Treatment of Streptococcal Pharyngitis

First-Line Antibiotic Treatment

The American Academy of Pediatrics and the Infectious Diseases Society of America recommend penicillin V (250 mg three to four times daily or 500 mg twice daily for 10 days) or amoxicillin (50 mg/kg once daily, maximum 1000 mg, for 10 days) as the first-line treatment for streptococcal pharyngitis, regardless of the presence of inflamed gums and mouth ulcers 1
Penicillin V is the drug of choice for confirmed Group A streptococcal pharyngitis due to its narrow spectrum, proven efficacy, safety profile, and low cost 2, 3, 1
The standard regimen for adults and older children is penicillin V 250 mg three to four times daily or 500 mg twice daily for 10 days, while younger children should receive amoxicillin 50 mg/kg once daily (maximum 1000 mg) for 10 days 1
The full 10-day course of antibiotic therapy is essential to achieve maximal pharyngeal eradication of Group A Streptococcus and prevent acute rheumatic fever 4, 1

The presence of inflamed gums and mouth ulcers does not change the antibiotic selection for streptococcal pharyngitis, and symptomatic management with acetaminophen or NSAIDs (such as ibuprofen) should be added to antibiotic therapy 4
Corticosteroids are not recommended as adjunctive therapy for streptococcal pharyngitis 2, 4

For patients with a documented penicillin allergy, first-generation cephalosporins (such as cephalexin or cefadroxil) are preferred for non-immediate penicillin allergies, while clindamycin, azithromycin, or clarithromycin are recommended for immediate/anaphylactic penicillin allergies 4, 1
The cross-reactivity risk between penicillin and cephalosporins is approximately 0.1% in patients with non-severe, delayed penicillin reactions, but up to 10% in patients with immediate/anaphylactic penicillin reactions 4

Shorter courses of antibiotic therapy than recommended (except azithromycin's 5-day regimen) should be avoided, as they increase the risk of treatment failure and rheumatic fever 4, 1
Antibiotics should not be used for symptom relief alone in patients with 0-2 Centor criteria, and cephalosporins should not be used in patients with immediate/anaphylactic penicillin reactions due to the risk of cross-reactivity 2, 4
Macrolides (such as azithromycin or clarithromycin) should not be assumed to be equivalent to penicillin, as resistance rates vary geographically and can lead to treatment failure 4

Patients should be re-evaluated if symptoms worsen after 72 hours of appropriate antibiotic therapy, or if new symptoms develop suggesting complications (peritonsillar abscess, cervical lymphadenitis) 2
If symptoms persist after completing the full 10-day course of antibiotic therapy, a throat culture or rapid antigen test should be obtained to determine if Group A Streptococcus is still present, and alternative treatments (such as clindamycin or amoxicillin-clavulanate) may be necessary 5