A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
We report 2 cases of chronic subcutaneous infection in immunocompetent persons caused by Fomitiporella spp. basidiomycetes. Both patients recovered after surgical excision without antifungal therapy. We confirmed the cause of infection using broad-range fungal PCR from formalin-fixed tissue, highlighting the value of molecular diagnostics for detecting rare environmental fungi.
Although systemic fungal infections are most often associated with immunocompromised patients, several well-described fungal diseases, such as chromoblastomycosis, mycetoma, and sporotrichosis, cause localized skin and subcutaneous infections in immunocompetent persons. The range of environmental fungi known to cause localized infections in immunocompetent persons is expanding ( 1 ). Such infections often follow a prolonged, indolent course and remain confined to specific organs, such as the skin and subcutaneous tissues. Subcutaneous fungal infections involve deeper layers of the skin and underlying tissues and usually result from infection by low-virulence organisms ( 2 ). Acquisition of fungi involved in localized infections can occur via environmental exposure, inhalation followed by localized disease, or traumatic inoculation ( 1 – 3 ). Traumatic inoculation is the most common portal of entry in cutaneous and subcutaneous fungal infections, frequently involving exposure to contaminated vegetation, wood, or soil.
Among the diverse fungi that cause opportunistic or localized disease, many members of the phylum Basidiomycota (basidiomycetes), including yeasts such as Cryptococcus and Malassezia as well as filamentous fungi, are environmental organisms that are rarely implicated in human disease. Filamentous basidiomycetes present a particular diagnostic challenge to clinical laboratories because they often fail to sporulate in culture; they might be mistakenly classified within the broad category of hyaline molds because they are often indistinguishable by conventional morphologic methods ( 4 , 5 ). Since the early 2000s, molecular techniques have increasingly been used to improve recognition and classification of such organisms ( 6 ); specific filamentous basidiomycetes have been implicated in hypersensitivity syndromes, chronic cough, allergic bronchopulmonary disease, sinusitis, and, rarely, invasive infections ( 5 , 7 , 8 ). However, the pathogenic potential for many genera within Basidiomycota remains unknown.
Fomitiporella is a genus of filamentous basidiomycetes comprising wood-decaying fungi ( 9 ) with no well-established role in human disease. Here, we report 2 cases of localized Fomitiporella infection in immunocompetent patients in the United States, both diagnosed using broad-range fungal PCR.
Case 1 was in a 46-year-old man in North Dakota, USA, who immigrated from Liberia in 2012. When he sought care in 2025, he had a 2-year history of localized pain, discomfort, and restricted movement over his right olecranon bursa. He reported no injury to the area, fever, night sweats, weight loss, or respiratory symptoms. His medical history was unremarkable, and he was taking no prescription medications. Magnetic resonance i…