What is the recommended treatment for Streptococcal (Strep) pharyngitis?

Treatment of Streptococcal Pharyngitis

Penicillin or amoxicillin for 10 days remains the first-line treatment for streptococcal pharyngitis due to proven efficacy, no documented resistance, narrow spectrum, safety, and low cost. 1, 2

First-Line Antibiotic Therapy

Standard Treatment for Non-Allergic Patients

• Penicillin V or amoxicillin for a full 10-day course is the drug of choice, with no documented penicillin resistance in Group A Streptococcus anywhere in the world 1, 2
• Penicillin V dosing: 250 mg orally twice daily for 10 days in children; 250-500 mg twice to three times daily for 10 days in adults 1
• Amoxicillin is equally effective and often preferred due to better palatability and twice-daily dosing 1
• Intramuscular benzathine penicillin G is preferred when compliance with oral therapy is questionable, as it ensures complete treatment and prevents rheumatic fever 1, 3

Critical Treatment Duration

• A full 10-day course is essential to achieve maximal pharyngeal eradication of Group A Streptococcus and prevent acute rheumatic fever 1, 2, 3
• Shortening the course by even a few days results in appreciable increases in treatment failure rates and risk of complications 1, 2
• The primary goal is not just symptomatic improvement but prevention of acute rheumatic fever, which requires adequate bacterial eradication 1

Treatment for Penicillin-Allergic Patients

Non-Immediate (Non-Anaphylactic) Penicillin Allergy

• First-generation cephalosporins are the preferred first-line alternatives, with strong, high-quality evidence supporting their efficacy 1, 2
• Cephalexin: 20 mg/kg per dose twice daily (maximum 500 mg/dose) for 10 days in children; 500 mg twice daily for 10 days in adults 2
• Cefadroxil: 30 mg/kg once daily (maximum 1 gram) for 10 days 2
• Cross-reactivity risk is only 0.1% in patients with non-severe, delayed penicillin reactions 2
• Narrow-spectrum first-generation cephalosporins are strongly preferred over broad-spectrum agents (cefdinir, cefixime, cefpodoxime) due to lower cost and reduced selection for antibiotic-resistant flora 1

Immediate/Anaphylactic Penicillin Allergy

• All beta-lactam antibiotics must be avoided due to up to 10% cross-reactivity risk in patients with immediate hypersensitivity reactions (anaphylaxis, angioedema, respiratory distress, or urticaria within 1 hour) 1, 2
• Clindamycin is the preferred alternative with strong, moderate-quality evidence: 7 mg/kg per dose three times daily (maximum 300 mg/dose) for 10 days 1, 2
• Clindamycin resistance is approximately 1% in the United States, making it highly reliable 1, 2
• Clindamycin demonstrates superior efficacy in eradicating streptococci, even in chronic carriers and treatment failures 1, 2

Macrolide Alternatives (Less Preferred)

• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days—the only antibiotic requiring just 5 days due to prolonged tissue half-life 1, 2, 4
• Clarithromycin: 7.5 mg/kg per dose twice daily (maximum 250 mg/dose) for 10 days 1, 2
• Erythromycin: 20-40 mg/kg/day divided 2-3 times daily (maximum 1 gram/day) for 10 days—less preferred due to high gastrointestinal side effects 1, 2
• Critical limitation: Macrolide resistance is 5-8% in the United States and varies geographically, with some areas experiencing much higher rates 1, 2
• Important caveat: Data establishing efficacy of azithromycin in preventing rheumatic fever are not available, unlike penicillin 4

Common Pitfalls to Avoid

• Do not prescribe shorter courses than 10 days (except azithromycin's 5-day regimen), as this dramatically increases treatment failure and rheumatic fever risk 1, 2
• Do not use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to the 10% cross-reactivity risk 1, 2
• Do not use azithromycin or macrolides as first-line therapy when penicillin can be used—reserve for documented penicillin allergy 1, 2
• Do not use broad-spectrum cephalosporins when narrow-spectrum first-generation agents are appropriate, as they are more expensive and select for resistant flora 1
• Do not use trimethoprim-sulfamethoxazole (Bactrim) for strep throat—it is ineffective due to high resistance rates and cannot prevent rheumatic fever 2

Adjunctive Symptomatic Therapy

• Acetaminophen or NSAIDs (such as ibuprofen) should be considered for moderate to severe symptoms or high fever, with strong, high-quality evidence for reducing pain and inflammation 1, 2
• Aspirin must be avoided in children due to risk of Reye syndrome 1, 2
• Corticosteroids are not recommended as adjunctive therapy—they provide only minimal symptom reduction (approximately 5 hours) and carry potential adverse effects 1, 2

Post-Treatment Considerations

• Routine follow-up throat cultures or rapid antigen tests are not recommended for asymptomatic patients who have completed therapy 2, 3
• Patients are no longer contagious after 24 hours of appropriate antibiotic therapy 3
• Clinical improvement typically occurs within 24-48 hours of starting antibiotics 3
• Follow-up testing should only be considered in special circumstances, such as patients with a history of rheumatic fever or in outbreak situations 3