What is the recommended treatment for strep throat?

Treatment of Strep Throat

Penicillin or amoxicillin for 10 days is the recommended first-line treatment for strep throat due to proven efficacy, safety, narrow spectrum, and low cost. 1, 2

First-Line Treatment for Patients Without Penicillin Allergy

Oral penicillin V is the gold standard treatment with the following dosing 1, 2:

• Children: 250 mg two or three times daily for 10 days
• Adolescents and adults: 250 mg four times daily OR 500 mg twice daily for 10 days

Oral amoxicillin is equally effective and often preferred in young children due to better palatability 1, 2:

• 50 mg/kg once daily (maximum 1,000 mg) for 10 days, OR
• 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days

Intramuscular benzathine penicillin G should be used when compliance with oral therapy is questionable 1, 2:

• < 60 lb (27 kg): 600,000 units as a single dose
• ≥ 60 lb: 1,200,000 units as a single dose

The 10-day duration is critical for maximizing pharyngeal eradication of Group A streptococcus and preventing rheumatic fever, despite the self-limited nature of the infection. 1, 2 Penicillin resistance has never been documented in Group A streptococcus. 1

Treatment for Patients With Penicillin Allergy

The choice depends on the type of allergic reaction 1, 3, 2:

For Non-Anaphylactic Penicillin Allergy (e.g., rash without respiratory/cardiovascular symptoms):

First-generation cephalosporins for 10 days 1, 3, 2:

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

Cross-reactivity risk with penicillin is less than 3%. 4

For Anaphylactic Penicillin Allergy (immediate hypersensitivity):

Clindamycin for 10 days 1, 3, 2:

• 7 mg/kg per dose three times daily (maximum 300 mg per dose)

Alternative macrolides (with important caveats about resistance) 1, 3:

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

Critical caveat: Macrolide resistance varies geographically and temporally, with significant resistance documented in some U.S. regions. 1, 3, 5, 6, 7 Susceptibility testing should be performed when using azithromycin. 5 In areas with high macrolide resistance rates, these agents should be avoided. 3, 7

Diagnostic Confirmation Before Treatment

Do not treat empirically without testing unless clinical features overwhelmingly suggest viral etiology (cough, rhinorrhea, hoarseness, oral ulcers). 1, 2

Rapid antigen detection test (RADT) is the preferred initial test 3, 2:

• A positive RADT is diagnostic and requires no backup culture 3
• A negative RADT in children and adolescents requires backup throat culture due to lower sensitivity 2, 6

Clinical features increasing suspicion for strep throat include 1, 2, 6:

• Sudden onset of sore throat
• Fever
• Tonsillopharyngeal inflammation or exudates
• Tender anterior cervical lymphadenopathy
• Age 3-15 years
• Absence of cough (cough suggests viral etiology)

Adjunctive Symptomatic Treatment

Acetaminophen or NSAIDs can be used for moderate to severe symptoms or high fever. 1, 3, 2

Avoid aspirin in children due to risk of Reye syndrome. 1, 3, 2

Corticosteroids are not recommended for routine treatment of strep pharyngitis. 1, 3, 2

Management of Recurrent Episodes

For patients with recurrent positive cultures shortly after completing treatment 1, 3, 2:

1. Confirm each episode with RADT or throat culture to distinguish true reinfection from chronic carriage with viral infections 3
2. Retreat with the same initial agent if compliance was adequate 1, 2
3. Use intramuscular benzathine penicillin G if oral compliance is questionable 1, 2
4. Consider clindamycin or amoxicillin/clavulanate for chronic carriers, as these achieve higher pharyngeal eradication rates 1, 2

Critical Pitfalls to Avoid

Do not overtreat viral pharyngitis: 60% or more adults with sore throat receive antibiotics, but only 10% have strep throat. 6 Testing before treatment prevents unnecessary antibiotic use. 2

Do not use short-course therapy with penicillin: While some newer antibiotics (cefdinir, cefpodoxime, azithromycin) are FDA-approved for 5-day courses, penicillin and amoxicillin require the full 10 days for optimal eradication. 1, 8 Short-course penicillin therapy has inferior bacteriologic cure rates. 1

Do not routinely perform post-treatment cultures: Follow-up testing is not recommended for asymptomatic patients who completed treatment. 1, 2

Do not test or treat asymptomatic household contacts: Routine testing of contacts is not warranted. 1

Recognize geographic macrolide resistance: In areas where clarithromycin or azithromycin resistance exceeds 10-15%, these agents should not be first-line alternatives for penicillin-allergic patients. 3, 6, 7