Jarisch-Herxheimer reaction in complement-depleted rabbits. Histological and immunofluorescence studies of early cutaneous lesions.

The possible role of complement in the pathogenesis of the Jarisch-Herxheimer reaction was assessed in cutaneous syphilitic lesions in two groups of rabbits treated with penicillin; in one group complement was depleted before penicillin therapy. Serial biopsy specimens were similar histologically in both groups. The activation of the complement pathways did not seem to play a role in the pathogenesis of early cutaneous syphilitic lesions in rabbits during the Jarisch-Herxheimer reaction.