Pharyngitis

Background

• Inflammation or infection of the pharynx

Microbiology

• Viruses (most common)
  • Rhinovirus
  • Coronavirus
  • Enterovirus
  • HIV
  • EBV
  • CMV
  • Adenovirus
  • HSV
• Bacteria
  • Streptococcus pyogenes (most important bacterial cause)
  • Fusobacterium necrophorum, with risk of Lemierre syndrome
  • Arcanobacterium haemolyticum
  • Corynebacterium diphtheriae, causing diphtheria
  • Neisseria gonorrhoeae

Clinical Manifestations

• Sore throat with or without fevers
• Streptococcal pharyngitis may result in lymphadenitis, sinusitis, otitis media, mastoiditis, necrotizing fasciitis, toxic shock syndrome, acute rheumatic fever, and post-infectious glomerulonephritis

Centor Criteria

• The Centor criteria help to identify those at risk of streptococcal pharyngitis who may benefit from antibiotics
• Used in patients with onset of symptoms within the last 3 days
• Criteria
  • One point for each of:
    • Age 3 to 14 years
    • Exudate or swelling of tonsils
    • Tender or swollen anterior cervical lymph nodes
    • Temperature >38ºC
  • Remove one point for age ≥45 years
• Interpretation:
  • 0 points: 1-2.5% risk; no antibiotics
  • 1 point: 5-10% risk; no antibiotics
  • 2 points: 11-17% risk; optional rapid strep testing or culture
  • 3 points: 38-35% risk; consider rapid strep testing or culture
  • ≥4 points: 51-53% risk; consider rapid strep testing or culture as well as empiric antibiotics

Management

• Most common cause is viral, which requires supportive care
• To estimate risk of streptococcal pharyngitis, apply the Centor criteria, described above
  • 0-1 points: no further tests
  • 2-4 points: consider ruling out streptococcal pharyngitis with rapid test or culture, with treatment if positive
  • ≥4 points: consider empiric treatment