Disseminated Histoplasmosis Diagnosed by "Touch Prep".

Disseminated histoplasmosis is a rare but serious complication of infection with the dimorphic fungus Histoplasma capsulatum. We report a case of disseminated histoplasmosis with cutaneous involvement diagnosed by touch wet preparation and confirmed with histopathology and culture. "Touch prep" performed from a lesional punch biopsy, prepared with Wright-Giemsa followed by chlorazol black containing KOH, revealed abundant yeast organisms localized within multinucleated giant cells, and a rapid diagnosis of disseminated histoplasmosis with cutaneous involvement was achieved. This report demonstrates the utility of wet prep techniques as an invaluable and rapid beside diagnostic tool in the setting of cutaneous histoplasmosis. In addition, we compare the distinguishing histopathologic features of the infectious organisms within the differential diagnosis of parasitized histiocytes.