Hand surgeon diagnosis and management of cutaneous infection with Purpureocillium lilacinium of the upper extremity: A mimicker of necrotizing fasciitis

Purpureocillium lilacinum is a filamentous fungus commonly found in soil that has been recognized as an opportunistic pathogen. Cutaneous infections with Purpureocillium lilacinum are relatively rare, and they usually occur in individuals with some predisposing factors such as minor trauma or pre-existing skin conditions. Infections in immunocompetent individuals are unexpected due to the fungus’s typically low pathogenicity and the robust immune response of healthy individuals. In immunocompetent hosts, the skin serves as an effective barrier against many fungal infections. While cases of cutaneous infections in immunocompetent hosts have been documented, they are considered rare outliers. Presented is the case of a 93-year-old male who presented to the emergency department with a 10-day history of progressive, painful left upper extremity erythema and swelling. The patient had aggressive progression of hemorrhagic bullae requiring surgical debridement. While the patient’s presentation was originally thought to be consistent with necrotizing fasciitis, only cutaneous necrosis was encountered, and the patient was ultimately diagnosed with a superficial P. lilacinum infection. The failure of treatment leading to death in the described case could be attributed to a combination of factors including intrinsic resistance of the fungus, delayed diagnosis, underlying health conditions, antifungal susceptibility variations, fungal persistence, and immunosuppressive factors.