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 or three times daily for children 1, 2
Oral amoxicillin for 10 days is an equally effective alternative, particularly for young children due to better taste acceptance, with a dosage of 50 mg/kg once daily (maximum 1,000 mg) or 25 mg/kg twice daily (maximum 500 mg) 1, 2
Once-daily amoxicillin (750 mg or 1,000 mg based on weight) has been shown to be non-inferior to twice-daily dosing and may improve compliance 3, 2
Intramuscular benzathine penicillin G as a single dose is recommended for patients unlikely to complete a full 10-day oral course, with dosage of 600,000 units for patients <60 lb (27 kg) and 1,200,000 units for patients ≥60 lb 1, 2
Alternative Treatment Options 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 4, 2
For patients with anaphylactic penicillin allergy, clindamycin (7 mg/kg per dose three times daily, maximum 300 mg per dose) for 10 days is recommended 4, 2
Macrolides such as clarithromycin (7.5 mg/kg per dose twice daily, maximum 250 mg per dose) for 10 days or azithromycin (12 mg/kg once daily, maximum 500 mg) for 5 days can be used in patients with severe penicillin allergy 4, 5
Treatment Duration Considerations
The standard 10-day course of antibiotics is recommended to ensure complete eradication of the organism and prevent rheumatic fever 1, 2
Some studies suggest that shorter courses (5-7 days) of antibiotics may be effective, but these are not yet widely recommended in guidelines 6, 2
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 1, 2
A positive rapid antigen detection test (RADT) is diagnostic for group A streptococcal pharyngitis and does not require backup culture 1, 2
A backup throat culture is recommended for children and adolescents with negative RADT results 1, 2
Management of Recurrent Cases
For recurrent pharyngitis, retreatment with the same agent used initially is recommended 1, 2
If compliance with oral therapy is questionable, intramuscular benzathine penicillin G should be considered 1, 2
For chronic carriers with viral infections, clindamycin or amoxicillin/clavulanate may be effective 4, 2
Common Pitfalls to Avoid
Overtreatment of likely viral pharyngitis (with cough, rhinorrhea, hoarseness, oral ulcers) should be avoided 1, 2
Routine post-treatment throat cultures for asymptomatic patients are not recommended 1, 2
Using macrolides in areas with high resistance rates should be avoided, as resistance to these antibiotics varies geographically 4, 5
Failure to complete the full course of antibiotics can lead to treatment failure and increased risk of complications 7, 2
Penicillin treatment failure rates have increased over time (now approximately 30%), often due to poor compliance with the 10-day regimen 7, 2