The Jarisch-Herxheimer reaction (JHR) is a non-specific set of symptoms (fever, malaise, worsened rash, hemodynamic instability, leukocytosis) seen after treating syphillis and other spirochete induced infections. In this study 1 in 4 patients treated with 2.4 million units of benzathine penicillin G developed a short lived JHR. Those who developed the reaction were more likely HIV negative, had secondary syphillis and had successful treatment at 6 months.
References
Dionne JA, Zhu C, Mejia-Galvis J, et al. Jarisch-Herxheimer Reaction After Benzathine Penicillin G Treatment in Adults With Early Syphilis: Secondary Analysis of a Randomized Clinical Trial. JAMA Netw Open. 2025;8(2):e2459490. doi:10.1001/jamanetworkopen.2024.59490
