EP907 - Syphilis Associated Colitis Mimicking Inflammatory Bowel Disease in an Immunocompromised HIV Positive Patient

Purpose/Background: Infectious colitis can clinically present similarly to inflammatory bowel disease. There must be a high index of suspicion for infectious etiologies of colitis, especially in immunocompromised populations. Here, we discuss a case of an immunocompromised young male with HIV who presented to the emergency department with symptoms of colitis and the successful diagnosis and treatment of his condition.

Methods/Interventions: 33-year-old male with a past medical history of HIV (not on HAART medication) presented to the emergency department with one-month hx of 10x daily bloody diarrhea, cramping abdominal pain and intermittent fevers. He had been homeless in the recent past and denied smoking, drinking or taking drugs. Patient was MSM. Patient had never had a colonoscopy. He had a prior exploratory laparotomy performed for right lower quadrant pain presumed to be appendicitis but appendectomy was not performed. He was febrile (38.8 C), tachycardic HR 115, and his abdominal exam was soft, with mild diffuse abdominal tenderness. His labs were significant for anemia Hgb 7.1, WBC 4.0. CT abdomen pelvis scan showed thick walled colon with reactive mesenteric lymph nodes and splenomegaly. In the ED, patient was started on IV Piperacillin/Tazobactam and stool culture panel was sent. Patient then underwent flexible sigmoidoscopy. Endoscopy revealed evidence of mild to moderate aphthous ulceration in the sigmoid colon without evidence of bleeding (Figure 1). Biopsies were taken to rule out ulcerative colitis but also sent for CMV, HSV and spirochete staining. Patient was initially presumed to have inflammatory bowel disease and started on IV solumedrol. However, given the fact that infectious etiology was higher on the differential, steroids were discontinued. Patient was started on doxycycline in addition to Piperacillin/Tazobactam for empiric chlamydia coverage.

Lab results revealed that patient was RPR positive with HIV viral load 51K, CD4 count of 28. Pathology results from biopsies showed colonic mucosa with numerous spirochetes, erosion, marked colitis consistent with intestinal spirochetosis (Figure 2). Patient was started on intramuscular penicillin for treatment of syphilis associated colitis.

Results/Outcomes: After the intramuscular penicillin was administered, patient had significant improvement in colitis symptoms. He underwent a spinal tap to rule out neurosyphilis. Patient was able to be discharged home with two more intramuscular penicillin doses that were administered in outpatient clinic on a weekly basis. Patient also started HAART therapy as an outpatient.

Conclusion/Discussion: It is important to always have a high index of suspicious for infectious etiologies of colitis in immunocompromised patients. Infectious etiologies, like LGV colitis secondary to chlamydia or syphilitic colitis, can mimic inflammatory bowel disease. These patients may be misdiagnosed and treated with high dose steroids if correct lab tests, biopsy stains, and stool cultures are not sent.

Figure 1
Images from flexible sigmoidoscopy showing shallow ulcerations in sigmoid colon

Figure 2
Histologic slides with Steiner stain identifying a large volume of spirochetes at the mucosal edge of the bowel.