Histoplasma capsulatum var. duboisii: A Case of Histoplasmosis 50 Years After the Exposure.

Histoplasmosis is a mycotic infection caused by Histoplasma capsulatum, a thermally dimorphic organism that presents two pathological variants in humans: H. capsulatum var. capsulatum and H. capsulatum var. duboisii. The latter is restricted to Africa, where both variants may coexist. H. capsulatum var. duboisii mainly affects the skin, subcutaneous tissues, and bone, with rare dissemination. Infections can exhibit prolonged latency, reactivating decades after exposure. This report describes a rare case of histoplasmosis due to H. capsulatum var. duboisii, including its laboratory approaches, in a 73-year-old immunocompetent male patient from Portugal who served in Angola in the 1970s. The patient presented with an exophytic gingival lesion that progressed over three months and a lesion on the left wrist joint. This case emphasizes the vital role of microbiological approaches in diagnosing histoplasmosis and highlights the need to consider it in individuals who have been in endemic regions, regardless of the temporal gap since exposure.