S2145 The Great Imitator Hiding in Plain Sight

Abstract

Introduction: Lower gastrointestinal syphilis is a rare manifestation of early syphilis transmitted through anal contact. It usually occurs in men and transwomen who have sex with men. It can present with symptoms of proctitis including hematochezia, mucous discharge, and tenesmus, and can mimic inflammatory bowel disease (IBD). We present a case of intestinal syphilis in an HIV patient who presented with fevers and bloody diarrhea found to have intestinal spirochetosis. This case report adds to the importance of including STI colitis in the differential when presented with high-risk patients with lower gastrointestinal features. Case Description/Methods: A 32-year-old male with a history of untreated HIV, untreated hepatitis C, and IV drug use presented to the emergency department with a one-month history of worsening sharp and diffuse abdominal pain, subjective fevers, and blood-tinged mucoid bowel movements. He was diagnosed with rectal gonorrhea and chlamydia infection a few days prior to presentation and was treated with intramuscular ceftriaxone. He was discharged on doxycycline, which he failed to take. The patient’s social history is significant for being a sex worker and having sex with males. On physical exam, he was cachectic appearing with a diffusely tender abdomen. A rectal exam revealed palpable nodules and anal condylomas. He was treated with HAART and doxycycline for a presumed lymphogranuloma venereum infection. Computed Tomography (CT) of the abdomen pelvis showed an irregular and thick-walled rectum with perirectal soft-tissue stranding and necrotic nodes in the left perirectal region, the largest measuring 1.7 x 1.7 cm. Given continuous bloody bowel movements and a family history of colorectal cancer, a colonoscopy was obtained and showed scattered and patchy severe edema, erythema, and friability with shallow and deep rectal ulcerations. His labs revealed late latent syphilis infection (1:128 titer) and he was started on penicillin (PCN). Pathology of the colon later revealed intestinal syphilis as depicted in the Figure. Discussion: In recent years, there has been an increase in the number of reported cases of syphilis, especially in men and transwomen who have sex with men. Given this rare manifestation of syphilis, it is important to recognize and effectively treat to reduce patient morbidity and minimize community spread. Our case demonstrated the importance of maintaining a high level of suspicion for high-risk individuals presenting with lower gastrointestinal symptoms.Figure 1.: Right colon (Specimen A), left colon (Specimen B), and rectum (Specimen C).