Jarisch-Herxheimer reaction

Background

Jarisch-Herxheimer reaction (also known as the Herxheimer's reaction) is a systemic reaction that believed to be caused by a reaction to endotoxins released by the death of harmful organisms within the body. It was classically described in the treatment of syphilis. It is believed to be caused by release of endotoxin-like substances when large numbers of Treponema Pallidum are killed by antibiotics. It also has been documented in tick-borne diseases such as Lyme disease.

Presentation

It resembles bacterial sepsis. The reaction starts between 1 to 12 hours after the first injection of antibiotics and lasts for a few hours or up to a day. It is not usually seen with subsequent treatment.

• Malaise, slight-to-moderate pyrexia
• Flushing (due to vasodilation)
• Tachycardia
  • Tachycardia and hyperventilation are accompanied by hypertension, and then by a drop in blood pressure due to vasodilation and declining peripheral pulse.

Sources

Harrison's Principles of Internal Medicine