Primary cutaneous mucormycosis masquerading as pyoderma gangrenosum

Sir, Mucormycosis refers to opportunistic infection caused by fungi of the class Zygomycetes and the order Mucorales. Most reported cases of mucormycosis occur in immunocompromised hosts. Host risk factors include diabetes mellitus, neutropenia, sustained immunosuppressive therapy, chronic prednisolone use, iron chelation therapy, broad‐spectrum antibiotic use, severe malnutrition, and primary breakdown in the integrity of the cutaneous barrier caused by trauma, surgical wounds, needle‐stick injuries or burns. To our knowledge, only 19 cases of Rhizomucor infection have been described in the literature, with only two cases of primary cutaneous involvement.1 Cutaneous disease may occur from primary inoculation or as a result of disseminated disease. The clinical presentation will be quite different for these two disease processes. Growth of the fungus in a pre‐existing lesion produces an acute inflammatory response with pus, abscess formation, tissue swelling and necrosis. The lesions may appear red and indurated but often progress to form black eschars. Necrotic tissue may slough off and produce large ulcers. Primary cutaneous disease may be very invasive locally, involving not only the cutaneous tissue but also the fat, muscle and fascial layers beneath. Cutaneous disease arising from disseminated disease, in comparison with wound zygomycosis, usually presents as nodular subcutaneous lesions which may ulcerate.2 We present a third case of primary cutaneous involvement by Rhizomucor.