) J Oral Maxillofac Surg 62:1545-50 [PubMed]
Galioto (2017) Am Fam Physician 95(8): 501-6 [PubMed]
Kieff (1999) Otolaryngol Head Neck Surg 120(1):57-61 [PubMed]
Steyer (2002) Am Fam Physician 65(1):93-96 [PubMed]