Cutaneous and Lymphangitic Infection Caused by Purpureocillium lilacinum in Immunocompromised Patients: A Case Report with a Narrative Review of the Literature

Background: Purpureocillium lilacinum (P. lilacinum) is an emerging filamentous fungus known to cause opportunistic infections, particularly in immunocompromised patients. Formerly known as Paecilomyces lilacinus, this pathogen is widespread in the environment and can lead to a range of infections, from superficial skin lesions to invasive diseases. This article presents a case of deep cutaneous hyalohyphomycosis caused by P. lilacinum in a liver transplant patient, followed by a review of the literature focusing on new antifungal agents. Methods: We reported a brief case description followed by a narrative review of the literature regarding P. lilacinum cutaneous and lymphangitic infections in immunocompromised patients. Results: We conducted a review of the literature over the past 20 years, focusing on the clinical features, diagnostic challenges, and therapeutic outcomes of cutaneous and lymphangitic P. lilacinum infections in immunocompromised hosts. Conclusions: This review highlights the critical importance of early diagnosis through the analysis of biopsy samples using standard microbiological and histological techniques, complemented by innovative molecular biology methods. We also emphasise the role of appropriate antifungal treatment, despite the absence of an established standard of care, particularly in high-risk patients. Furthermore, we review and discuss the current lack of a standardised therapeutic regimen and the potential of novel antifungal agents as promising treatment options for P. lilacinum infections.