What is the best treatment approach for a patient presenting with symptoms of either a peritonsillar abscess or a retropharyngeal abscess, including severe throat pain, difficulty swallowing, and fever?

Peritonsillar Abscess vs Retropharyngeal Abscess: Diagnosis and Management

For patients presenting with severe throat pain, dysphagia, and fever, immediately assess for airway compromise and perform a focused examination to distinguish between peritonsillar abscess (PTA)—which presents with unilateral tonsillar bulge, uvular deviation, and trismus—versus retropharyngeal abscess (RPA)—which presents with neck stiffness, posterior pharyngeal wall bulge, and often occurs in younger patients or following pharyngeal trauma. 1, 2, 3

Immediate Assessment Priorities

Airway Evaluation

• Assess for airway obstruction immediately: Look for drooling, inability to swallow secretions, stridor, respiratory distress, or severe trismus that prevents oral examination 1, 2
• Patients with these findings require urgent ENT consultation and potential airway management before further diagnostic workup 3, 4

Key Distinguishing Clinical Features

Peritonsillar Abscess: 3, 4

• Unilateral tonsillar swelling with medial displacement of the tonsil
• Uvular deviation away from the affected side
• Trismus (difficulty opening mouth)
• "Hot potato" or muffled voice
• Anterior cervical lymphadenopathy
• Most common in young adults and adolescents

Retropharyngeal Abscess: 5, 6

• Posterior pharyngeal wall bulge (midline or unilateral)
• Neck stiffness and pain with neck extension
• Less prominent trismus compared to PTA
• May have torticollis
• More common in young children but can occur in adults
• Risk of extension to parapharyngeal space

Diagnostic Approach

Clinical Diagnosis

• PTA can often be diagnosed clinically based on the characteristic unilateral tonsillar bulge, uvular deviation, and trismus without imaging 3, 4
• RPA requires imaging confirmation as clinical examination of the posterior pharyngeal wall may be limited, especially with trismus 5, 6

Imaging Indications

• Obtain CT scan with IV contrast for: 5, 6

  • Suspected retropharyngeal or parapharyngeal abscess
  • Atypical presentations of PTA
  • Failed initial drainage of PTA
  • Concern for deep neck space extension
  • Inability to adequately examine the oropharynx

• CT scan is the gold standard for confirming RPA and defining the extent of deep neck infections 5, 6

Treatment Algorithm

Peritonsillar Abscess Management

Immediate Intervention: 3, 4

1. Needle aspiration is the gold standard for both diagnosis and treatment of PTA
2. Perform aspiration at the point of maximal fluctuance (typically superior and lateral to the tonsil)
3. Send aspirate for aerobic and anaerobic culture

Antibiotic Therapy: 1, 3, 4

• Initiate antibiotics targeting Group A Streptococcus and oral anaerobes immediately after aspiration
• First-line options:
  • Amoxicillin-clavulanate 875 mg PO twice daily
  • Ampicillin-sulbactam 3g IV every 6 hours (if hospitalized)
• Penicillin allergy:
  • Clindamycin 300-450 mg PO three times daily or 600-900 mg IV every 8 hours 1, 3

Adjunctive Therapy: 5, 4

• Corticosteroids (dexamethasone 10 mg IV or oral equivalent) reduce symptoms and speed recovery
• Adequate hydration and pain control with NSAIDs or acetaminophen

Surgical Drainage Indications: 7, 3, 5

• Failed needle aspiration (no purulent drainage or symptom persistence after 24-48 hours)
• Recurrent PTA at the same site
• Consider immediate tonsillectomy for patients with >1 prior PTA episode 1

Retropharyngeal Abscess Management

Initial Treatment: 5, 6

1. Hospitalize all patients with confirmed RPA
2. IV antibiotics immediately:
   • Ampicillin-sulbactam 3g IV every 6 hours, OR
   • Clindamycin 600-900 mg IV every 8 hours plus ceftriaxone 1-2g IV daily
3. IV corticosteroids (dexamethasone 10 mg IV) to reduce inflammation 6

Drainage Decision: 5, 6

• Medical management alone may be sufficient for small abscesses (<2 cm) in children with close monitoring and follow-up CT scan at 21-45 days
• Surgical drainage required for:
  • Large abscesses (>2-3 cm)
  • Clinical deterioration despite 24-48 hours of IV antibiotics
  • Airway compromise
  • Extension to parapharyngeal space
  • Adults (lower threshold for surgical intervention)

Drainage approach: Transoral drainage or external cervical approach depending on abscess location and size 5, 6

Critical Pitfalls to Avoid

Diagnostic Errors

• Do not dismiss Lemierre syndrome in adolescents/young adults with severe persistent pharyngitis and high fever—this requires blood cultures and imaging of the neck vessels 1, 8
• Do not assume absence of fever rules out deep neck infection, especially in elderly, immunocompromised, or antibiotic-pretreated patients 8
• Do not rely solely on clinical exam for RPA—posterior pharyngeal examination is often limited and CT confirmation is essential 5, 6

Treatment Errors

• Do not use penicillin alone for PTA or RPA—anaerobic coverage is essential as these are polymicrobial infections with high incidence of anaerobes 7, 3, 4
• Do not delay drainage of confirmed abscesses—antibiotics alone are insufficient for established collections 3, 5
• Do not discharge patients with RPA for outpatient management—hospitalization with IV antibiotics is mandatory 5, 6

Monitoring Failures

• Monitor for jugular vein thrombosis in patients with parapharyngeal extension—this occurs in approximately 12% of cases and requires anticoagulation consideration 6
• Obtain follow-up imaging at 21-45 days for RPA treated medically to confirm resolution 6
• Watch for recurrence of PTA—patients with >1 episode should undergo tonsillectomy as definitive treatment 1, 2

Disposition

Outpatient management appropriate for: 4

• Uncomplicated PTA successfully drained with clinical improvement
• Able to tolerate oral intake and medications
• Reliable follow-up within 24-48 hours

Hospitalization required for: 5, 4, 6

• All retropharyngeal abscesses
• PTA with airway compromise, inability to tolerate oral intake, or failed outpatient management
• Concern for deep neck space extension
• Immunocompromised patients