Disseminated histoplasmosis diagnosed by cross-reactivity with the Aspergillus galactomannan antigen in an HIV-positive patient.

Invasive histoplasmosis is the most common AIDS-defining event in endemic regions such as South America. In non-endemic regions, less familiar to the diagnosis, invasive histoplasmosis can be mistakenly diagnosed as miliary tuberculosis leading to a high mortality rate. Here we present the case of an invasive histoplasmosis mistakenly diagnosed as tuberculosis. The diagnosis of histoplasmosis was considered later on, in light of patient's clinical deterioration and positive Aspergillus galactomannan antigens. This case highlights the importance of considering other opportunistic infections when facing a culture-negative miliary tuberculosis without clinical improvement despite anti-tuberculosis therapy. It also draws our attention to the tools available in non-endemic regions that can be helpful in the diagnosis of invasive histoplasmosis.