1480 Colonic Spirochetosis Causing Ulcerative Proctitis

Abstract

INTRODUCTION: Intestinal spirochetosis is a rare infectious diarrheal illness. Here we present a case of colonic spirochetosis initially diagnosed and treated as ulcerative proctitis. CASE DESCRIPTION/METHODS: A 57-year-old male presented to the office with 2 months of diarrhea occurring over 10 times per day with urgency and bleeding. The patient had an unremarkable past medical and family history. On social history, he practiced high risk sexual behavior with unprotected anal intercourse. Initial work-up showed mild elevation of ESR/CRP and an elevated calprotectin. Colonoscopy revealed ulcerative proctitis extending to 15 cm with normal colonic mucosa proximally. Rectal biopsies showed moderately active chronic colitis, remaining biopsies of colon were normal. He was started on mesalamine with improvement and subsequent sigmoidoscopy showed remission. Eight weeks later the patient presented to the ED with blurry vision. He was seen by ophthalmology who identified left optic nerve edema. An RPR was sent and resulted with a titer of 1:1024. He was referred to Infectious Disease with high suspicion for ocular syphilis and completed 14 days of IV penicillin G. Lumbar puncture showed no neurologic involvement. His RPR titers downtrended and visual changes improved. One month later, the patient developed large volume loose stools. Again stool studies were negative. Pathology was contacted to conduct repeat histochemical stains on earlier specimens, which showed spirochetes in the colonic mucosa. He was given metronidazole for 14 days for intestinal spirochetosis with improvement. With suspicion that proctitis may have originally been infectious the mesalamine therapy was weaned. DISCUSSION: Clinical manifestations of colonic spirochetosis can vary from asymptomatic to watery diarrhea. Rectal ulcerations are an uncommon presentation of primary syphilitic infection when compared to other mucosal sites. A literature review revealed a range of endoscopic findings from normal mucosa to erythema, friability, and polypoid lesions. To our knowledge the development of multiple ulcers has not been reported. It is necessary to maintain a high clinical suspicion because the diagnosis can be missed on a histologic level without appropriate additional staining. Given the increasing prevalence of syphilis, this case highlights the importance of collecting a thorough sexual history as to not delay the diagnosis and prevent the progression of disease, especially since early disease can frequently be asymptomatic.