What is the recommended treatment for pharyngitis?

Treatment of Pharyngitis

Penicillin or amoxicillin for 10 days is the definitive first-line treatment for Group A streptococcal (GAS) pharyngitis, based on proven efficacy, narrow spectrum, safety profile, and the absence of documented resistance. 1

Diagnostic Approach Before Treatment

• Test patients with 2 or more Centor criteria (fever history, tonsillar exudates, absence of cough, tender anterior cervical lymphadenopathy) using rapid antigen detection test (RADT) or throat culture 1
• Do not test or treat patients with 0-1 Centor criteria as they are unlikely to have GAS infection 2
• Children under 3 years generally do not require testing unless they have specific risk factors like an older sibling with GAS infection 1

First-Line Antibiotic Therapy

For Penicillin-Tolerant Patients

Penicillin V remains the gold standard due to its narrow spectrum, proven efficacy, safety, and low cost 1:

• Adults: 500 mg orally twice daily for 10 days 1
• Children: 250 mg twice daily or 250 mg three times daily for 10 days 1

Amoxicillin is equally effective and often preferred for palatability, especially in children 1:

• Adults and children ≥40 kg: 500 mg twice daily for 10 days 1, 3
• Children <40 kg: 25 mg/kg/day divided twice daily (or 50 mg/kg once daily, maximum 1000 mg) for 10 days 1, 3

Intramuscular benzathine penicillin G is preferred when adherence is questionable 1:

• Children <27 kg: 600,000 units as single dose 1
• Children ≥27 kg and adults: 1,200,000 units as single dose 1

For Penicillin-Allergic Patients

The type of allergic reaction determines the alternative antibiotic choice 1, 4:

Non-Immediate/Non-Anaphylactic Allergy

First-generation cephalosporins are the preferred alternatives with strong, high-quality evidence 1, 4:

• Cephalexin: 20 mg/kg/dose twice daily (maximum 500 mg/dose) for 10 days 1, 4
• Cefadroxil: 30 mg/kg once daily (maximum 1 gram) for 10 days 1, 4

Immediate/Anaphylactic Allergy

Avoid all beta-lactams including cephalosporins due to up to 10% cross-reactivity risk 1, 4

Clindamycin is the preferred choice with approximately 1% resistance in the United States 1, 4:

• Dosing: 7 mg/kg/dose three times daily (maximum 300 mg/dose) for 10 days 1, 4

Macrolides are acceptable alternatives but have higher resistance rates (5-8% in the US) 1, 4:

• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days only 1, 4
• Clarithromycin: 7.5 mg/kg/dose twice daily (maximum 250 mg/dose) for 10 days 1, 4

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, 3. Azithromycin requires only 5 days due to its prolonged tissue half-life 1, 4.

Treatment can be initiated up to 9 days after symptom onset and still prevent acute rheumatic fever 4.

Adjunctive Symptomatic Therapy

NSAIDs are more effective than acetaminophen for fever and pain control 5:

• Consider acetaminophen or NSAIDs (ibuprofen) for moderate to severe symptoms 1, 4
• Avoid aspirin in children due to Reye syndrome risk 1, 4

Medicated throat lozenges every 2 hours are effective for symptom relief 5

Corticosteroids are not recommended as they provide only minimal benefit 1, 5

Special Clinical Situations

Recurrent Pharyngitis

Distinguish between true recurrent infections versus chronic carrier with viral infections 1. For documented recurrent GAS infections with treatment failures 1:

• Clindamycin: 20-30 mg/kg/day for children or 600 mg/day in 2-4 divided doses for adults for 10 days 1
• Amoxicillin-clavulanate: 40 mg/kg/day in 3 divided doses for 10 days (maximum 750 mg amoxicillin/day) 1
• Benzathine penicillin G with consideration of adding rifampin 10 mg/kg twice daily for 4 days (maximum 300 mg twice daily) 1

Pregnancy

Penicillin and amoxicillin remain first-line with proven safety 6. For penicillin-allergic pregnant patients, use cephalexin/cefadroxil for non-anaphylactic allergy or clindamycin for anaphylactic allergy 6. Avoid rifampin in pregnancy 6.

Concurrent Infectious Mononucleosis

Avoid amoxicillin and ampicillin if infectious mononucleosis is suspected, as they cause a characteristic rash 6, 7. Use first-generation cephalosporin or macrolide instead if GAS treatment is needed 7.

Common Pitfalls to Avoid

• Do not prescribe shorter courses than recommended (except azithromycin's 5-day regimen) as this increases treatment failure and rheumatic fever risk 1, 4
• Do not use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to 10% cross-reactivity 1, 4
• Do not use tetracyclines, sulfonamides, trimethoprim-sulfamethoxazole, or older fluoroquinolones as they are ineffective against GAS 1
• Do not perform routine follow-up cultures in asymptomatic patients who completed therapy 1, 4
• Do not test or treat asymptomatic household contacts routinely 1
• Do not use broad-spectrum cephalosporins when narrow-spectrum agents are appropriate, as they increase cost and select for resistant flora 1
• Check local macrolide resistance patterns before prescribing azithromycin or clarithromycin, as resistance varies geographically 4