Syphilis Treatment: Benzathine Penicillin G, Serological Monitoring, and Managing Jarisch-Herxheimer Reaction in STIs

Syphilis is a sexually transmitted infection (STI) caused by the spirochete Treponema pallidum. Despite being an ancient disease, its incidence has increased in recent years, particularly among men who have sex with men. If left untreated, syphilis can progress through different clinical stages, potentially leading to irreversible cardiovascular or neurological complications [1]. The diagnosis and management of syphilis are challenging due to the diversity of its manifestations and the interpretation of serological tests.
Diving into Treatment and Monitoring
The treatment of choice for all stages of syphilis is benzathine penicillin G. This antibiotic has proven to be highly effective, even in patients co-infected with HIV [2]. However, treatment may fail in a small percentage of patients, leading to investigations into possible genetic mutations of T. pallidum related to penicillin resistance [3].
Serological monitoring is crucial to confirm cure and detect possible reinfections. It is recommended to perform non-treponemal serological tests, such as VDRL or RPR, at 3, 6, 12, and 24 months post-treatment [4]. A decrease of at least fourfold in antibody titers is indicative of an adequate serological response. If this decrease is not observed, the possibility of reinfection or treatment failure should be considered.
It is important to be aware of the Jarisch-Herxheimer reaction, an acute inflammatory response that may occur after the initiation of treatment with penicillin. Although it is generally self-limiting, it may require symptomatic management in some cases [5].
Conclusions
Syphilis remains a significant challenge in clinical practice due to its varied presentation and the need for rigorous serological monitoring. Benzathine penicillin G continues to be the treatment of choice, and serological control is essential to ensure cure and prevent complications. Ongoing education and vigilance are fundamental to controlling this rising STI.
Referencias
- [1] Syphilis
- [2] Sexually acquired syphilis: Laboratory diagnosis, management, and prevention
- [3] Association between treatment failure in patients with early syphilis and penicillin resistance-related gene mutations of Treponema pallidum: Protocol for a multicentre nested case-control study
- [4] Syphilis in Dermatology: Recognition and Management
- [5] Management issues in syphilis
Created 6/1/2025