What describes a Jarisch-Herxheimer reaction?

The Jarisch-Herxheimer reaction is characterized by fever and chills that occur after the initiation of treatment for syphilis, particularly after the administration of penicillin. This reaction is thought to be caused by the release of endotoxins from the lysis of the Treponema pallidum bacteria as they are destroyed by antibiotic therapy. It typically arises within hours of the treatment and can last for a day or two.

Understanding this reaction is important when treating syphilis, as it can cause significant distress for patients who may mistakenly interpret these symptoms as a sign that their condition is worsening. Prompt recognition of the Jarisch-Herxheimer reaction allows healthcare providers to reassure patients that this is a common and self-limiting response to antibiotic treatment. The reaction does not indicate an allergy to medications or a direct inflammatory response unrelated to the treatment of syphilis, which differentiates it from other potential adverse drug reactions.