Syphilitic proctitis mimicking ulcerative colitis in a person living with HIV

Syphilitic proctitis is a rare presentation of syphilis that can mimic IBD, posing a diagnostic challenge, especially in immunocompromised patients. We report the case of a 28-year-old transgender woman with a past medical history of ulcerative colitis, HIV, and syphilis, initially misdiagnosed with ulcerative colitis. Sigmoidoscopy showed a rectal ulcer; histology and positive syphilis serologies confirmed syphilitic proctitis. This case highlights the need to consider infectious causes in atypical or treatment-resistant proctitis, emphasising the value of a thorough history and targeted testing.