Mucormycosis is a rare invasive fungal infection with exceedingly high mortality and few therapeutic options. The disease is caused by Mucorales, which is a large group of species within the order of zygomycetes.
Mucorales are widespread in the environment and generally affect severely compromised individuals. Persons at risk include patients with organ transplants, hematologic malignancies, diabetes mellitus or renal failure. Mucorales can also infect people with normal immunity who underwent subcutaneous traumatic inoculation.
Invasive mucormycosis can result in rhino-orbitalcerebral, pulmonary, gastrointestinal, cutaneous, widely disseminated, and miscellaneous infection. The hallmark of disease is tissue necrosis resulting from angioinvasion and subsequent thrombosis; black, necrotic eschars are common in affected tissues. In many cases, the disease progresses rapidly and may result in death unless underlying risk factors are corrected and appropriate antifungal therapy and surgical excision are initiated. The most prevalent etiological agents of mucormycosis in humans are Rhizopus oryzae, Mucor racemosus, Rhizomucor pusillis, Lichtheimia corymbifera and Cunninghamella bertholletiae. Rhizopus oryzae is the single most frequently identified pathogen causing mucormycosis and is responsible for up to 70% of all cases.
The incidence of mucormycosis is unknown and probably underestimated because diagnosis is difficult, and most cases in which a diagnosis is proven histologically or microbiologically are underreported.