herxing

English

Etymology

Shortened from Jarisch-Herxheimer reaction, which in turn derives from the names of Adolf Jarisch and Karl Herxheimer, physicians who separately described the reaction in syphilis patients.

Verb

herxing

present participle and gerund of herx (“to experience Jarisch–Herxheimer reaction”)

Noun

herxing (uncountable)

(medicine, informal) Jarisch–Herxheimer reaction, a negative reaction to antibiotic treatment.
- 1997 February, Edward McSweegan, “TNF antibodies get new lease”, in Nature Medicine, volume 3, number 2, page 130:
  Brenner’s own experience with “herxing” (a common phrase among Lyme patients) started 2 or 3 hours after his first antibiotic treatment.
- 2013 July, Centers for Disease Control and Prevention, “Article Corrections”, in Gifted Child Today, volume 36, number 3, page 215:
  Moreover, the Jarish–Herxheimer reaction (sometimes referred to as “herxing”) is a rare syndrome seen within the first 48 hr of starting antibiotic treatment for some spirochetal diseases; the belief that “herxing” causes ongoing symptom flares in patients with Lyme disease is a fallacy for which there is no objective evidence.
- 2019 July 22, Molly Fischer, “Maybe it’s Lyme”, in New York magazine:
  Herxes, or “herxing,” are a great bugbear in the world of chronic Lyme. The term is drawn from the Jarisch-Herxheimer reaction, originally identified in the context of syphilis. It refers to a brief, severe reaction that can take place within the first few days of antibiotic treatment; as bacteria die off and release endotoxins, a patient experiences fever, chills, and sometimes dangerously low blood pressure.
- 2021 December, Sam Kriss, “It’s not all in your head”, in First Things: A Monthly Journal of Religion and Public Life, page 12:
  He sets the machine to the frequency that’s supposed to kill the Lyme spirochete, turns it on, and immediately starts Herxing.

Usage notes

The informal terms Herx and herxing are common in discussions of Lyme disease, especially among patients of the disease and their supporters.