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infectious-disease

Jarisch-Herxheimer Reaction Severity Assessment

Acute febrile reaction occurring within 24 h of antibiotic treatment for spirochaete infections (syphilis, leptospirosis, Lyme, relapsing fever). Categorise severity for management.

Score interpretation

Mild reaction 1

→ Continue treatment. Antipyretics (paracetamol), oral fluids, observation. Reassure: typically self-limiting within 24 h. Symptoms peak at 6–8 h.

Moderate reaction 2

→ Admission for observation. IV fluids, paracetamol; corticosteroids (e.g. prednisolone 60 mg) controversial — generally NOT recommended outside neurosyphilis/cardiovascular syphilis. Continue antibiotics.

Severe reaction 3

→ Critical care. Aggressive fluid resuscitation, vasopressors if needed. IV methylprednisolone 1 mg/kg may be considered. Continue antibiotics — interrupting risks worsening untreated spirochaetosis. Cardiac and respiratory monitoring.

Pregnancy reaction 4

→ Continuous fetal monitoring. Treat maternal fever aggressively (paracetamol, cooling). Steroids in syphilis treatment in 2nd/3rd trimester (prednisolone 20 mg TDS for 3 days starting 24 h before penicillin). Joint obstetric and ID care.

Interpretation bands for the Jarisch-Herxheimer. Apply clinical judgement and local guidance.

References

Related

Curated clinical cross-links plus same-class fallbacks.

Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.