First case of human chromoblastomycosis caused by Alternaria alternata in Brazil: a case report

Chromoblastomycosis (CBM) is a neglected, chronic subcutaneous disease with progressive development, caused by a variety of melanized fungal species. The main etiological agent of CBM in Brazil and throughout the world is Fonsecaea pedrosoi. However, there is a significant knowledge gap regarding the relationship between other CBM-causing species and the host, which needs to be further investigated. We report a case of CBM in which Alternaria alternata was identified as the etiological agent in a patient with no history of immunodeficiency or other medical conditions that impair the immune response. In particular, the patient’s skin exhibited a predominant T-regulatory immune response, marked by IL-10 production, which may have contributed to the persistence of the fungus in the tissue. This is the first report identifying Alternaria alternata as the etiological agent of CBM in Brazil.