How should I manage a 2‑year‑old child with confirmed group A streptococcal infection and respiratory syncytial virus, assuming no penicillin allergy?

Management of a 2-Year-Old with Confirmed Group A Streptococcal Infection and RSV

Treat the streptococcal pharyngitis with oral amoxicillin 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for a full 10 days, while providing supportive care only for the concurrent RSV infection.

Antibiotic Treatment for Group A Streptococcus

First-Line Therapy

• Amoxicillin is the drug of choice for confirmed GAS pharyngitis in children, offering proven efficacy, zero documented resistance worldwide, excellent safety, better palatability than penicillin V, and low cost. 1, 2
• Dosing: 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days. 1, 2
• No documented penicillin resistance exists anywhere in the world among Group A Streptococcus, ensuring reliable bacterial eradication. 1, 2

Mandatory Treatment Duration

• A complete 10-day course is essential to achieve maximal pharyngeal eradication and prevent acute rheumatic fever, even if symptoms resolve within 3–4 days. 3, 1
• Shortening the course by even a few days markedly increases treatment failure rates and rheumatic fever risk. 1, 2
• The primary goal is preventing acute rheumatic fever and suppurative complications (peritonsillar abscess, cervical lymphadenitis), not merely symptom relief. 3

Alternative Regimens (If Penicillin Allergy Present)

Non-Immediate (Delayed) Penicillin Allergy

• First-generation cephalosporins (cephalexin 20 mg/kg twice daily, maximum 500 mg per dose) for 10 days are preferred, with only 0.1% cross-reactivity risk. 1

Immediate/Anaphylactic Penicillin Allergy

• All β-lactam antibiotics must be avoided due to up to 10% cross-reactivity risk. 1
• Clindamycin 7 mg/kg three times daily (maximum 300 mg per dose) for 10 days is the preferred alternative, with only ~1% resistance among U.S. GAS isolates. 1, 2
• Azithromycin 12 mg/kg once daily (maximum 500 mg) for 5 days is acceptable but has 5–8% macrolide resistance in the United States. 1

Management of Concurrent RSV Infection

Supportive Care Only

• RSV bronchiolitis management is purely supportive—there is no specific antiviral therapy recommended for routine clinical use. 4
• Provide feeding support and oxygen supplementation as needed until the infant's immune system controls the infection. 4
• Ribavirin is the only licensed drug for RSV but is not recommended for routine use due to drug toxicity and minimal clinical benefit. 4

Monitoring and Symptom Management

• Acetaminophen or ibuprofen may be offered for fever, sore throat, or systemic discomfort associated with either infection. 1, 2
• Aspirin must be avoided in children due to the risk of Reye syndrome. 1, 2
• Monitor for respiratory distress (increased work of breathing, hypoxia) that may require hospitalization or oxygen therapy. 4

Critical Pitfalls to Avoid

• Do not withhold or delay antibiotic treatment for GAS simply because the child has concurrent RSV—both conditions require management. 3
• Do not shorten the antibiotic course below 10 days (except azithromycin's 5-day regimen), as this dramatically increases treatment failure and rheumatic fever risk. 1, 2
• Do not prescribe antibiotics for RSV—it is a viral infection and antibiotics provide no benefit. 4
• Do not use trimethoprim-sulfamethoxazole, tetracyclines, or sulfonamides for GAS, as these agents fail to eradicate streptococci effectively. 1
• Corticosteroids are not recommended as adjunctive therapy for streptococcal pharyngitis. 1, 2

Infection Control and Household Contacts

• Asymptomatic household contacts do not require routine testing or treatment for GAS pharyngitis. 3
• Implement standard infection control measures to minimize nosocomial RSV transmission if hospitalized, as nosocomial RSV infections are associated with poorer outcomes. 4
• The child may return to daycare 24 hours after starting antibiotics for GAS, though RSV symptoms may persist longer. 2

When to Reassess

• Re-evaluate within 48–72 hours if no clinical improvement occurs, as this may indicate non-compliance, treatment failure, or a suppurative complication requiring imaging or drainage. 1
• Routine post-treatment throat cultures are not indicated for asymptomatic patients who completed therapy. 1, 2