Streptococcal Pharyngitis

Background

• Group A beta-hemolytic streptococcal pharyngitis is a common illness in children aged 5-15 years.
• It is usually benign but can have suppurative complications including acute otitis media, mastoiditis, bacterial meningitis, infective endocarditis, peritonsillar abscess, retropharyngeal abscess, bacteremia, cervical lymphadenitis, and pneumonia.
• Non-suppurative complications (immunogenic, particular to the Group A streptococcal bacteria) include acute rheumatic fever, poststreptococcal glomerulonephritis, toxic shock syndrome, and reactive arthritis.

Evaluation

• Consider using the Centor score or Modified Centor/McIsaac Score to assist in identifying patients who would not benefit from diagnostic testing (and treatment) for streptococcal pharyngitis.
  • 1 point for each of 4 criteria if present (history of fever, tonsillar exudate, tender anterior cervical lymphadenopathy, and absence of cough)
  • +1 point if age < 15 years and -1 point if age > 45 years
  • for management purposes, score of -1 treated as zero and a score of 5 treated as 4
• Avoid diagnostic testing if any of:
  • clinical presentation includes features strongly suggesting viral infection, such as conjunctivitis, rhinorrhea, cough, hoarseness, oral ulcers, diarrhea, or viral exanthem (Strong recommendation)
  • score ≤ 1 (Strong recommendation)
  • in most children < 3 years old (Strong recommendation)
• Obtain rapid antigen detection testing in patients with a Centor score ≥ 2 to confirm the diagnosis before treatment (Strong recommendation).
• Use of backup throat culture in patients with a negative rapid antigen detection test:
  • perform in children and adolescents (Strong recommendation)
  • not routinely indicated in adults (Strong recommendation)
• In adolescents and young adults presenting with sore throat and/or neck pain, particularly worsening symptoms after 4-5 days of onset, be alert to possibility of deep tissue throat infection or Lemierre syndrome. See also Lemierre Syndrome.

Management

• Offer supportive care (including analgesic measures, fluid intake) to patients with pharyngitis, but avoid aspirin in children (Strong recommendation).
• Limit antibiotics to patients with signs and symptoms suggestive of group A beta-hemolytic streptococcal (GABHS) infection and diagnosis confirmed by testing.
  • The preferred antibiotic regimens for treatment of acute GABHS pharyngitis if the patient is not allergic to penicillin are 1 of:
    • penicillin V (Strong recommendation)
      • 250 mg orally 2-3 times daily for 10 days in children
      • 500 mg twice daily or 250 mg 4 times daily for 10 days in adults and adolescents
    • benzathine penicillin G 1.2 million units (600,000 units if weight < 27 kg [60 lbs]) intramuscularly once (preferred therapy for patients unlikely to complete 10-day course of oral therapy) (Strong recommendation)
    • amoxicillin 50 mg/kg (up to 1,000 mg dose) orally once daily or 25 mg/kg (up to 500 mg dose) twice daily for 10 days (Strong recommendation)
  • The preferred antibiotic regimens for treatment of acute GABHS pharyngitis if the patient is allergic to penicillin are 1 of:
    • cephalexin 20 mg/kg (up to 500 mg/dose) orally twice daily for 10 days, but avoid if immediate-type hypersensitivity to penicillin (Strong recommendation)
    • cefadroxil 30 mg/kg (up to 1,000 mg) orally once daily for 10 days, but avoid if immediate-type hypersensitivity to penicillin (Strong recommendation)
    • clindamycin 7 mg/kg (up to 300 mg/dose) orally 3 times daily for 10 days (Strong recommendation)
    • azithromycin 12 mg/kg (up to 500 mg) orally once daily for 5 days, but check for local group A Streptococcus resistance (Strong recommendation)
    • clarithromycin 7.5 mg/kg (up to 250 mg/dose) orally twice daily for 10 days, but check for local group A Streptococcus resistance (Strong recommendation)
  • Other options for cephalosporins include (all oral):
    • cefuroxime 10 mg/kg (up to 250 mg/dose) twice daily for 10 days
    • cefpodoxime 5 mg/kg (up to 100 mg/dose) twice daily for 5 to 10 days
    • cefdinir 7 mg/kg (up to 300 mg/dose) twice daily for 5 to 10 days, or 14 mg/kg (up to 600 mg/dose) once daily for 10 days.
  • See also Antibiotics for Streptococcal Pharyngitis.
• Use antibiotics to treat more serious infections if identified, such as peritonsillar abscess, parapharyngeal abscess, epiglottitis, and Lemierre syndrome.
• Do not offer a tonsillectomy to reduce the frequency of group A streptococcal infections in most patients (Strong recommendation). Consider a tonsillectomy for patients with ≥ 7 episodes in 1 year, ≥ 5 episodes/year for 2 years, or ≥ 3 episodes/year for 3 years (Weak recommendation).
• Do not perform retesting after treatment unless there are recurrent symptoms or a high risk of acute rheumatic fever (Strong recommendation).
• Do not offer prophylactic treatment of exposed siblings (Strong recommendation).