Treatment of Streptococcal Pharyngitis
Penicillin or amoxicillin is the first-line treatment for streptococcal pharyngitis due to their proven efficacy, safety, narrow spectrum of activity, and low cost. 1, 2
First-Line Treatment Options
- For patients without penicillin allergy, oral penicillin V for 10 days is recommended at a dosage of 250 mg four times daily or 500 mg twice daily for adolescents and adults, and 250 mg two to three times daily for children 1, 2
- Amoxicillin is an equally effective alternative, administered as 50 mg/kg once daily (maximum 1,000 mg) or 25 mg/kg twice daily (maximum 500 mg) for 10 days 2, 3
- Once-daily amoxicillin (50 mg/kg, maximum 1,000 mg) for 10 days has been shown to be as effective as multiple daily doses of penicillin V, potentially improving adherence 4, 3
- Intramuscular benzathine penicillin G (single dose) is recommended for patients unlikely to complete a full 10-day oral course, with a dosage of 600,000 units for patients < 60 lb and 1,200,000 units for patients ≥ 60 lb 2
Treatment for Penicillin-Allergic Patients
- For patients with non-anaphylactic penicillin allergy, first-generation cephalosporins such as cephalexin (20 mg/kg per dose twice daily, maximum 500 mg per dose) for 10 days are recommended 1, 5
- For patients with anaphylactic penicillin sensitivity, the following options are recommended for 10 days:
Important Clinical Considerations
- A standard 10-day course of antibiotics is essential to ensure complete eradication of the organism and prevent rheumatic fever 1, 2
- Short-course penicillin therapy (≤5 days) is less effective for clinical cure and bacterial eradication compared to the standard 10-day course 7
- Macrolides (azithromycin, clarithromycin) should be used cautiously due to variable geographic resistance patterns 5, 6
- Penicillin resistance in Group A Streptococcus has never been documented, making it a reliable first-line option 1
Diagnostic Approach
- Testing is recommended for patients with clinical features suggesting streptococcal infection, including sudden onset of sore throat, fever, headache, tonsillopharyngeal inflammation or exudates, and tender anterior cervical lymphadenopathy 2
- A positive rapid antigen detection test (RADT) is diagnostic for group A streptococcal pharyngitis 2
- For children and adolescents with negative RADT results, a backup throat culture is recommended 2
Adjunctive Therapy
- Acetaminophen or NSAIDs are recommended for moderate to severe symptoms or high fever 2, 5
- Aspirin should be avoided in children due to the risk of Reye syndrome 2, 5
Common Pitfalls to Avoid
- Overtreatment of viral pharyngitis with antibiotics should be avoided; clinical features suggesting viral etiology include cough, rhinorrhea, hoarseness, and oral ulcers 8
- Routine post-treatment throat cultures for asymptomatic patients are not recommended 1, 2
- Using macrolides in areas with high resistance rates should be avoided 5, 6
- Failing to complete the full 10-day course of antibiotics may lead to treatment failure and increased risk of rheumatic fever 1, 2