Retropharyngeal Abscess

RPA Intro - Neck's Deep Danger

• Pus in retropharyngeal space (RPS): potential space between posterior pharyngeal wall & prevertebral fascia.
• Peak incidence: children < 5 years.
• Children: Often due to suppuration of retropharyngeal lymph nodes (of Rouviere) post-URTI.
• Adults: Typically from trauma (e.g., instrumentation) or spread from adjacent deep neck infections.

⭐ Retropharyngeal lymph nodes (of Rouviere) usually atrophy by age 4-5, making primary RPA via lymphadenitis rarer in older individuals.

RPA Origins - Bug's Bad Breach

• Etiology:
  • Children: Lymphadenitis (retropharyngeal nodes) post-URI (pharyngitis, tonsillitis, otitis).

    ⭐ In children, RPA most commonly arises from suppuration of retropharyngeal lymph nodes secondary to upper respiratory tract infections (pharyngitis, tonsillitis, otitis media).

  • Adults: Penetrating trauma (e.g., fishbone, procedures), contiguous spread (deep neck/vertebral infection).
• Microbiology (Often Polymicrobial):
  • Common: Strep. pyogenes (GAS), Staph. aureus, anaerobes (Bacteroides, Peptostreptococcus).
  • Others: H. influenzae, Klebsiella, M. tuberculosis (Pott's).

RPA Alarms - Throat's Red Alert

• Fever: Often high-grade, sudden onset.
• Neck:
  • Hyperextension or torticollis (head tilted).
  • Stiffness, pain, or swelling.
• Drooling/Dysphagia: Difficulty or pain on swallowing.
• Voice: Muffled, "hot potato" quality (cri du canard).
• Respiratory Distress:
  • Stridor (inspiratory, a late and ominous sign ⚠️).
  • Tachypnea, nasal flaring.
• General: Irritability, restlessness, poor feeding (especially in infants).
• Physical Exam: Posterior pharyngeal wall bulge (often unilateral).

⭐ Key symptoms in children include fever, neck hyperextension or torticollis, drooling, dysphagia, and a muffled 'hot potato' voice; stridor is a late and ominous sign.

RPA Reveal - Scan & See

• Lateral Neck X-ray (Soft Tissue):
  • Widened prevertebral space (↑): >7mm at C2; >14mm (child) or >22mm (adult) at C6.
  • May show air-fluid level, loss of cervical lordosis.
• CECT Neck:
  • Gold standard. Differentiates abscess/cellulitis.
  • Key findings: Rim enhancement, scalloping, central low attenuation (↓density core), ± gas.
• MRI:
  • Alternative if CECT contraindicated or for suspected complications (e.g., osteomyelitis, epidural abscess).

⭐ Contrast-enhanced CT scan is the gold standard for diagnosis, differentiating abscess from cellulitis and defining the extent of infection.

RPA Rescue - Drain & Drug

• Airway management: Secure airway first (intubation if needed).
• Broad-spectrum IV antibiotics:
  • Clindamycin
  • Ampicillin-sulbactam
  • Ceftriaxone + Metronidazole
• Consult ENT for surgical drainage if abscess is fluctuant or >2.5 cm.

⭐ Management priorities are airway security (ABC), intravenous antibiotics (e.g., Clindamycin or Ampicillin-Sulbactam), and surgical drainage for fluctuant abscesses.

RPA Risks - Spread & Scare

• Local Spread:
  • Airway obstruction (most feared!)
  • Aspiration pneumonia
  • Pharyngeal/laryngeal edema
• Distant Spread:
  • Mediastinitis (via 'danger space')
  • Internal jugular vein thrombosis (Lemierre's syndrome)
  • Carotid artery erosion
  • Sepsis

⭐ Airway obstruction is the most feared complication; spread to the 'danger space' can lead to life-threatening mediastinitis.

High‑Yield Points - ⚡ Biggest Takeaways

• Primarily affects children < 6 years due to lymphadenitis of retropharyngeal nodes.
• Presents with acute fever, dysphagia, drooling, neck stiffness, muffled voice, and potential stridor.
• Lateral neck X-ray: Shows widened prevertebral space (>7mm at C2).
• CT scan with IV contrast is gold standard for diagnosis and assessing extent.
• Airway obstruction is the most feared, life-threatening complication.
• Management: Secure airway, IV antibiotics, and prompt surgical drainage.