Pharyngitis — Empiric Antibiotic Therapy — Clinical Pathway: Emergency Department and Inpatient

Suspected Pharyngitis or Peritonsillar Abscess (PTA) Clinical Pathway — Emergency Department and Inpatient

Empiric Antibiotic Therapy for Pharyngitis and Peritonsillar Abscess

General Principles

  • Empiric antibiotic options are based on the most common pathogens.
  • Streptococcus pyogenes is universally susceptible to penicillin.
  • Rapid strep testing is highly sensitive:
    • GAS colonization is common among children.
    • Children without symptoms consistent with pharyngitis should not be tested or treated.
  • Children should only be treated for Streptococcal pharyngitis if they have a positive test (either rapid strep testing or positive culture). If rapid strep testing is negative, children should not be empirically treated with antibiotics pending culture results.
  • The recommended duration of therapy is 10 days for most antimicrobials for pharyngitis. If benzathine penicillin is given intramuscularly, therapy is complete after a single dose.
  • Peritonsillar abscess is generally treated for 10-14 days, depending on clinical course and source control.
Pharyngitis Peritonsillar Abscess
Streptococcus pyogenes
  • Streptococcus pyogenes
  • Oral anaerobes (e.g., Fusobacteria, Prevotella, Veillonella species)
  • Staphylococcus aureus, including MRSA

Empiric Antibiotic Recommendations

Indication First-Line Therapy Allergy to First-Line β-Lactam
Assess Need for Alternative
Group A streptococcal pharyngitis
  • Amoxicillin, PO
    • 50 mg/kg/day divided once or twice daily
    • Max: 1,000 mg/day
  • or
  • Penicillin VK, PO
    • Children ≤ 27 kg:
    • 250 mg/dose two times daily
    • Children > 27 kg, adolescents, and adults:
    • 500 mg two times daily
  • Children who cannot tolerate enteral therapy:
    Benzathine Penicillin G, IM
    • Children < 27 kg
    • 0.6 million units as a single dose
    • Children ≥ 27 kg, adolescents, and adults
    • 1.2 million units as a single dose
  • Cephalexin, PO
    • 20 mg/kg/dose twice daily
    • Max: 500 mg/dose
Peritonsillar abscess or phlegmon
  • Ampicillin/sulbactam, IV
    • 50 mg ampicillin/kg/dose every 6 hours
    • Max: 2,000 mg ampicillin/dose
  • or
  • Amoxicillin/clavulanate, PO
    • 22.5 mg amoxicillin/kg/dose every 12 hours
    • Max: 875 mg amoxicillin/dose
  • Clindamycin, IV
    • 10 mg/kg/dose every 8 hours
    • Max: 2,700 mg/day
  • or
  • Clindamycin, PO
    • 10 mg/kg/dose three times daily
    • Max: 600 mg/dose

CHOP Formulary for complete drug information.