Treatment of Streptococcal Pharyngitis in a 9-Year-Old Child
For this 9-year-old male (53.4 lbs/24.2 kg) with confirmed streptococcal pharyngitis, prescribe amoxicillin 50 mg/kg once daily (maximum 1000 mg) for 10 full days, which equals approximately 1200 mg daily—round down to 1000 mg once daily for 10 days. 1
First-Line Antibiotic Treatment
Penicillin and amoxicillin are the drugs of choice based on their narrow spectrum, proven efficacy, safety profile, and low cost. 1 No Group A streptococcus (GAS) isolate has ever demonstrated penicillin resistance anywhere in the world. 1
Dosing Options for This Patient:
Preferred option:
- Amoxicillin 50 mg/kg once daily (1000 mg for this patient) for 10 days 1
- Amoxicillin is preferred over penicillin V in children due to better palatability and once-daily dosing improves adherence 2
Alternative oral options:
- Penicillin V 250 mg twice or three times daily for 10 days 1
- Amoxicillin 25 mg/kg (approximately 600 mg for this patient) twice daily for 10 days 1
Intramuscular option (if adherence concerns):
- Benzathine penicillin G 600,000 units as a single dose (for patients <27 kg) 1
- This patient at 24.2 kg qualifies for the lower dose 1
Critical Treatment Principles
The full 10-day course must be completed even if symptoms resolve earlier, as this duration is necessary to prevent acute rheumatic fever. 1, 2 Therapy can be safely delayed up to 9 days after symptom onset and still prevent rheumatic fever, so waiting 24-48 hours for culture confirmation does not increase risk. 1
The patient becomes non-contagious after 24 hours of antibiotic therapy and can return to school/activities at that point. 1, 2
Penicillin-Allergic Patients
If this patient had a penicillin allergy (which is not indicated), treatment options depend on allergy type:
For non-anaphylactic penicillin allergy:
- Cephalexin 20 mg/kg/dose twice daily (maximum 500 mg/dose) for 10 days 1
- Cefadroxil 30 mg/kg once daily (maximum 1 g) for 10 days 1
For anaphylactic penicillin allergy:
- Clindamycin 7 mg/kg/dose three times daily (maximum 300 mg/dose) for 10 days 1
- Azithromycin 12 mg/kg once daily (maximum 500 mg) for 5 days 1
- Clarithromycin 7.5 mg/kg/dose twice daily (maximum 250 mg/dose) for 10 days 1
Important caveat: Macrolide resistance (azithromycin, clarithromycin) varies geographically and temporally in the United States, with some areas showing significant resistance. 1, 3, 4 These should only be used when beta-lactams cannot be given. 3
Symptomatic Management
Adjunctive therapy is recommended for symptom control:
- NSAIDs (ibuprofen) or acetaminophen for moderate to severe throat pain or high fever 1
- NSAIDs are more effective than acetaminophen for pain and fever control in streptococcal pharyngitis 1, 5
- Never use aspirin in children due to risk of Reye syndrome 1
- Corticosteroids are not recommended despite minimal symptom reduction (approximately 5 hours), given the self-limited nature of the illness and potential adverse effects 1
Common Pitfalls to Avoid
Do not prescribe antibiotics before confirming GAS infection with rapid antigen detection test (RADT) or throat culture, unless you plan to discontinue if testing is negative. 1 Nationally, 70% of patients with sore throats receive antibiotics, but only 20-30% of pediatric pharyngitis cases are actually GAS. 1, 2
Do not order post-treatment cultures or RADT routinely after completing therapy, as these are not recommended except in special circumstances. 1
Do not test or treat asymptomatic household contacts unless there are specific risk factors. 1
Ensure the oral route is appropriate: The oral route should not be relied upon in patients with severe illness, nausea, vomiting, or intestinal hypermotility. 6 If adherence is questionable, consider intramuscular benzathine penicillin G instead. 1
When to Reevaluate
Reassess if: