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causes of bloody diarrhea in these patients. 1 Sometimes, coinfection with two different or- ganisms can cause severe diarrhea, as in our patient. Hence, we need to be very cautious. Histoplasma is a common, opportunistic infection in HIV/AIDS patients living in endemic areas. Histoplasmosis is caused by an invasive fungus called Histoplasma capsulatum, which is endemic to certain parts of U.S. including Mis- sissippi, Ohio, and the St. Lawrence River Val- ley. The fungus is found abundant as spores in the soil that is contaminated by bird feces. The disease is transmitted upon inhalation of the spores, which convert into yeast form. They are engulfed by macrophages, where they multiply and spread throughout the body via reticulo- nodular system. In immunocompetent patients, infection is usually self-limited and most often time goes unnoticed. However, patients who are immunocompromised can have serious illness. It can present either with isolated pulmonary infection or disseminated disease with multi- organ involvement (skin, GI tract, liver, spleen, meninges, kidneys, adrenal glands, etc.). Histoplasma can be identified in the GI tract of 70-90% patients with disseminated disease, but only 3-12% of those are symptomatic. 2,3 It usually presents with non-specific symptoms like fever, night sweats, nausea, vomiting, diar- rhea, abdominal pain, hematochezia, melena, 4 and oropharyngeal ulcerations. Sometimes it can present as a mass leading to intestinal ob- struction. Lesions occur anywhere in the GI tract from mouth to anus but are more common in the terminal ileum due to abundance of lymphoid tissue. 5,6 Typical endoscopic lesions are patchy or continuous superficial-deep ulcerations, ac- companied by diffuse mucosal erythema, and rarely as polypoid masses causing obstruction or annular constricting ulcers leading to strictures. 6 These findings can often be misdiagnosed for malignancy or IBD; hence, a careful evaluation and high index of suspicion is warranted. Mouth ulcers are usually very painful and can mimic malignancy by their appearance. Antigen detection in tissues samples (blood, urine, BAL) is useful for diagnosis of dissemi- nated histoplasmosis. It is positive in >90% patients with disseminated disease. However, it may be falsely negative in patients with local- ized GI involvement. Hence, biopsy is warranted Image 2a: Photomicrograph showing active colitis with ulcerated colonic mucosa; 2b: Extensive accumulation of macrophages within lamina propria; 2c: Image showing positive PAS stain; 2d: GMS stain highlights accumulation of numerous intracellular 2-4 um fungal spores consistent with Histoplasma capsulatum. for appropriate and accurate diagnosis. Pathol- ogy suggests abundant inflammatory infiltrate and multiple intracellular, ovoid-spherical, nar- row-based budding yeast cells, visualized bet- ter with methenamine silver stain. Treatment is not indicated for mild pulmonary illness or self- limiting illness (symptoms lasting for <1 month). However, all disseminated histoplasmosis, acute pulmonary histoplasmosis with symptoms last- ing for > one month, or those who have hypoxia, need to be treated. Treatment is divided into two different phases: induction treatment and lifelong suppressive therapy. Patients with less severe disease may be treated with itraconazole, but amphotericin-B is merited in moderate-se- vere disease. 4 Length of induction therapy varies depending on the severity of illness and is usu- ally in weeks. As patients have a high chance of relapse, lifelong suppressive therapy with either itraconazole or fluconazole is warranted. Trials have shown better remission with itraconazole compared to fluconazole. Some people use se- rum antigen levels to monitor response to ther- apy. Disseminated histoplasmosis carries high mortality (~80%), hence early identification and treatment is necessary. CONCLUSION Coinfection with common nosocomial bugs like Clostridium difficile may masquerade the underlying histoplasmosis, hence a high index of suspicion is essential, especially in immuno- compromised patients. Due to a lack of specific signs and symptoms for GI histoplasmosis, this entity may be missed many times. Any patient with unexplained GI symptoms in HIV/AIDS pa- tients should be evaluated for histoplasmosis. 7 Disseminated histoplasmosis carries high mor- tality up to 80%, hence early identification and treatment is necessary. Treatment decreases mortality to less than 25%. REFERENCES 1. Chalasani N, Wilcox CM. Etiology and out- come of lower gastrointestinal bleeding in patients with AIDS. Am J Gastroenterology. 1998 Feb; 93(2): 175-8. 2. Goodwin RA, Shapiro JL, Thurman GH, et al. Disseminated histoplasmosis: clinical and pathologic correlations; Medicine (Balti- more) 1980; 59(1): 1. 3. Kahi CJ, Wheat LJ, Allen SD et al. Gastroin- testinal histoplasmosis. Am J Gastroenterol- ogy. 2005 Jan; 100(1): 220-31. 4. Wheat LJ, Sarosi G, McKinsey D et al. Prac- tice guidelines for the management of pa- tients with histoplasmosis. Clin Infect Dis. 2000; 30(4): 688–695. (4) 5. Yang B, Lu L, Li D et al. Colonic involvement in disseminated histoplasmosis of an immu- nocompetent adult: case report and litera- ture review. BMC Infect Dis. 2013; 13: 143. 6. Spinner MA, Paulin HN, Wester CW et al. Duodenal Histoplasmosis Presenting with Upper Gastrointestinal Bleeding in an AIDS Patient. Case Reports in Gastrointestinal Medicine Volume 2012, Article ID 515872, 4 pages. 7. Graham BD, McKinsey DS, Driks MR et al. Colonic Histoplasmosis in acquired immuno- deficiency syndrome. Report of two cases. Dis Colon Rectum. 1991 Feb; 34 (2): 185- 90. NUMBER 12 JUNE 2019 • 275