Penicillin-induced Jarisch-Herxheimer reaction.

OBJECTIVE To report a case of Jarisch-Herxheimer reaction (JHR) in a patient with presumed neurosyphilis and HIV. CASE SUMMARY A 45-year-old HIV-positive man (CD4+ count 450 cells/mm(3) and history of AIDS-defining illness) presented with JHR after an initial intravenous dose of penicillin G for presumed neurosyphilis. The patient described feeling cold with worsening headache and chills approximately one hour after infusion of the first dose of penicillin. On examination, rigors, shallow inspirations, and chills were noted. He was afebrile, tachycardic, and tachypneic and had an oxygen saturation of 94% while breathing room air. His symptoms resolved within 10 minutes. Initially, this reaction was thought to be a result of a drug allergy, but upon further review, we determined that it was JHR. DISCUSSION It is not uncommon to confuse drug allergy with JHR. An objective causality assessment suggests that the JHR in our patient was probably related to penicillin. JHR is a self-limiting condition that warrants the continuation of antibiotic treatment in syphilis patients. CONCLUSIONS JHR should be an anticipated reaction to early doses of antibiotic treatment for treponemal diseases, such as syphilis. Treatment of JHR is largely supportive, such as administering antipyretic and antiinflammatory agents. Antibiotic treatment should be continued.