What are the prescription treatments for strep pharyngitis, acute tonsillitis, and scarlet fever?

Prescription Treatments for Strep Pharyngitis, Acute Tonsillitis, and Scarlet Fever

Penicillin V or amoxicillin for 10 days is the first-line treatment for group A streptococcal (GAS) pharyngitis, tonsillitis, and scarlet fever in non-allergic patients due to their proven efficacy, safety, narrow spectrum, and low cost. 1

First-Line Treatment Options

For Patients Without Penicillin Allergy:

1. Oral Penicillin V

   • Children: 250 mg twice or three times daily for 10 days
   • Adolescents and adults: 250 mg four times daily or 500 mg twice daily for 10 days
   • Strong recommendation, high-quality evidence 1

2. Oral Amoxicillin

   • 50 mg/kg once daily (maximum 1,000 mg) for 10 days
   • Alternative: 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days
   • Strong recommendation, high-quality evidence 1
   • Note: Often preferred in young children due to better taste of suspension 1

3. Intramuscular Benzathine Penicillin G (single dose)

   • <27 kg (60 lb): 600,000 units
   • ≥27 kg (60 lb): 1,200,000 units
   • Strong recommendation, high-quality evidence 1
   • Particularly useful when compliance with oral therapy is a concern 1

For Patients With Penicillin Allergy:

1. Oral Cephalexin (Keflex)

   • 20 mg/kg per dose twice daily (maximum 500 mg per dose) for 10 days
   • Strong recommendation, high-quality evidence 1
   • Avoid in patients with immediate hypersensitivity to penicillin

2. Oral Cefadroxil

   • 30 mg/kg once daily (maximum 1 g) for 10 days
   • Strong recommendation, high-quality evidence 1
   • Avoid in patients with immediate hypersensitivity to penicillin

3. Oral Clindamycin

   • 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days
   • Strong recommendation, moderate-quality evidence 1

4. Oral Azithromycin

   • 12 mg/kg once daily (maximum 500 mg) for 5 days
   • Strong recommendation, moderate-quality evidence 1
   • Note: GAS resistance to macrolides is well-known and varies geographically

5. Oral Clarithromycin

   • 7.5 mg/kg per dose twice daily (maximum 250 mg per dose) for 10 days
   • Strong recommendation, moderate-quality evidence 1
   • Note: GAS resistance to macrolides is well-known and varies geographically

Treatment for Chronic GAS Carriers

For patients who are chronic carriers of GAS with recurrent pharyngitis episodes:

1. Oral Clindamycin

   • 20-30 mg/kg per day in three doses (maximum 300 mg per dose) for 10 days
   • Strong recommendation, high-quality evidence 1

2. Penicillin and Rifampin Combination

   • Penicillin V: 50 mg/kg per day in four doses for 10 days (maximum 2,000 mg per day)
   • Rifampin: 20 mg/kg per day in one dose for last four days of treatment (maximum 600 mg per day)
   • Strong recommendation, high-quality evidence 1

3. Amoxicillin/Clavulanate (Augmentin)

   • 40 mg amoxicillin per kg per day in three doses (maximum 2,000 mg amoxicillin per day) for 10 days
   • Strong recommendation, moderate-quality evidence 1

Important Clinical Considerations

1. Duration of Therapy

   • Standard duration is 10 days for most antibiotics to prevent rheumatic fever 1
   • Exception: Azithromycin is given for 5 days due to its prolonged tissue half-life 2
   • Patients are considered non-contagious after 24 hours of antibiotic therapy 1

2. Adjunctive Therapy

   • Analgesics/antipyretics (acetaminophen, NSAIDs) may be used for moderate to severe symptoms or fever control 1
   • Aspirin should be avoided in children 1
   • Corticosteroids are not recommended 1

3. Common Pitfalls to Avoid

   • Inadequate duration: Shorter courses (except for azithromycin) may lead to treatment failure and risk of rheumatic fever
   • Poor compliance: Consider intramuscular benzathine penicillin G for patients unlikely to complete the full oral course
   • Inappropriate use in viral pharyngitis: Testing is not recommended if clinical features strongly suggest viral etiology (cough, rhinorrhea, hoarseness, oral ulcers) 1
   • Treating asymptomatic carriers: Generally not recommended unless specific risk factors are present 1

4. Special Populations

   • Children <3 years: Testing and treatment generally not recommended unless specific risk factors exist 1
   • Patients with history of rheumatic fever: Require particularly careful treatment and follow-up 1

By following these evidence-based treatment recommendations, clinicians can effectively manage strep pharyngitis, acute tonsillitis, and scarlet fever while minimizing complications and antibiotic resistance.