Histoplasmosis capsulatum as a cause of lower gastrointestinal bleeding in common variable immunodeficiency.

Infection with Histoplasma capsulatum is the most common systemic fungal infection in the United States, but symptomatic gastrointestinal disease is rare. Gastrointestinal involvement is seen in patients with an established immunosuppressed state that predates any infection. We report a patient presenting with gastrointestinal bleeding ultimately diagnosed with disseminated histoplasmosis. Work-up led to the diagnosis of common variable immunodeficiency, a diagnosis not previously described as associated with gastrointestinal histoplasmosis. Resolution of the colonic ulcer was documented after appropriate antifungal therapy, underscoring the importance of including this infectious process in the differential of a patient without other risk factors for colonic ulceration.