The Jarisch-Herxheimer reaction (JHR) is a transient immunological reaction seen commonly in patients during antibiotics treatment, classically in syphilis but also seen in other diseases like lyme disease and relapsing fever among others.
The Jarisch-Herxheimer reaction manifests clinically with symptoms such as fever, chills, headache and myalgias, besides exacerbation of existing cutaneous lesions.
Jarisch–Herxheimer reactions are usually not life-threatening.
It has been named after Adolf Jarisch, an Austrian dermatologist and Karl Herxheimer, a German dermatologist.
Causes and Pathophysiology
As said before, Jarisch-Herxheimer’s reaction or Herxheimer reaction was s classically described in the treatment of syphilis and was believed to be caused by the release of endotoxin-like substances when large numbers of Treponema pallidum are killed by antibiotics.
The reaction is also seen in the other diseases caused by spirochetes such as Lyme disease, relapsing fever, and leptospirosis.
Other diseases where Jarisch-Herxheimer reaction has been reported are, bartonellosis, brucellosis, trichinellosis, and African trypanosomiasis.
The exact mechanism is not clear yet.
An increase in inflammatory cytokines during the period of exacerbation, including tumor necrosis factor alpha, interleukin-6 and interleukin-8 has been noted.
The symptoms of reaction are seen between 1 and 12 hours after the first injection of antibiotics and lasts for a few hours or up to a day. It is not seen with subsequent treatment.
Patient complains of malaise, slight-to-moderate fever. There is a flush due to vasodilation. Increase in heartbeat is noted.
Any existing skin lesions become more prominent.
There is hyperventilation and hypertension followed by a drop in blood pressure due to vasodilation and declining peripheral resistance.
Blood examination would show leukocytosis.
Usually, the reaction resolves over a period of 6-12 hours.
Serological tests for syphilis are indicated if the reaction is noted unexpectedly..
No treatment is usually required for the reaction per se. It is a self-limiting condition and often resolves within 24 hours.
Symptom controlling measures may be taken in case the symptoms are severe.
Treatment of severe leptospirosis-related Jarisch-Herxheimer reaction with fluid infusion, vasopressors, corticosteroids, inotropic support and transient dialysis has been reported.