S2236 Disseminating Histoplasmosis Masquerading as an Inflammatory Bowel Disease Flare

Abstract

INTRODUCTION: Crohn’s disease typically presents with abdominal pain, diarrhea, fatigue, and weight loss. Disease activity can be graded from mild to severe with the aid of various indices such as the Crohn’s Disease Activity Index (CDAI) and the Harvey-Bradshaw Index (HBI). Mild Crohn’s disease is typically managed with “step-up” therapy in which patients are initially trialed on a steroid taper. Mild to severe Crohn’s is managed with a “top-down” approach in which more aggressive medications such as biologics/immunomodulators are initiated with the goal of inducing remission. These medications are effective however they are also inherently immunosuppressive agents which puts patients at risk for opportunistic infection. In this case report, we examine the clinical course of a young female on chronic immunosuppression for Crohn’s disease who suffered life-threatening bowel perforation and pericardial effusion secondary to disseminated histoplasmosis. CASE DESCRIPTION/METHODS: A 32-year-old female with Crohn’s disease on adalimumab and oral prednisone was admitted to MGUH from GI clinic with tachycardia, fevers, nausea and abdominal pain concerning for Crohn’s disease flare. Two days after admission, she was taken to the operating room for the discovery of jejunal perforation. Two weeks later, she returned to OR for recurrence of bowel perforation and received a small bowel resection, ileocecectomy, and end ileostomy. Review of pathology was indicative of Crohn's disease in the jejunum and disseminated histoplasmosis in the ileocecal region. Ambisome was initiated on discovery of these findings. Tachycardia persisted despite fluid resuscitation and echocardiogram revealed pericardial effusion and RV diastolic collapse threatening impending cardiac tamponade. Pericardial fluid revealed histoplasmosis antigen confirming the diagnosis of disseminated histoplasmosis. DISCUSSION: Histoplasmosis Capsulatum is the most prevalent endemic mycosis in the United States. Macrophage and T- Cell immunity plays a crucial role in host defense against the organism hence it is the most common fungal infection seen in patients treated with TNF-alpha inhibitors. Patients with IBD presenting with an acute abdomen can present a diagnostic challenge in distinguishing whether underlying pathology is secondary to uncontrolled inflammatory disease or immunosuppressive therapy. This case reinforces that immunosuppressed patients and those on biologics should always have opportunistic infection ruled out in life threatening illness.Figure 1.: CT Abdomen/Pelvis with IV contrast demonstrates long segment jejunal enteritis and small bowel perforation given numerous loculated pockets of fluid and air within the small bowel mesentery, as well as free air within the anterior peritoneal cavity and free fluid dependently in the pelvis.Figure 2.: CT Abdomen/Pelvis without IV contrast demonstrates intestinal perforation with increasing pneumoperitoneum and ascites. Multiple small foci of free air adjacent to the ileum were also noted that indicate possible site of perforation, but this is hard to verify without the presence of intravenous contrast.Figure 3.: CT Chest without IV contrast demonstrates a moderately sized pericardial effusion, slightly increased compared to prior studies. The imaging study also indicated moderate bilateral pleural effusions with associated compressive atelectasis.