Contents

SynopsisCodesLook ForDiagnostic PearlsDifferential Diagnosis & PitfallsBest TestsManagement PearlsTherapyDrug Reaction DataReferences
Jarisch-Herxheimer reaction
Other Resources UpToDate PubMed

Jarisch-Herxheimer reaction

Contributors: Isabella J. Tan, Zizi Yu, Bernard Cohen MD, Susan Burgin MD
Other Resources UpToDate PubMed

Synopsis

A Jarisch-Herxheimer reaction (JHR) is a short-lived immunologic response to antimicrobial treatment of syphilis characterized by fever, onset of constitutional symptoms, and worsening of rash. It typically begins 2-8 hours after the initial dose of antibiotic is given and resolves spontaneously within 24 hours. It occurs in 50%-75% of patients undergoing treatment for primary or secondary syphilis and in 16% of patients being treated for early latent infection. JHR is not generally seen with subsequent antibiotic courses. It is rarely seen in late syphilis, but when it occurs, it is severe.

Initially, there is abrupt onset of high fever with associated chills, myalgias, headache, tachycardia, lymphadenopathy, and sometimes hypotension. Rarer manifestations include meningitis, abnormal renal or liver function, changes in mental state, and seizures. In primary syphilis, extension of ulceration of the primary chancre can be seen. In secondary syphilis, the rash worsens and may become vesicular or urticarial. In neurosyphilis, when it does occur, the JHR causes severe exacerbation of underlying neurologic or psychiatric symptoms and signs.

JHR can induce uterine contractions, premature labor, and changes in fetal activity and heart rate in pregnant patients, necessitating close fetal monitoring. Infants with congenital syphilis who undergo treatment with penicillin may also develop JHR. This typically affects infants younger than age 6 months and can lead to severe outcomes, including respiratory distress and changes in heart rate, necessitating close monitoring during treatment.

A high rapid plasma reagin (RPR) titer is a risk factor, while prior treatment with penicillin is a protective factor against the reaction. The reaction has also been shown to occur with greater frequency and severity in immunocompromised individuals.

A JHR-like reaction has been reported following treatment of other spirochete-mediated diseases such as Lyme disease, leptospirosis, and relapsing fever (tick borne, hard tick borne, louse borne), and during treatment of a wide variety of other infectious diseases, including brucellosis and trypanosomiasis.

The cause of the JHR is unknown, but it is hypothesized that the release of bacterial toxins and/or lipoproteins, elevated cytokines such as tumor necrosis factor (TNF), interleukin (IL)-6 and IL8, or immune complexes may be at play. The reaction may be the body's natural systemic inflammatory response to successful antibiotic-mediated destruction of bacterial cell membranes and the release of bacterial toxins into the bloodstream.

Codes

ICD10CM:
T36.95XA – Adverse effect of unspecified systemic antibiotic, initial encounter
T78.40XA – Allergy, unspecified, initial encounter

SNOMEDCT:
10803007 – Jarisch Herxheimer reaction

Look For

Subscription Required

Diagnostic Pearls

Subscription Required

Differential Diagnosis & Pitfalls

To perform a comparison, select diagnoses from the classic differential

Subscription Required

Best Tests

Subscription Required

Management Pearls

Subscription Required

Therapy

Subscription Required

Drug Reaction Data

Subscription Required

References

Subscription Required

Last Reviewed:10/07/2024
Last Updated:10/08/2024
Copyright © 2024 VisualDx®. All rights reserved.
Jarisch-Herxheimer reaction
Print  
A medical illustration showing key findings of Jarisch-Herxheimer reaction : Chills, Fever, Flushing, Headache, Rigors, Myalgia
Copyright © 2024 VisualDx®. All rights reserved.