Atypical Presentation of Secondary Syphilis

Syphilis is caused by Treponema pallidum and clinically presents with variable mucocutaneous features. The clinical features of secondary syphilis can be macular, maculopapular, follicular, papulosquamous, or pustular, as well as erythema multiforme (EM)–like targetoid lesions. We describe a patient with secondary syphilis presenting as a diffuse, large, annular patch.