Sporotrichosis Caused by Sporothrix mexicana, Portugal

To the Editor: Sporotrichosis is a subcutaneous fungal infection present worldwide that is caused by traumatic inoculation or inhalation of spores of the dimorphic fungus Sporothrix schenckii complex (1–3). However, molecular studies have shown that the S. schenckii complex constitutes several cryptic infectious species demonstrated 3 major clades grouped into 6 putative phylogenetic species. The natural habitats of these species are soil and plants. The species showed distinct pathologic behavior, antifungal responses, and phenotypes, which suggests that optimal clinical treatment may depend on the taxon involved in the sporotrichosis (1). Human infections have been reported primarily from the Americas, including Latin America (3,5). Asia and Australia are also regions where infections are endemic (6). Although infections are rare in Europe, a case of human infection (7) and a case of an animal infection (8) have been described in southern Italy. We report a case of human sporotrichosis in which S. mexicana was isolated from a patient in Portugal. A 34-year-old man sought care at a podiatry clinic in Vila Nova de Famalicão, Portugal, in 2009 for multiple polymorphous eruptions and ulcers on both feet. There was no obvious cause of the disease. Although the patient had traveled to Malaysia in 2003 and had worn open footwear every day, he did not recall receiving a skin wound. In 2004 in Portugal, subcutaneous nodules appeared in both feet, became ulcerated, and spontaneously healed. By 2005, more severe lesions had appeared and became a chronic infection in both feet and lower limbs. The symptoms were diagnosed erroneously as dyshidrotic eczema, and treatment with topical corticosteroids was unsuccessful. Several skin fragments of the lesions were submitted for mycological assessment. Fungi were not found on potassium hydroxide slides of all samples. Filamentous fungal colonies were observed after 7 days of culture on Sabouraud dextrose agar slopes at 25°C. The fungus had hyaline septate hyphae, with hyaline and dematiaceous conidia compatible with Sporothrix spp. The isolate was accessed and preserved in the Micoteca da Universidade do Minho (MUM, Braga, Portugal) fungal culture collection and given the accession code MUM 11.02. The macroscopic features and sporulation were analyzed by using cornmeal and potato dextrose agars. Clusters of intercalary or terminal conidia were formed by sympodial growth from differentiated conidiophores on both media. Sympodial conidia were hyaline or slightly pigmented. Sessile conidia were predominantly subglobose, obovoidal or ellipsoidal, and 3.35 ± 0.41 μm long by 2.30 ± 0.32 …