Case Report: Disseminated Histoplasmosis of the Tongue Presenting Decades after Exposure in Latin America

Abstract

Histoplasma capsulatum is a thermally dimorphic fungal pathogen endemic to the Mississippi and Ohio River Valley regions of North America and much of Central and South America. As an opportunistic pathogen, H. capsulatum can assume a latent infection that can be reactivated by immunocompromised states or immunosuppressive therapy. We report a case of a 72-year-old man who lived in rural regions of Panama, Honduras, and Nicaragua while serving in the U.S. military from 1987 to 1991. Three decades after his initial exposure, the patient presented for evaluation of a painful tongue ulcer that originated when he began taking adalimumab to manage his psoriatic arthritis 2 years earlier. Tissue scraping of the tongue ulcer grew a whitish to cream-colored, fluffy-textured mold that was morphologically identified as Histoplasma. Molecular analysis of the fungus confirmed H. capsulatum var. Latin American group A, known as Histoplasma suramericanum. Further testing showed a positive H. capsulatum antibody mycelial complement fixation, and a 1-cm calcified nodule in the lower lobe of the left lung on computed tomography. Here, we highlight the importance of recognizing disseminated histoplasmosis in patients with exposure to endemic regions before initiating immunosuppressive therapy.