Caught by a Medieval Disease: A Monoarthritis Revealing Syphilis

Syphilis is a sexually transmitted bacterial infection that first appeared in Europe in the 15th century, responsible for deadly epidemics before the discovery of penicillin. It typically progresses through three phases: primary syphilis, characterized by a syphilitic chancre that may appear on the genital area, anus, or oral cavity and can go unnoticed; secondary syphilis, which corresponds to the hematogenous dissemination of the treponema, leading to skin eruptions occurring in two waves, also known as "florid" phases, with the second wave being the most characteristic, involving papular lesions on the palms and soles. During this phase, there may also be lymphadenopathy, early neurosyphilis, and osteoarticular manifestations such as periostitis and arthritis [1,2,3]. Finally, tertiary syphilis, a historical form, is characterized by cardiac, vascular, and/or neuropsychiatric involvement. We report the case of a patient with risky sexual behavior who presented with an oral ulceration possibly corresponding to an oral syphilitic chancre in the primary phase. The patient did not seek medical attention at that time and developed secondary syphilis with joint involvement two months later. This article aims to remind that syphilis should not be excluded when faced with the combination of oral ulceration and arthritis, alongside chronic inflammatory bowel diseases, Behçet's disease, and lupus. The infection has to be confirmed in the joint aspiration either by isolating the treponema or by finding the pathogen’s DNA or simply by TPHA and VDRL technique ; as for the syphilitic arthritis should be treated as a secondary siphilis.