A patient with secondary syphilis following incomplete treatment of primary infection.

Syphilis is a bacterial infection caused by Treponema pallidum and is primarily transmitted via skin-to-skin or mucosal contact during sexual encounters, or through vertical transmission during pregnancy. Cases continue to rise globally across various demographic groups despite effective treatment and prevention interventions. We discuss the case of a 28-year-old cisgender man who presented with secondary syphilis 1 month after being inadequately treated for primary syphilis. Individuals can present with symptoms and signs of syphilis to clinicians of various subspecialties due to diverse clinical presentation. All health-care providers should be able to identify the common and less common manifestations of this infection, and adequate treatment and follow-up are crucial to preventing serious sequelae. Novel biomedical prevention interventions, such as doxycycline post-exposure prophylaxis, are on the horizon.