Case Report: Primary cutaneous infection caused by Microascus trigonosporus

Microascus trigonosporus is an emerging opportunistic filamentous fungus most commonly causing invasive pulmonary infections in organ transplant recipients. Cutaneous infections caused by this organism are extremely rare worldwide. The article describes a case of a 67-year-old woman without transplant history who presented with progressive skin erythema and pustules lasting two months, unresponsive to topical halometasone treatment. Diagnosis was confirmed through microscopic examination, skin biopsy, fungal culture, and metagenomic next-generation sequencing (mNGS). The patient was treated sequentially with fluconazole for 2 weeks, followed by itraconazole for 8 weeks. The skin lesions completely resolved and no recurrence was observed during one-year follow-up without any adverse drug effects.