What is the recommended treatment for pharyngitis?

Treatment of Pharyngitis

Diagnostic Testing Before Treatment

Testing for Group A Streptococcal (GAS) pharyngitis is mandatory before initiating antibiotics, as clinical features alone cannot reliably distinguish bacterial from viral causes. 1, 2

• Perform rapid antigen detection test (RADT) or throat culture in patients with clinical features suggesting possible GAS infection 1, 3
• Do NOT test patients with clear viral features (cough, rhinorrhea, hoarseness, oral ulcers) as these strongly suggest non-streptococcal etiology 1
• Children under 3 years generally do not require testing unless specific risk factors exist (e.g., older sibling with GAS infection) 1
• Positive RADT confirms diagnosis and justifies antibiotic treatment due to high specificity (>95%) 1
• Negative RADT in children and adolescents should be backed up by throat culture due to lower sensitivity 1
• Adults with negative RADT do not routinely need backup culture given low incidence of GAS and minimal rheumatic fever risk 1

First-Line Antibiotic Treatment

Penicillin or amoxicillin for 10 days is the definitive first-line treatment for confirmed GAS pharyngitis, based on proven efficacy in preventing rheumatic fever, narrow spectrum, complete absence of resistance, safety profile, and low cost. 1, 2, 3

Penicillin Regimens (Non-Allergic Patients)

• Oral Penicillin V: 500 mg twice daily for adults OR 250 mg twice daily (or three times daily) for children, for 10 days 1, 3
• Amoxicillin: 500 mg twice daily for adults/children ≥40 kg OR 25 mg/kg twice daily (maximum 500 mg per dose) for children <40 kg, for 10 days 3, 4
• Alternative amoxicillin dosing: 50 mg/kg once daily (maximum 1000 mg) for 10 days may improve adherence, particularly in young children due to better palatability 2, 3
• Intramuscular benzathine penicillin G: Single injection of 600,000 units for patients <27 kg OR 1.2 million units for patients ≥27 kg—preferred when adherence to oral therapy is questionable 1, 2

Critical point: No GAS isolate worldwide has ever demonstrated penicillin resistance 2

Treatment for Penicillin-Allergic Patients

Non-Anaphylactic/Non-Immediate Allergy

First-generation cephalosporins (cephalexin or cefadroxil) for 10 days are the preferred alternatives, as cross-reactivity risk is <3%. 1, 2, 3

Anaphylactic/Immediate-Type Hypersensitivity

For patients with true anaphylactic reactions to β-lactams, use clindamycin, clarithromycin, or azithromycin. 1

• Clindamycin: 600 mg/day in 2-4 divided doses for adults OR 20-30 mg/kg/day in 3 divided doses for children, for 10 days—preferred option due to ~1% resistance rate in the United States 1, 3
• Clarithromycin: For 10 days 1
• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 5

Important caveat: Macrolide resistance varies geographically (5-8% in the US, up to 20% in some European and Asian countries), so check local resistance patterns before prescribing 1, 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, 2, 3

• Azithromycin requires only 5 days due to prolonged tissue half-life 1, 5
• Shortening penicillin courses by even a few days results in appreciable increases in treatment failure 1
• Therapy can be safely delayed up to 9 days after symptom onset and still prevent acute rheumatic fever 2

Adjunctive Symptomatic Therapy

NSAIDs or acetaminophen should be used for moderate to severe symptoms or high fever as adjuncts to appropriate antibiotics. 1

• NSAIDs are more effective than acetaminophen for fever and pain control 6
• Aspirin should be avoided in children due to Reye syndrome risk 1
• Corticosteroids are NOT recommended as adjunctive therapy 1
• Medicated throat lozenges used every 2 hours are effective for symptom relief 6

Post-Treatment Management

Routine follow-up throat cultures or RADT are NOT recommended in asymptomatic patients who completed therapy. 1, 2

• Follow-up testing may be considered only in special circumstances (history of rheumatic fever, outbreaks) 1, 2
• Patients become non-contagious after 24 hours of appropriate antibiotic therapy 1, 4
• Asymptomatic household contacts should NOT be routinely tested or treated 1

Management of Treatment Failure or Recurrent Pharyngitis

For patients with persistent or recurrent symptoms shortly after completing therapy, distinguish between true treatment failure, chronic carrier with viral infection, or new GAS acquisition. 1

Treatment Options for Documented Recurrent GAS Infections

• Clindamycin: 20-30 mg/kg/day in 3 divided doses for children OR 600 mg/day in 2-4 divided doses for adults, for 10 days 1, 2
• Amoxicillin-clavulanate: 40 mg/kg/day (amoxicillin component) in 3 divided doses for children OR 500 mg twice daily for adults, for 10 days 1, 2
• Intramuscular benzathine penicillin G if compliance with oral therapy is questionable 1, 2
• Benzathine penicillin G plus rifampin: 20 mg/kg/day orally in 2 divided doses for 4 days (maximum 600 mg/day) may achieve higher eradication rates 1

Important distinction: Chronic pharyngeal GAS carriers experiencing viral infections do not ordinarily require further antimicrobial therapy, as they are unlikely to spread infection or develop complications 1

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, 3
• Do NOT use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to 10% cross-reactivity 3
• Do NOT use tetracyclines, sulfonamides, or trimethoprim-sulfamethoxazole, as high resistance exists and they are ineffective against GAS 1, 4
• Do NOT prescribe antibiotics for viral pharyngitis, as this promotes resistance without clinical benefit 1
• Do NOT use broad-spectrum cephalosporins when narrow-spectrum agents are appropriate, as this unnecessarily increases resistance pressure 4