How is streptococcal pharyngitis diagnosed and treated to prevent rheumatic fever?

• A. Rapid antigen detection test or throat culture; penicillin or amoxicillin for 10 days.
• B. Clinically diagnosed by sore throat alone; antibiotics for 5 days.
• C. Throat culture only; azithromycin for 5 days.
• D. No testing and no antibiotics; treat with supportive care only.

Answer: (A)

Preventing rheumatic fever hinges on confirming infection with group A Streptococcus and eradicating it with a full antibiotic course. A rapid antigen detection test or throat culture is used to diagnose GAS pharyngitis, because many sore throats are viral and won’t benefit from antibiotics. If GAS is confirmed, a 10-day course of penicillin or amoxicillin is used to reliably eradicate the bacteria and prevent rheumatic fever; shorter courses don’t provide the same protection and treating based only on symptoms is insufficient. If penicillin allergy exists, choose an appropriate alternative such as a cephalosporin (if there’s no anaphylaxis) or a macrolide.