Byung K.. Lee, MD, Hillary Smalley, DO, Brett Sadowski, MD Naval Medical Center San Diego, San Diego, CA
Introduction: We present a case of a patient with known severe Hidradenitis Suppurativa (HS), found to have intriguing endoscopic and imaging findings at the time of diagnosing fistulizing perianal Crohn’s Disease (CD).
Case Description/Methods: A 40-year-old female with a history significant for uveitis, pyoderma gangrenosum (PG) and Hurley Stage III HS on Adalimumab presented with one week of painful hematochezia in the setting of HS flare. She had one prior episode five years ago with a normal colonoscopy; however, with her symptoms, known history of HS and extra-intestinal manifestations of uveitis and PG, she underwent a repeat colonoscopy with high suspicion for CD. External exam revealed several scattered open wounds centered around the perineum. Upon insertion of the colonoscope 10 cm into the anal verge, two lumens were visualized within the rectum bisected by a bridge of abnormal appearing tissue (Image 1A). The mucosa of the second lumen appeared non-colonic with blood obscuring the view of the distal most extent. Biopsies were obtained from the abnormal appearing tissue bisecting the two lumens. The remainder of the colonic mucosa was normal up to the terminal ileum. Pathology showed ulcerated active colitis. Subsequent computed tomography (CT) abdomen showed a 3.7 cm rightward blind end pouch of the lower rectum extending from the anal verge without intra-abdominal fistulous connection to other loops of bowel or vagina (Image 1B) though there was evidence of a complex trans-sphincteric perianal fistula. Overall findings were consistent with fistulizing perianal CD and patient was transitioned to Infliximab. On follow up after six weeks of Infliximab, patient had noticeable symptom improvement but had yet to reach clinical remission.
Discussion: This patient had a primary diagnosis of severe HS on Adalimumab with a later diagnosis of concomitant fistulizing CD despite being on biological therapy. This case highlights the challenging relationship between fistulizing CD and HS in perianal disease in the absence of traditional endoscopic, pathologic and imaging findings. Multi-modal evaluation should be pursued for accurate diagnosis. Treatment was geared towards targeting both HS and CD. Secukinumab, while used in HS, is not approved in the treatment for CD. Additionally, efficacy of Ustekinumab in fistulizing disease was limited. As the patient failed Adalimumab therapy, biologic therapy was limited to Infliximab.
Figure: Image 1: (A) Endoscopic view of the bisecting lumen in the rectum. Colonic lumen is seen in the 10 o’clock position (red star) and the false lumen to the right with a visible large blood blot. (B) Coronal view of CT Abdomen showing the blind ending pouch (red arrow) in the rectum correlating to endoscopic findings.
Disclosures:
Byung Lee indicated no relevant financial relationships.
Hillary Smalley indicated no relevant financial relationships.
Brett Sadowski indicated no relevant financial relationships.
Byung K.. Lee, MD, Hillary Smalley, DO, Brett Sadowski, MD. P4429 - Fork in the Road: Fistulizing Perianal Crohn’s Disease and Hidradenitis Suppurativa, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.
