A Case of Cutaneous Purpureocillium lilacinum Infection Looking like Psoriasis

Purpureocillium lilacinum is a saprophytic fungus with a ubiquitous environmental distribution, and it can be detected in soil samples and decaying materials worldwide. It has been reported as an emerging pathogen in both immunocompromised and immunocompetent patients, showing various cutaneous presentations. Herein, we report a case of a patient with a localized cutaneous P. lilacinum infection, which resembles the skin lesions of psoriasis. A 72-year-old female was presented with a peripherally spreading, well-demarcated, asymptomatic, scaly, erythematous patch on her forehead for several months. Histopathological examination showed pinkish septated fungal elements and mixed inflammatory and granulomatous infiltrates in the dermis. Furthermore, a fungal culture on potato dextrose agar showed gray, velvety colonies with light yellow background after being subcultured. Phialides with chains of oval conidia were observed on lactophenol cotton blue staining. The ITS region of rRNA gene sequence obtained from the colony was identical to that of Purpureocillium lilacinum. The lesion was resolved with oral itraconazole (200 mg/day) after four months of treatment.