In a patient with fever, polyarthralgia, and positive antistreptolysin O, what is the recommended prophylaxis?

In a patient presenting with fever, polyarthralgia, and a positive antistreptolysin O (ASO) titer, the clinical picture is suggestive of rheumatic fever, especially considering the history of recent streptococcal infection. Prophylaxis with benzathine penicillin G is indicated to prevent the recurrence of rheumatic fever episodes, which can lead to serious complications such as rheumatic heart disease.

Benzathine penicillin G is the preferred choice for secondary prophylaxis in individuals with a history of rheumatic fever due to its long-acting formulation that provides sustained protection against group A streptococcal infections. It effectively reduces the risk of recurrent rheumatic fever, especially in at-risk populations.

Other antibiotics listed do not serve as effective prophylaxis in this context. Doxycycline and trimethoprim/sulfamethoxazole are not standard treatments for preventing rheumatic fever. Erythromycin can be used as an alternative for those allergic to penicillin, but it is generally not the first-line approach. Thus, benzathine penicillin G is the most appropriate choice for managing this specific clinical scenario.