S1823 Gastrointestinal Histoplasmosis, a Rare and Devastating Disease

Abstract

INTRODUCTION: Disseminated histoplasmosis is a devastating disease that affects the immunocompromised patient population. Gastrointestinal histoplasmosis is a rare disease that has been well described in literature. Here we present a case of severely ulcerated Histoplasma colitis. CASE DESCRIPTION/METHODS: A 61-year-old female with a past medical history of systemic lupus erythematosus, dual lung transplant secondary to idiopathic pulmonary fibrosis, and chronic immunosuppression on Tacrolimus presented to the hospital with diarrhea and symptomatic anemia. Notably, the patient became more anemic over the last one year. She denied overt bleeding, such as melena, hematemesis, or hematochezia. She reported that for the last three months, she had watery diarrhea, having about three episodes daily. Stool studies were sent, which were all negative. On admission, she was febrile to 102F. Gastroenterology was consulted, and a colonoscopy was performed which revealed a single ulcer at the ileocecal valve and rectum, with multiple ulcers in the descending colon, in the transverse colon and in the ascending colon. Biopsies were taken. A special stain for Gomori's Methenamine Silver (GMS) stain was positive for yeast organisms, morphologically compatible with Histoplasma capsulatum. The patient was started on a 14-day course of IV Amphotericin B given the extent of tissue invasion. She was transitioned to Itraconazole on discharge. Overall, she had clinical improvement with treatment. DISCUSSION: Histoplasmosis is a disease caused by Histoplasma capsulatum, a fungus that is endemic to the central and eastern United States. Most disease cases are mild and asymptomatic. When the disease is symptomatic, it typically manifests as a pulmonary infection. Gastrointestinal histoplasmosis occurs in approximately 3–12% of all cases. Untreated, mortality can be as high as 80%. In conclusion, it is essential to keep histoplasmosis on the differential in immunocompromised patients who present with fever and diarrhea.Figure 1.: Ileo-cecal valve and cecal ulcers.Figure 2.: Transverse Colon and Descending Colon-Ulcers.Figure 3.: Colon Biopsy Positive for Gomori's Methenamine Silver (GMS) stain.