Rare Case of Disseminated Histoplasmosis Presenting as Endogenous Histoplasma Capsulatum Endophthalmitis in an Immunocompetent Patient

This report presents a case of a 75-year-old man living in Arkansas, United States, who presented with subacute eye pain and severe vision loss in the left eye for 5 to 6 weeks and a history of 40-lb unintentional weight loss over the previous year. Exam revealed panuveitis initially suspicious for endogenous bacterial versus fungal endophthalmitis in the context of recent intravenous (IV) vitamin infusions. However, a systemic work-up revealed a positive serum and urine Histoplasma antigen, diagnostic for disseminated histoplasmosis. Vitreous cultures were negative, but pan-fungal polymerase chain reaction (PCR) testing returned positive for Histoplasma capsulatum , confirming a diagnosis of endogenous Histoplasma capsulatum endophthalmitis in the setting of disseminated histoplasmosis. Inflammation resolved after intravitreal injections of voriconazole and dexamethasone and initiation of systemic antifungal therapy, which included IV liposomal amphotericin B for 14 days and oral voriconazole planned for 1 year duration. Histoplasma capsulatum is a rare cause of endogenous fungal endophthalmitis and should be considered in cases of panuveitis, especially in the context of characteristic systemic symptoms of disseminated histoplasmosis and travel or residence in an endemic region.