What is the recommended treatment for streptococcal (strep) infections?

Treatment of Streptococcal Pharyngitis

Penicillin or amoxicillin for 10 days is the first-line treatment for confirmed Group A streptococcal pharyngitis due to proven efficacy, narrow spectrum, safety profile, and low cost. 1, 2

First-Line Antibiotic Regimens for Non-Allergic Patients

Penicillin V (oral): 1, 2

• Children: 250 mg two or three times daily for 10 days
• Adolescents and adults: 250 mg four times daily OR 500 mg twice daily for 10 days
• Twice-daily dosing is equally effective as more frequent dosing and may improve adherence 3

Amoxicillin (oral): 1, 2

• 50 mg/kg once daily (maximum 1,000 mg) for 10 days
• Alternative: 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days
• Once-daily amoxicillin is as effective as three-times-daily penicillin V and offers better palatability for children 4, 3

Benzathine Penicillin G (intramuscular): 1, 2

• Single dose: 600,000 units for patients <60 lb (27 kg); 1,200,000 units for patients ≥60 lb
• Reserved for patients unlikely to complete oral therapy due to compliance concerns 2

Treatment for Penicillin-Allergic Patients

For non-anaphylactic penicillin allergy (10-day courses): 1

• Cephalexin: 20 mg/kg per dose twice daily (maximum 500 mg per dose) 1, 5
• Cefadroxil: 30 mg/kg once daily (maximum 1 g) 1

For anaphylactic penicillin allergy: 1

• Clindamycin: 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days 1, 5
• Clarithromycin: 7.5 mg/kg per dose twice daily (maximum 250 mg per dose) for 10 days 1
• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 5

Critical caveat: Macrolide resistance (azithromycin, clarithromycin) varies significantly by geographic region, and susceptibility testing should be performed when these agents are used 6, 7. The FDA label explicitly states that azithromycin should not be relied upon to prevent rheumatic fever due to resistance concerns 6.

Why 10 Days Matters

The standard 10-day course is necessary to achieve maximal pharyngeal eradication of Group A streptococcus and prevent rheumatic fever 1, 2, 8. Meta-analysis demonstrates that short-course penicillin (≤5 days) is significantly less effective for both clinical cure and bacterial eradication compared to 10-day courses 9. While short-course cephalosporins show comparable efficacy, their broader spectrum raises antimicrobial stewardship concerns 9.

Adjunctive Symptomatic Treatment

Analgesics/antipyretics: 1, 2, 10

• Acetaminophen or NSAIDs for moderate to severe symptoms or high fever
• Never use aspirin in children due to Reye syndrome risk 1, 2, 10

Corticosteroids are NOT recommended for routine streptococcal pharyngitis treatment 1, 10

Diagnostic Confirmation Before Treatment

Testing is essential to avoid unnecessary antibiotic use: 2, 10

• Positive rapid antigen detection test (RADT) is diagnostic and sufficient to initiate treatment 2, 5
• Backup throat culture is recommended for children and adolescents with negative RADT 2
• Do NOT test or treat if clinical features strongly suggest viral etiology: cough, rhinorrhea, hoarseness, oral ulcers, conjunctivitis 1, 10

Clinical features favoring streptococcal infection include: sudden onset sore throat, fever, tonsillopharyngeal exudates, tender anterior cervical lymphadenopathy, age 5-15 years, absence of cough 1, 2, 7

Management of Recurrent Pharyngitis and Chronic Carriers

Patients with recurrent positive tests may be chronic carriers experiencing intercurrent viral infections rather than true streptococcal pharyngitis 1, 5. Chronic carriers are at very low risk for complications and do not routinely require eradication therapy 5.

Consider carrier eradication treatment only in special circumstances: 1, 5

• Community outbreak of rheumatic fever or invasive GAS infection
• Personal or family history of rheumatic fever
• Closed community outbreak
• Excessive patient/family anxiety about GAS

Eradication regimens: 5

• Clindamycin 7 mg/kg three times daily for 10 days
• Amoxicillin-clavulanate for 10 days
• Penicillin V plus rifampin

Common Pitfalls to Avoid

Do NOT prescribe antibiotics for likely viral pharyngitis (with cough, rhinorrhea, hoarseness, oral ulcers) as this provides no benefit and drives antibiotic resistance 1, 10. Over 60% of adults with sore throat receive antibiotics despite only 10% having streptococcal infection 7.

Do NOT use once-daily penicillin V as it shows 12 percentage points lower cure rate compared to more frequent dosing 3. Once-daily amoxicillin, however, is effective 4, 3.

Do NOT perform routine post-treatment cultures in asymptomatic patients 1, 2. Follow-up testing is only indicated in special circumstances such as personal history of rheumatic fever 1.

Do NOT test or treat asymptomatic household contacts routinely, as this is not warranted given the self-limited nature of GAS pharyngitis and limited efficacy of prophylaxis 1.