Syphilis proctitis: an uncommon presentation of Treponema pallidum mimicking malignancy

Syphilis proctitis is a rare manifestation of syphilis, a bacterial sexually transmitted infection caused by Treponema pallidum Syphilis proctitis can mimic other conditions including inflammatory bowel disease, lymphogranuloma venereum and anal or rectal cancer. We describe a case of a man in his 60s presenting with a variety of anorectal symptoms, where the definitive diagnosis was challenging, leading to diagnostic delay and a protracted symptom course due to difficulties in identifying and treating this rare manifestation of syphilis. After extensive investigations and various treatments, a diagnosis of syphilis was made, and treatment resulted in complete resolution of symptoms within 1 month. This case highlights several issues for clinicians to consider during the diagnostic workup and management of patients presenting with anal symptoms and, in the context of a global upsurge in syphilis, serves as a reminder to remain vigilant to unusual and rare manifestations of infectious syphilis.