What is the recommended treatment for acute pharyngitis?

Treatment of Acute Pharyngitis

For confirmed Group A Streptococcal (GAS) pharyngitis, penicillin or amoxicillin for 10 days is the recommended first-line treatment due to proven efficacy, narrow spectrum, lack of resistance, and low cost. 1

Diagnostic Approach

• Do not test or treat patients with clear viral features including cough, rhinorrhea, hoarseness, or oral ulcers, as these strongly suggest viral etiology 1
• Confirm GAS pharyngitis with rapid antigen detection test (RADT) or throat culture before initiating antibiotics 1
• Do not routinely test children under 3 years old unless specific risk factors exist (e.g., older sibling with GAS infection), as acute rheumatic fever is rare in this age group 1
• A positive RADT is sufficient for diagnosis and does not require backup culture 2

First-Line Antibiotic Treatment for Non-Allergic Patients

Penicillin remains the treatment of choice because penicillin-resistant GAS has never been documented 1

Dosing Regimens:

• Penicillin V (oral): 250 mg twice daily for 10 days 1
• Amoxicillin (oral): 50 mg/kg once daily (maximum 1000 mg) OR 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1
• Benzathine penicillin G (intramuscular): <27 kg: 600,000 units; ≥27 kg: 1,200,000 units as single dose 1

Amoxicillin is often preferred over penicillin V in young children due to better palatability and once-daily dosing option that enhances adherence 1

Treatment for Penicillin-Allergic Patients

Non-Anaphylactic Penicillin Allergy:

First-generation cephalosporins are the preferred alternative 3, 2

• Cephalexin: 20 mg/kg per dose twice daily (maximum 500 mg/dose) for 10 days 1, 3
• Cefadroxil: 30 mg/kg once daily (maximum 1 g) for 10 days 1, 3

Immediate/Anaphylactic Penicillin Allergy:

Avoid all beta-lactams including cephalosporins due to up to 10% cross-reactivity risk 1, 3

Alternative options include:

• Clindamycin (preferred): 7 mg/kg per dose three times daily (maximum 300 mg/dose) for 10 days 1, 3
• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 3
• Clarithromycin: 7.5 mg/kg per dose twice daily (maximum 250 mg/dose) for 10 days 1, 3

Clindamycin demonstrates high efficacy even in chronic carriers and has approximately 1% resistance among GAS isolates in the United States 3

Critical Treatment Duration Requirements

A full 10-day course is mandatory for all antibiotics except azithromycin to achieve maximal pharyngeal eradication and prevent acute rheumatic fever 1

• Azithromycin requires only 5 days due to its prolonged tissue half-life 1, 3
• Shortening the course by even a few days results in appreciably higher treatment failure rates 4

Expected Clinical Response

Patients should show clinical improvement within 24-48 hours of starting antibiotics 1, 4

• Fever should begin declining within 48 hours 4
• Sore throat, irritability, and other symptoms should lessen within 48 hours 4
• Patients become non-contagious after 24 hours of antibiotic therapy 4
• If no improvement occurs within 48-72 hours, reevaluate for alternative diagnosis, concomitant viral infection, or consider non-compliance 4

Adjunctive Therapy

• Use acetaminophen or NSAIDs for moderate to severe symptoms or high fever 1
• Avoid aspirin in children due to risk of Reye syndrome 1
• Do not use corticosteroids as adjunctive therapy 1

Important Considerations and Pitfalls

Macrolide Resistance:

• Be aware of local resistance patterns before prescribing azithromycin or clarithromycin, as macrolide resistance varies geographically (approximately 5-8% in the United States) 3, 2
• Approximately 1% of azithromycin-susceptible S. pyogenes isolates become resistant following therapy 5

Recurrent Pharyngitis:

• Distinguish between true recurrent infections versus chronic GAS carrier experiencing viral infections 1, 2
• Chronic carriers do not require antimicrobial therapy as they are unlikely to spread infection or develop complications 1, 3

Follow-Up Testing:

• Do not perform routine post-treatment throat cultures or RADT in asymptomatic patients who completed therapy 1
• Follow-up testing may be considered only in special circumstances (e.g., history of rheumatic fever) 1

Household Contacts:

• Do not routinely test or treat asymptomatic household contacts, as antibiotic prophylaxis has limited efficacy and GAS pharyngitis is self-limited 1

Common Errors to Avoid:

• Discontinuing antibiotics when symptoms improve before completing the full course 4
• Assuming all penicillin-allergic patients cannot receive cephalosporins (only those with immediate/anaphylactic reactions should avoid them) 3
• Treating viral pharyngitis with antibiotics based on clinical features alone without confirmatory testing 1
• Using trimethoprim-sulfamethoxazole for GAS pharyngitis, which has high resistance rates and is not recommended 3