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Retropharyngeal Abscess

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Retropharyngeal Abscess, Parapharyngeal Abscess, Parapharyngeal Space Infection

  • Definitions
  1. Parapharyngeal Abscess
    1. Purulent collection within pharygeal spaces (lateral pharynx, retropharynx, pretracheal spaces)
    2. Sources include sinuses and middle ear, teeth and Tonsils, as well as Salivary Glands (esp. Parotid Gland)
    3. Oral foreign bodies (e.g. fish bones) may also serve as source
    4. May spread to involve submandibular space (Ludwig's Angina)
  2. Retropharyngeal Abscess
    1. Purulent collection between pharynx and Cervical Spine
    2. Typically occurs from Trauma or URI spread to retropharyngeal lymph nodes
  • Epidemiology
  1. Disease of infants and young children (age <4-6 years old)
    1. Young children have prominent retropharyngeal lymph nodes
  • Pathophysiology
  1. Retropharyngeal lymph nodes not atrophied in children
  2. Accumulation of pus in retropharyngeal space
  3. Mixed aerobic and anaerobic flora
  • Risk Factors
  1. Children under age 6 years
  2. Upper airway Trauma (see causes below)
  3. Immunocompromised Condition
    1. HIV Infection
    2. Diabetes Mellitus
  • Causes
  • Mechanism
  1. Upper Respiratory Infection (more common cause in children)
    1. Sources: Dental Infection, Tonsillitis, parotid Sialadenitis, middle ear infections, Acute Sinusitis
    2. Spreads posteriorly to retropharyngeal lymph nodes
  2. Trauma (adults and children)
    1. Vertebral Fracture
    2. Fish bone ingestion
    3. Upper airway instrumentation (Endotracheal Intubation, Nasogastric Tube placement)
  • Causes
  • Organisms
  1. Common Causes
    1. Group A Streptococcus
    2. Viridans Streptococcus
    3. Anaerobic Bacteria (e.g. Fusobacterium)
  2. Less common causes
    1. Staphylococcus aureus including MRSA (less common)
    2. HaemophilusInfluenzae (less common after use of Hib Vaccine)
    3. Tuberculosis (esp. in HIV Infection)
    4. Pseudomonas aeruginosa in high risk groups (e.g. Diabetes Mellitus, IV Drug Abuse, Neutropenia)
  • Symptoms
  1. Neck Pain (out of proportion to findings)
  2. Dysphagia
  3. Odynophagia
  4. Drooling
  5. Fever
  6. Palliative measures
    1. Patients prefer supine position (less encroachment on airway)
  • Signs
  1. May be difficult to appreciate pharyngeal fullness
  2. Airway compromise may be present
    1. Respiratory distress (e.g. Tachypnea)
    2. Inspiratory Stridor
    3. Muffled voice or hot potato voice
  3. Torticollis
  4. Trismus
  • Differential Diagnosis
  • Imaging
  1. Lateral neck XRay
    1. Bulging of posterior pharyngeal wall
    2. Prevertebral soft tissue width increased
      1. C2 level prevertebral space >7 mm (adults and children)
      2. C6 level prevertebral space >14 mm (children) or >22 mm (adults)
  2. CT or MRI Neck
    1. May demonstrate abscess extent
  • Management
  1. Hospitalize
  2. Airway observation
    1. Endotracheal Intubation required in up to one third of cases
  3. Early, emergent ENT Consultation for surgical drainage
    1. Incision and Drainage in operating room
  4. Intravenous Antibiotics
    1. Duration (total treatment course): 2-3 weeks
    2. Initial empiric antibiotics
      1. Clindamycin 600-900 mg IV every 8 hours and Levofloxacin 750 mg IV every 24 hours OR
      2. Ceftriaxone 2 g IV every 24 hours AND Metronidazole 1 g IV every 12 hours OR
      3. Ampicillin-Sulbactam (Unasyn) 3 g IV every 6 hours
    3. Staphyococcus aureus detected
      1. Add Vancomycin
    4. Pseudononas coverage
      1. Piperacillin-Tazobactam (Zosyn) 3.375 g IV every 6 hours OR
      2. Cefepime and Metronidazole
  • Complications
  1. Airway obstruction (most common fatal complication)
  2. Ludwig's Angina
  3. Atlantoaxial separation (transverse ligament erosion)
  4. Carotid Artery erosion
  5. Jugular Vein thrombosis
    1. Secondary risk of septic Thrombophlebitis (and Lemierre Syndrome)
  6. Necrotizing Mediastinitis
  7. Meningoencephalitis
  8. Esophageal Perforation
  9. Horner Syndrome
  10. Cranial Nerve palsy (CN 9, CN 10, CN 11, CN 12)
  • References
  1. Aldden and Rosenbaum (2017) Emergency Medicine Board Review, Wolters Kluwer
  2. (2020) Sanford Guide, accessed 1/19/2020