What is the most likely cost-effective treatment for a 9-year-old male with fever, tonsillar exudates, and anterior cervical lymphadenopathy, without cough?

Treatment for Group A Streptococcal Pharyngitis

The most cost-effective treatment for this 9-year-old with presumed Group A streptococcal pharyngitis is oral penicillin V or amoxicillin for 10 days, after confirming the diagnosis with a rapid antigen detection test (RADT) and/or throat culture. 1

Clinical Presentation Analysis

This patient has a modified Centor score of 4 (fever, tonsillar exudates, anterior cervical lymphadenopathy, absence of cough), which corresponds to a 51-56% probability of Group A streptococcal (GAS) infection. 1 The absence of cough is particularly important, as cough strongly suggests viral etiology and is a key distinguishing feature. 1, 2

The clinical features present are classic for GAS pharyngitis:

• Fever, tonsillar exudates, and tender anterior cervical adenopathy are the hallmark triad 1, 3
• Age 5-15 years is the peak incidence group for GAS pharyngitis 1
• Absence of viral features (no cough, rhinorrhea, conjunctivitis, or hoarseness) makes bacterial infection more likely 1, 2

Diagnostic Confirmation Required

Do not treat empirically based on clinical features alone. 1 Even with a high Centor score, microbiological confirmation is mandatory:

• Perform a rapid antigen detection test (RADT) immediately - a positive result is diagnostic and allows immediate treatment 1
• If RADT is negative, obtain a backup throat culture - this is essential in children and adolescents because RADT sensitivity is approximately 86-95%, meaning false negatives occur 1
• Culture remains the gold standard with results available in 18-24 hours 1, 4

First-Line Treatment: Penicillin or Amoxicillin

Once GAS is confirmed, prescribe oral penicillin V or amoxicillin for 10 days. 1 These are recommended as first-line therapy due to:

• Narrow spectrum of activity (minimizes resistance development) 1
• Few adverse effects 1
• Modest cost (most cost-effective option) 1
• Strong evidence base with high-quality data 1

Specific Dosing Regimens

Penicillin V (oral):

• Children: 250 mg two or three times daily for 10 days 1

Amoxicillin (oral):

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

Penicillin G benzathine (intramuscular):

• Single dose of 600,000 units if <27 kg (60 lbs) or 1,200,000 units if ≥27 kg 1
• Consider this option if compliance with oral therapy is a concern 1

Alternative Antibiotics for Penicillin Allergy

If the patient has a documented penicillin allergy:

First-generation cephalosporins (avoid if history of anaphylaxis to penicillin):

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

Non-beta-lactam alternatives:

• Clindamycin: 7 mg/kg per dose three times daily for 10 days 1
• Clarithromycin or azithromycin (macrolides) 1

Important caveat: Macrolides like azithromycin are listed as alternatives but should be used cautiously due to increasing GAS resistance rates in some regions. 1

Symptomatic Management

Add adjunctive therapy for symptom relief:

• Acetaminophen or NSAIDs for fever and throat pain (NSAIDs are more effective than acetaminophen for pharyngitis pain) 1, 5
• Never use aspirin in children due to Reye's syndrome risk 1
• Do not use corticosteroids routinely - they provide only minimal symptom reduction and are not recommended 1, 5

Critical Pitfalls to Avoid

Do not treat without microbiological confirmation - clinical features alone cannot distinguish GAS from viral pharyngitis, and overtreatment contributes to antibiotic resistance and unnecessary costs. 1, 6

Do not use broad-spectrum antibiotics - they are more expensive, have more side effects, and promote resistance without improving outcomes. 1

Do not order follow-up cultures routinely - post-treatment testing is unnecessary unless the patient remains symptomatic, is at high risk for rheumatic fever, or has recurrent symptoms. 1

Do not test or treat asymptomatic household contacts - they are likely carriers and do not require treatment. 1

Treatment Goals and Expected Outcomes

Antibiotic therapy for confirmed GAS pharyngitis achieves:

• Prevention of acute rheumatic fever (the primary indication for treatment) 1
• Reduction in symptom duration by approximately 1 day 1, 5
• Prevention of suppurative complications (peritonsillar abscess, cervical lymphadenitis) 1, 4
• Reduced transmission to contacts 7

The 10-day duration is specifically designed to eradicate GAS and prevent rheumatic fever, which remains the standard despite some studies suggesting shorter courses may be effective. 1