Histoplasmosis is the most commonly described endemic mycosis in Spain. Although Histoplasma capsulatum is found mainly on the American and African continents, it is now distributed worldwide. Spain has seen a notable increase in the number of reported cases in recent decades, possibly because of the rise in travel abroad for either business or leisure. It should also be noted that up to a third of immigrants residing in Spain come from countries in the Americas where endemic mycoses are common.

Histoplasmosis is classically associated with high mortality in patients with immunosuppression caused by human immunodeficiency virus (HIV) infection. In this issue of the journal, Gómez-Santana and colleagues1 report 3 cases of disseminated histoplasmosis in patients with immune compromise unrelated to HIV. Because they were cases of American histoplasmosis, caused by H capsulatum var. capsulatum, pulmonary signs and polymorphic skin involvement (eg, papules, nodules, cutaneous-mucous ulcers) predominated. Thus, manifestations at any stage of this variant of the disease can mimic tuberculosis.

This emerging mycosis affects travelers and immigrants, and given that more and more patients are prescribed immunosuppressive treatments (including biological therapies for autoimmune diseases2) every year, a high level of suspicion is warranted in patients coming from areas where H capsulatum is endemic. Diagnostic delays that could further worsen the prognosis must be avoided.