What is the recommended treatment for a pediatric patient with Group A Streptococcal (GAS) pharyngitis?

Treatment of Group A Streptococcal (GAS) Pharyngitis in Pediatric Patients

First-Line Treatment: Penicillin or Amoxicillin

Penicillin V or amoxicillin for 10 days is the recommended first-line treatment for pediatric patients with confirmed GAS pharyngitis, based on their narrow spectrum of activity, proven efficacy in preventing acute rheumatic fever, minimal adverse effects, and low cost. 1

Specific Dosing Regimens

For children without penicillin allergy:

• Amoxicillin 50 mg/kg once daily (maximum 1,000 mg) for 10 days is highly effective and may improve adherence compared to multiple daily dosing 1
• Alternative: Amoxicillin 25 mg/kg twice daily for 10 days 1
• Penicillin V 250 mg two or three times daily for 10 days 1
• Amoxicillin is preferred over penicillin V in younger children due to better palatability and availability as suspension 2

The evidence supporting amoxicillin is particularly strong. A randomized trial demonstrated that amoxicillin 40 mg/kg/day achieved 87.9% clinical cure versus 70.9% with standard-dose penicillin V (p=0.025), and 79.3% bacteriologic cure versus 54.5% with penicillin V (p=0.005) 3. Additionally, once-daily amoxicillin 1500 mg (or 750 mg if ≤30 kg) was non-inferior to twice-daily penicillin V in a well-powered study of 353 children 4.

Critical Treatment Duration

The full 10-day course is absolutely essential to achieve maximal pharyngeal eradication of GAS and prevent acute rheumatic fever, even though symptoms typically resolve within 3-4 days. 1, 2 Shortening the course by even a few days results in appreciable increases in treatment failure rates and rheumatic fever risk 2.

Treatment for Penicillin-Allergic Patients

The choice of alternative antibiotic depends critically on the type of allergic reaction 5, 2:

Non-Anaphylactic (Delayed) Penicillin Allergy

First-generation cephalosporins are the preferred first-line alternatives with strong, high-quality evidence:

• Cephalexin 20 mg/kg per dose twice daily (maximum 500 mg per dose) for 10 days 5, 2
• Cefadroxil 30 mg/kg once daily (maximum 1 gram) for 10 days 5, 2, 6

The cross-reactivity risk with first-generation cephalosporins is only 0.1% in patients with non-severe, delayed penicillin reactions 2. These agents have narrow spectrum activity, proven efficacy, and low cost 2.

Immediate/Anaphylactic Penicillin Allergy

Patients with immediate hypersensitivity reactions (anaphylaxis, angioedema, respiratory distress, or urticaria within 1 hour) must avoid ALL beta-lactam antibiotics, including cephalosporins, due to up to 10% cross-reactivity risk. 1, 5, 2

Preferred alternatives for anaphylactic allergy:

• Clindamycin 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days 1, 5, 2
  • Clindamycin has strong, moderate-quality evidence and demonstrates high efficacy even in chronic carriers 5, 2
  • Resistance remains very low at approximately 1% in the United States 5, 2

Acceptable macrolide alternatives:

• Azithromycin 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 5, 7

  • Azithromycin is the ONLY antibiotic requiring just 5 days due to its prolonged tissue half-life 5, 2
  • However, macrolide resistance is 5-8% in the United States and varies geographically 5, 2

• Clarithromycin 7.5 mg/kg per dose twice daily (maximum 250 mg per dose) for 10 days 1, 5, 2

  • Same resistance concerns as azithromycin 2

Clindamycin is preferred over macrolides in areas with high macrolide resistance rates or when reliability is paramount, given its substantially lower resistance rate (1% vs 5-8%). 5, 2

Diagnostic Confirmation Required

Testing with rapid antigen detection test (RADT) or throat culture is essential before prescribing antibiotics, as clinical features alone cannot reliably distinguish GAS from viral pharyngitis. 1, 5

• A positive RADT is diagnostic and does not require backup culture 1, 5
• A backup throat culture should be performed in children and adolescents with negative RADT results 1
• Testing is generally not recommended in children younger than 3 years unless risk factors exist (such as an older sibling with GAS infection), as the illness is uncommon in this age group 1

Do not test or treat if clinical features strongly suggest viral etiology: cough, rhinorrhea, hoarseness, conjunctivitis, or oral ulcers 1, 8

Adjunctive Symptomatic Treatment

For moderate to severe symptoms or high fever:

• Acetaminophen or NSAIDs (such as ibuprofen) should be considered as adjunctive therapy 1, 8
• Aspirin must be avoided in children due to the risk of Reye syndrome 1, 8
• Corticosteroids are not recommended 1, 8

Special Considerations for Recurrent Pharyngitis

Patients with recurrent episodes of pharyngitis and laboratory evidence of GAS may be chronic carriers experiencing repeated viral infections rather than true recurrent bacterial infections. 1, 5

• Chronic carriers generally do not require antimicrobial therapy, as they are unlikely to spread GAS and are at little risk for complications 1, 5
• If treatment of chronic carriers is necessary, clindamycin demonstrates substantially higher eradication rates than penicillin or amoxicillin 2

Antibiotics for chronic carriers may be considered in specific circumstances: community outbreak of acute rheumatic fever or invasive GAS, family or personal history of acute rheumatic fever, excessive family anxiety, or when tonsillectomy is being considered solely because of carrier status 1.

Critical Pitfalls to Avoid

• Never prescribe antibiotics for viral pharyngitis - this provides no benefit and contributes to antibiotic resistance 8
• Never use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to 10% cross-reactivity risk 5, 2
• Never shorten antibiotic courses below 10 days (except azithromycin's 5-day regimen) - this dramatically increases treatment failure and rheumatic fever risk 1, 2
• Never prescribe broad-spectrum cephalosporins (cefdinir, cefixime, cefpodoxime) when narrow-spectrum first-generation agents are appropriate 2
• Never rely on clinical features alone to diagnose GAS pharyngitis - no clinical signs or scores have adequate predictive value 8
• Never use trimethoprim-sulfamethoxazole (Bactrim) for strep throat due to high resistance rates (50%) 5

Post-Treatment Follow-Up

Routine follow-up throat cultures or RADT are not recommended for asymptomatic patients who have completed therapy. 1, 2 Testing may be considered only in special circumstances, such as patients with a history of rheumatic fever 2.