What is the recommended treatment for streptococcal pharyngitis?

Treatment of Streptococcal Pharyngitis

Penicillin or amoxicillin for 10 days is the first-line treatment for confirmed group A streptococcal pharyngitis, with penicillin V (250 mg twice daily for children, 500 mg twice daily for adults) or amoxicillin (50 mg/kg once daily, maximum 1000 mg) being equally effective and preferred due to their narrow spectrum, proven efficacy in preventing rheumatic fever, and low cost. 1, 2

Diagnostic Approach Before Treatment

• Testing is essential before prescribing antibiotics—do not treat based on clinical suspicion alone 2, 3
• Use rapid antigen detection test (RADT) for patients with clinical features suggesting streptococcal infection: sudden onset sore throat, fever, tonsillopharyngeal exudates, tender anterior cervical lymphadenopathy, and absence of cough 1, 2
• A positive RADT is diagnostic and requires no backup culture 2
• For children and adolescents with negative RADT, perform backup throat culture before withholding antibiotics 2, 3
• Do not test or treat if viral features are present: cough, rhinorrhea, hoarseness, conjunctivitis, or oral ulcers strongly suggest viral etiology 1, 4

First-Line Antibiotic Regimens (Non-Allergic Patients)

Oral Penicillin V

• Children: 250 mg two or three times daily for 10 days 1, 2
• Adolescents and adults: 250 mg four times daily OR 500 mg twice daily for 10 days 1, 2
• The 10-day duration is critical for complete bacterial eradication and rheumatic fever prevention 2, 5

Oral Amoxicillin (Equally Effective Alternative)

• Preferred dosing: 50 mg/kg once daily (maximum 1000 mg) for 10 days 1, 2
• Alternative: 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1, 2
• Once-daily dosing improves compliance with equivalent efficacy to multiple daily dosing 6, 7

Intramuscular Benzathine Penicillin G

• Use when: Compliance with oral therapy is questionable or in populations with high rheumatic fever risk 2, 8
• Dosing: 600,000 units for patients <60 lb (27 kg); 1,200,000 units for patients ≥60 lb 1, 2
• Single dose ensures complete treatment but is more painful 8

Treatment for Penicillin-Allergic Patients

Non-Anaphylactic Penicillin Allergy

• First-generation cephalosporins are preferred 9, 3
• Cephalexin: 20 mg/kg per dose twice daily (maximum 500 mg per dose) for 10 days 1, 9
• Cefadroxil: 30 mg/kg once daily (maximum 1 g) for 10 days 1, 9

Anaphylactic Penicillin Allergy

• Clindamycin: 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days 1, 9
• Clarithromycin: 7.5 mg/kg per dose twice daily (maximum 250 mg per dose) for 10 days 1, 9
• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 9

Critical caveat: Macrolide resistance (azithromycin, clarithromycin) is significant and geographically variable in the United States—susceptibility testing should be performed when using these agents 10, 3. Azithromycin does not have established efficacy data for preventing rheumatic fever 10.

Adjunctive Symptomatic Treatment

• Acetaminophen or NSAIDs for moderate to severe pain or high fever 2, 4
• Never use aspirin in children due to Reye syndrome risk 1, 2, 4
• Corticosteroids are not recommended—they provide minimal benefit (approximately 5 hours symptom reduction) with potential adverse effects 4

Common Pitfalls to Avoid

• Do not prescribe antibiotics for viral pharyngitis (patients with cough, rhinorrhea, hoarseness)—this accounts for 90% of adult sore throats and contributes to antibiotic resistance 4, 3
• Do not use short-course penicillin (<10 days)—it is significantly less effective for bacterial eradication and clinical cure compared to 10-day courses 5
• Do not routinely perform post-treatment cultures in asymptomatic patients 2
• Do not test or treat household contacts unless they are symptomatic 1
• Avoid macrolides as first-line even in allergic patients if cephalosporins are tolerated, due to increasing resistance rates 9, 3

When to Reevaluate

• Patients with worsening symptoms after starting appropriate antibiotics or symptoms persisting 5 days after treatment initiation require reevaluation 3
• Consider treatment failure, non-compliance, resistant organism, or alternative diagnosis 3

The evidence strongly supports penicillin or amoxicillin as superior first-line agents based on decades of proven efficacy, prevention of rheumatic fever, narrow spectrum minimizing resistance, and cost-effectiveness 1, 2, 8. Shorter courses with newer antibiotics may show equivalent clinical cure rates but should not replace 10-day penicillin/amoxicillin as the standard of care given concerns about antimicrobial stewardship 5.