Abstract: Malignant syphilis (MS), also known as ulceronodular syphilis, is a rare manifestation of secondary syphilis. This paper reports two cases of HIV-negative malignant syphilis. Both patients presented with erythema, nodules, pustules, and crusting on the head and face, and developed Jarisch-Herxheimer reactions following treatment with benzathine penicillin, after which their rashes completely resolved. While most MS patients are HIV-positive, cases of HIV-negative malignant syphilis are relatively rare. This paper provides a literature review on the diagnosis, differential diagnosis, and treatment of malignant syphilis.

Key words: malignant syphilis, secondary syphilis, ulceronodular syphilis