Streptococcal pharyngitis

Background

  • Peak in 5-15yr old
  • Rare in <2yr of age
  • Accounts for only 15-30% of pharyngitis
  • Caused by S. pyogenes (Group A strep)

Clinical Features

culture positive strep pharyngitis with typical tonsillar exudate

Should NOT have a rash; if have scarlatiniform rash consider scarlet fever

Differential Diagnosis


Acute Sore Throat

Bacterial infections


Viral infections


Noninfectious


Other

Oral rashes and lesions

Evaluation

Modified Centor Criteria[2]

One point is given for each of the criteria:[2]

  1. Absence of a cough
  2. Swollen and tender cervical lymph nodes
  3. Temperature >38.0 °C (100.4 °F)
  4. Tonsillar exudate or swelling
  5. Age less than 15^
    • Subtract a point if age >44
Modified Centor score
Points Probability of Streptococcal pharyngitis
1 or fewer <10%
2 11–17%
3 28–35%
4 or 5 52%

Management

Antibiotics

Treatment can be delayed for up to 9 days and still prevent major sequelae

Penicillin Options:

Penicillin allergic (mild):

  • Cephalexin 20 mg per kg PO BID (maximum 500 mg per dose) x 10 days[7]
  • Cefadroxil 30 mg per kg PO QD (maximum 1 g daily) x 10 days[8]

Penicillin allergic (anaphylaxis):[3]

  • Clindamycin 7 mg/kg/dose TID (maximum = 300 mg/dose) x 10 days[9]
  • Azithromycin 12 mg/kg PO once (maximum = 500 mg), then 6 mg/kg (max=250 mg) once daily for the next 4 days[10]
  • Clarithromycin 7.5 mg/kg/dose PO BID (maximum = 250 mg/dose) x 10 days[11]

Steroids

Disposition

  • Discharge

Complications

See Also

References

  1. Melio, Frantz, and Laurel Berge. “Upper Respiratory Tract Infection.” In Rosen’s Emergency Medicine., 8th ed. Vol. 1, n.d.
  2. 2.0 2.1 Choby BA (March 2009). "Diagnosis and treatment of streptococcal pharyngitis". Am Fam Physician 79 (5): 383–90. PMID 19275067.
  3. 3.0 3.1 3.2 Shulman, et al. Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of America. Clinical Infectious Diseases 2012;55(10):1279–82
  4. CDC Website, accessed 2026-28-01. https://www.cdc.gov/group-a-strep/hcp/clinical-guidance/strep-throat.html
  5. CDC Website, accessed 2026-28-01. https://www.cdc.gov/group-a-strep/hcp/clinical-guidance/strep-throat.html
  6. CDC Website, accessed 2026-28-01. https://www.cdc.gov/group-a-strep/hcp/clinical-guidance/strep-throat.html
  7. CDC Website, accessed 2026-28-01. https://www.cdc.gov/group-a-strep/hcp/clinical-guidance/strep-throat.html
  8. CDC Website, accessed 2026-28-01. https://www.cdc.gov/group-a-strep/hcp/clinical-guidance/strep-throat.html
  9. CDC Website, accessed 2026-28-01. https://www.cdc.gov/group-a-strep/hcp/clinical-guidance/strep-throat.html
  10. CDC Website, accessed 2026-28-01. https://www.cdc.gov/group-a-strep/hcp/clinical-guidance/strep-throat.html
  11. CDC Website, accessed 2026-28-01. https://www.cdc.gov/group-a-strep/hcp/clinical-guidance/strep-throat.html
  12. Hayward G, Thompson MJ, Perera R, Glasziou PP, Del Mar CB, Heneghan CJ. Corticosteroids as standalone or add-on treatment for sore throat. Cochrane Database Syst Rev. 2012 Oct 17;10:CD008268. PMID: 23076943.