Progressive Severe Hemophagocytic Syndrome due to Disseminated Histoplasmosis in a Patient with HIV-1 Infection

Histoplasmosis is caused by Histoplasma capsulatum and is prevalent in areas of the world where H. capsulatum is endemic. We herein report a patient diagnosed with human immunodeficiency virus-1 (HIV-1) who developed histoplasmosis from a non-H. capsulatum endemic area who experienced severe hemophagocytic syndrome due to a delayed diagnosis. The patient's symptoms emerged four years after residing in regions with a high histoplasmosis prevalence. The unrestricted administration of antifungal medication for oral candidiasis delayed the diagnosis because it improved the patient's condition. This case underscores the importance of prudent antifungal drug use in undiagnosed disseminated conditions and evaluating the travel history going back several years to facilitate a diagnosis.