What is the recommended treatment for a 12-year-old with signs and symptoms of strep throat?

Treatment of Strep Throat in a 12-Year-Old

For a 12-year-old with confirmed streptococcal pharyngitis, prescribe oral amoxicillin 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days, or alternatively oral penicillin V 250 mg two to three times daily for 10 days. 1, 2

Diagnostic Confirmation Required Before Treatment

• Always confirm the diagnosis with a rapid antigen detection test (RADT) before initiating antibiotics. 1
• A positive RADT is diagnostic and does not require backup throat culture 1
• If the RADT is negative in a child or adolescent, follow up with a throat culture to rule out false negatives 1
• Do not treat based on clinical features alone—viral and bacterial pharyngitis cannot be reliably distinguished without testing 1

First-Line Antibiotic Options (No Penicillin Allergy)

Oral Therapy (Preferred)

• Amoxicillin for 10 days: 50 mg/kg once daily (maximum 1000 mg) OR 25 mg/kg twice daily (maximum 500 mg per dose) 1, 2
• Penicillin V for 10 days: 250 mg two or three times daily 1, 2, 3
• These narrow-spectrum options are preferred due to proven efficacy, safety, low cost, and minimal impact on antimicrobial resistance 1

Intramuscular Option

• Benzathine penicillin G (single dose): 1,200,000 units for patients ≥27 kg or 600,000 units for patients <27 kg 1, 2
• Consider this option when compliance with oral therapy is uncertain 1

Treatment for Penicillin-Allergic Patients

Non-Anaphylactic Penicillin Allergy

• Cephalexin for 10 days: 20 mg/kg twice daily (maximum 500 mg per dose) 2
• Cefadroxil for 10 days: 30 mg/kg once daily (maximum 1 g) 2
• First-generation cephalosporins are safe in non-anaphylactic penicillin allergy 1

Immediate-Type Hypersensitivity (Anaphylactic) to Penicillin

• Clindamycin for 10 days: 7 mg/kg three times daily (maximum 300 mg per dose) 1, 2
• Azithromycin for 5 days: 12 mg/kg once daily (maximum 500 mg) 1, 2
• Clarithromycin for 10 days: 7.5 mg/kg twice daily (maximum 250 mg per dose) 1, 2

Critical Importance of 10-Day Treatment Duration

• Complete the full 10-day course even if symptoms resolve earlier—this is essential to prevent acute rheumatic fever 1, 2
• Treatment must be initiated within 9 days of symptom onset to effectively prevent rheumatic fever 2
• The standard 10-day duration ensures complete eradication of Group A Streptococcus 1
• While some research suggests shorter courses may be effective 4, current guidelines still recommend 10 days to prevent complications 1

Adjunctive Symptomatic Treatment

• Acetaminophen or NSAIDs for moderate to severe symptoms or fever control 1, 2, 5
• Never use aspirin in children due to the risk of Reye syndrome 1, 2, 5
• Encourage adequate hydration and rest 2
• Warm salt water gargles may provide symptom relief for children old enough to gargle 5

Follow-Up and Monitoring

• Symptoms should improve within 48-72 hours of starting antibiotics 2
• Routine post-treatment throat cultures are not recommended unless symptoms persist or recur 1, 2
• If symptoms persist beyond 48-72 hours, consider treatment failure or complications 2

Common Pitfalls to Avoid

• Never prescribe antibiotics without confirming diagnosis through testing—this contributes to antimicrobial resistance and provides no benefit for viral pharyngitis 1, 5
• Avoid broad-spectrum antibiotics when narrow-spectrum penicillins or amoxicillin are effective 1
• Do not use inadequate treatment duration (less than 10 days), which may lead to treatment failure and complications 2
• Do not routinely use corticosteroids—they provide minimal benefit (approximately 5 hours of symptom reduction) and have potential adverse effects 5

Special Considerations for Recurrent Episodes

• Evaluate patients with recurrent episodes to determine whether they are experiencing true recurrent infections or are chronic carriers with superimposed viral infections 1
• Chronic carriers may test positive for Group A Streptococcus but have viral pharyngitis as the actual cause of symptoms 1

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