Abstract: A 65-year-old female presented with repeated nodules, plaques and pus on the left upper limb with pain for more than 7 years, and the right upper limb was involved for 1 year. The patient had a 3-year history of type 2 diabetes. Histopathology showed epidermal spinous hypertrophy with incomplete keratosis, full-layer dermal multi-focal granuloma with infiltration of lymphocytes and plasma cells, degeneration of collagen fibers and involvement of subcutaneous fat. The fungus culture showed white villous colonies. Under the microscope, the colonies appeared to be thick and unseparated mycelia with circular sporangia. Metagenomic examination revealed Mucor irregularis. The diagnosis of cutaneous mucormycosis caused by mucor irregularis was made.

Key words: Mucor irregularis, cutaneous mucormycosis, strain identification