The Jarisch-Herxheimer reaction in leptospirosis: possible pathogenesis and review.

The importance of treating leptospirosis with penicillin is emphasized by two case reports and a review documenting the occurrence of the Jarisch-Herxheimer reaction (JHR) in patients with this bacterial infection. The JHR is significant both as a cause of morbidity and mortality and as an indication of the therapeutic efficacy of penicillin. The possible etiology of the JHR is discussed, and comparisons with the changes occurring in septic shock are made; a study of either condition facilitates the understanding of the other. Tumor necrosis factor is hypothesized to play a key role in both. Current treatment of the JHR consists of general clinical support. Specific measures such as oxpentifylline therapy may play a role in the future.