Jarisch-Herxheimer reaction

Background

Jarisch-Herxheimer reaction (JHR), 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 occurs following antibiotic treatment for a number of spirochetal and bacterial infections. 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. Both penicillin and tetracycline can induce JHR. JHR can also occur following treatment of tick-borne relapsing fever (TBRF). These reactions tend to occur within two hours of antibiotic administration. Thus, observation for several hours after treatment is recommended. The reaction lasts for a few hours or up to a day. It is not usually seen with subsequent treatment.

Signs & Symptoms

• Malaise
• Fever
• Rigors
• Flushing (due to vasodilation)
• Hypotension
• Tachycardia
  • Tachycardia and hyperventilation are accompanied by hypertension, and then by a drop in blood pressure due to vasodilation and declining peripheral pulse.

Complications

• The mortality rate from JHR in louse-borne relapsing fever (LBRF) in the absence of adequate monitoring and resuscitation measures is ~ 5%.

Sources

Harrison's Principles of Internal Medicine