Treatment of Streptococcal Pharyngitis
Penicillin or amoxicillin for 10 days is the first-line treatment for streptococcal pharyngitis, as recommended by the Infectious Diseases Society of America (IDSA) and the American Academy of Pediatrics. 1
First-Line Treatment Options
Adults:
- Penicillin V: 500 mg orally 2-3 times daily for 10 days 1
- Amoxicillin: 1000 mg once daily or 500 mg twice daily for 10 days 1
Children:
- Penicillin V: 250 mg orally 2-3 times daily for 10 days 1
- Amoxicillin: 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1
Alternative Treatment for Penicillin-Allergic Patients
Non-Anaphylactic Penicillin Allergy:
- First-generation cephalosporins for 10 days 1
Anaphylactic Penicillin Allergy:
- Clindamycin: 300-450 mg orally three times daily for 10 days 1
- Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 2
- Clarithromycin: 10 days 1
Caution: Significant resistance to azithromycin and clarithromycin exists in some parts of the United States 1, 3
Diagnosis and Testing Algorithm
Assess using Centor Criteria:
- Tonsillar exudates
- Tender anterior cervical lymph nodes
- Lack of cough
- Fever 1
Testing recommendations:
- 0-2 Centor criteria: No testing needed (unlikely to be Group A Strep)
- 3-4 Centor criteria: Test with Rapid Antigen Detection Test (RADT) and/or throat culture 1
After negative RADT:
Treatment Considerations
Duration Importance
- The full 10-day course is critical for:
- Preventing acute rheumatic fever
- Preventing acute glomerulonephritis
- Reducing risk of relapse 1
Treatment Failures
- Penicillin treatment failures occur in 5-35% of cases 1
- Potential causes include:
- Beta-lactamase-producing bacteria "shielding" streptococci
- Poor compliance with 10-day regimen
- Reexposure to infected individuals 4
Return to School/Work
- Patients should complete at least 24 hours of antibiotics before returning to school or work to reduce transmission risk 1
Supportive Care
- Pain and fever management: Acetaminophen or NSAIDs (avoid aspirin in children) 1
- Comfort measures: Cold liquids, ice chips, gargling with cold water 1
Special Considerations
- Fluoroquinolones (including moxifloxacin) are not recommended due to unnecessarily broad spectrum and concerns about resistance development 1
- Tonsillectomy is rarely recommended as prevention and should be considered only after multiple documented episodes (7 episodes in 1 year, 5 episodes in each of 2 consecutive years, or 3 episodes in each of 3 consecutive years) 3
Follow-up
- Patients with worsening symptoms after antibiotic initiation or symptoms persisting for 5 days after starting treatment should be reevaluated 3