What is the appropriate evaluation and management of a retropharyngeal abscess?

Retropharyngeal Abscess: Evaluation and Management

Immediate Airway Assessment

The first priority in retropharyngeal abscess is securing the airway, as this is a potentially life-threatening infection that can cause rapid airway compromise. 1

• Assess for signs of airway obstruction: respiratory distress, stridor, drooling, inability to swallow, hoarseness, or severe dysphagia 2, 1
• If airway compromise is suspected, immediately secure the airway in a controlled environment with both an otolaryngologist and anesthesiologist present 1
• Be prepared for difficult intubation (grade 3 or higher) due to anatomical distortion from the abscess 1
• Tracheotomy is rarely required but may be necessary in severe cases 3, 4

Diagnostic Evaluation

Clinical Presentation

• Classic symptoms include: fever, neck pain, restricted cervical mobility, dysphagia, pharyngitis, and neck swelling 5, 2, 3
• In adults, presentation may be atypical with neck fullness, shoulder pain, or abdominal pain, making diagnosis more challenging 2
• In children under 5 years, RPA typically follows upper respiratory or oropharyngeal infections 5
• In adults, consider trauma, foreign body ingestion, dental infections, or medical instrumentation as causative factors 5, 2

Imaging

Contrast-enhanced CT of the neck is the gold standard for diagnosis and should be obtained in all suspected cases. 5, 3

• Lateral neck radiograph showing widening of the prevertebral space (>7mm at C2 or >14mm at C6 in children) is a useful initial screening tool but CT is preferred 5
• CT provides accurate anatomical localization, abscess volume measurement, and identifies complications such as extension into the mediastinum or spinal canal 5, 3
• MRI may be used in select cases, particularly for abscesses near the skull base 3
• 72% of pediatric otolaryngologists prefer CT as their diagnostic method of choice 4

Microbiological Sampling

• Obtain two sets of blood cultures before initiating antibiotics 6
• If surgical drainage is performed, send purulent material for Gram stain, aerobic and anaerobic cultures 5, 3
• Streptococcus pyogenes is the most commonly isolated pathogen, though polymicrobial infections are common 5, 3

Treatment Strategy

Antibiotic Therapy

Initiate broad-spectrum intravenous antibiotics immediately covering Gram-positive, Gram-negative, and anaerobic bacteria. 7

• Recommended empiric regimens:
  • Ampicillin-sulbactam or piperacillin-tazobactam PLUS vancomycin (for MRSA coverage) 2
  • Alternative: Clindamycin (covers anaerobes and streptococci) 8
• More aggressive antibiotic therapy is required for patients with systemic signs of infection or immunocompromised status 7
• Avoid aminoglycosides as they achieve poor penetration into abscess cavities and are inactive in acidic environments 6

Medical vs. Surgical Management Decision Algorithm

The decision between medical management alone versus surgical drainage depends on abscess characteristics and clinical response:

Trial of IV Antibiotics Alone (Conservative Management)

• Consider in: small abscesses (<2-3 cm³), no airway compromise, and stable clinical condition 4
• 20-40% of retropharyngeal abscesses may resolve with antibiotics alone according to pediatric otolaryngology practice patterns 4
• Monitor closely for 24-48 hours with serial clinical assessments 4

Indications for Surgical Drainage

• Immediate drainage required if:
  • Airway compromise or impending airway obstruction 1, 3
  • Large abscess volume (>9 cm³ mean in surgical series) 3
  • Clinical deterioration or persistent fever despite 24-48 hours of appropriate IV antibiotics 3, 4
  • Extension into dangerous spaces (mediastinum, spinal canal) 5, 3

Surgical Approaches

Transoral incision and drainage is the preferred surgical technique in 83% of cases. 4

• Transoral approach: preferred for midline abscesses accessible through the oropharynx 3, 4
• Transcervical approach: indicated for lateral abscesses, large collections, or those extending below C6 3
• Combined transoral and transcervical: may be necessary for extensive abscesses 3
• Transnasal endoscopic approach: reserved for abscesses close to the skull base, ideally with MRI guidance 3

Complications and Pitfalls

Life-Threatening Complications

• Airway obstruction is the most immediate threat requiring urgent intervention 1
• Mediastinitis from inferior extension 8
• Necrotizing fasciitis 8
• Spinal canal abscess (rare but reported) 5
• Septic thrombophlebitis with pulmonary emboli 8

Common Pitfalls to Avoid

• Do not delay airway management in patients with respiratory distress—secure the airway first, then proceed with imaging and definitive treatment 1
• Do not confuse with peritonsillar abscess or parapharyngeal abscess, which have different anatomical locations and management approaches 8
• Do not rely solely on clinical examination—imaging is essential as physical findings may be subtle, especially in adults 2
• Do not assume foreign body has been excluded without careful history and imaging review, as unusual foreign bodies can cause RPA in children 5

Post-Treatment Monitoring

• Continue IV antibiotics for at least 2 weeks based on culture sensitivities 1
• Monitor for recurrence (occurs in approximately 5% of cases) 5
• Short-term intubation (24-72 hours) is rarely required postoperatively 4
• Ensure complete resolution with clinical follow-up; repeat imaging is not routinely necessary unless clinical deterioration occurs 3