Retropharyngeal Abscess

Epidemiology and Etiology

Epidemiology

• Most common in children < 5 years of age
• Less common in adults (due to regression of the retropharyngeal lymph nodes)
• More common in males than females

Etiology

• Abscesses occur due to infections that drain to lateral retropharyngeal lymph nodes.
• May be secondary to: 
  • Upper respiratory tract infections (more common in children) 
  • Otitis media
  • Sinusitis
  • Pharyngeal trauma (more common in adults) 
    • Foreign body (e.g., fishbone)
    • Endoscopy
    • Dental procedures
• Infections are often polymicrobial and may include: 
  • Aerobes
    • Staphylococcus aureus 
    • Streptococcus pyogenes
  • Anaerobes 
    • Bacteroides 
    • Fusobacteria

Clinical Presentation

Early symptoms

• May mimic pharyngitis
  • Fever
  • Sore throat
  • Pharyngeal erythema
• Dysphagia
• Odynophagia
• Neck stiffness/asymmetry 
• Trismus (lockjaw)

Later symptoms

• Ill-appearing, drooling
• “Sniffing” position: leaning forward with neck extended
• Respiratory distress: 
  • Tachypnea 
  • Stridor
  • Nasal flaring
  • Subcostal retractions

Diagnosis and Management

Diagnosis

• Initial work-up includes:
  • CBC
  • Blood culture
• Diagnosis is confirmed by imaging.
  • Lateral neck X-ray:
    • Widened retropharyngeal space 
    • Gas in the retropharyngeal space
  • Computed tomography (CT) of the neck with contrast (gold standard):
    • Rim-enhancing hypodense collection in retropharyngeal space
    • Thickening of the prevertebral space 
    • Presence of air or air-fluid levels

Management

• The 1st and most important step is protecting the airway → intubation if needed! 
• Surgical drainage
• Antibiotics
  • Ampicillin/sulbactam or clindamycin
  • If no response, vancomycin or linezolid

Complications

Retropharyngeal abscesses are considered the most deadly deep neck infection. 

The most common complications include:

• Mediastinitis
  • Occurs due to extension into the posterior mediastinum through the “danger space” → space that allows direct spread to the thorax
  • Can progress to acute necrotizing mediastinitis
  • Mortality rate of 50%
• Internal jugular vein thrombosis 
• Carotid artery rupture → due to extension of the carotid sheath
• Airway obstruction
• Septicemia
• Epidural abscess or diskitis

Differential Diagnosis

• Epiglottitis: an inflammation of the epiglottis most commonly caused by infection with Haemophilus influenzae. Epiglottitis presents with “cherry-red” epiglottis, fever, dysphagia, drooling, and difficulty breathing. The condition is commonly seen in unvaccinated children. Treatment is with rocephin and steroids.
• Peritonsillar abscess: a bacterial infection (most commonly S. pyogenes) that causes an abscess next to the palatine tonsils. The condition is more common in children and young adults and presents with trismus, fever, and sore throat, with a “hot potato” voice. Physical exam shows an abscess near the pharyngeal tonsil causing uvula deviation. Treatment is with antibiotics and surgical drainage. 
• Parapharyngeal abscess or prevertebral space infection: very similar clinical presentation to retropharyngeal abscesses but most often caused by dental infections that extend into the lateral or posterior pharyngeal space. The best way to differentiate pharyngeal from retropharyngeal abscess is by CT of the neck. Treatment is with antibiotics and surgical drainage. 
• Meningitis: an infection of the meninges, the protective membranes around the brain, most often caused by Streptococcus pneumoniae or H. influenzae. Meningitis presents with fever, stiff neck, and headache. The condition is differentiated from retropharyngeal abscess by the presence of light sensitivity, headache, and nuchal rigidity. Diagnosis is by lumbar puncture for cerebrospinal (CSF) evaluation. Treatment consists of the rapid administration of antibiotics.