First Case of Rhinocerebral Mucormycosis Caused by Lichtheimia ornata, with a Review of Lichtheimia Infections.

BACKGROUND

Lichtheimia species are emerging opportunistic fungal pathogens in the Mucorales, causing serious skin and respiratory infections in immunocompromised patients. Established agents are Lichtheimia corymbifera and L. ramosa, while L. ornata is a novel agent. Available data on a species-specific analysis of Lichtheimia infections are limited.

METHODS

The first case of a fatal rhino-orbital-cerebral infection in a hematopoietic stem cell transplantation recipient caused by L. ornata is reported; the agent was identified by sequencing the ITS ribosomal region. We reviewed the literature on mucormycosis due to Lichtheimia species between 2009 and 2018, with an analysis of risk factors and epidemiological and clinical data.

RESULTS

In addition to our Lichtheimia ornata case, 44 cases of human Lichtheimia were analyzed. Lichtheimia predominated in Europe (68.2%), followed by Asia (16%), and Africa (9%). The most common underlying condition was hematological malignancy (36.3%), followed by trauma/major surgery (27.3%), while diabetes mellitus was rare (11.4%). Site of infection was mostly skin and soft tissues (45.5%) and lung (25%), while relatively few cases were disseminated (13.6%) or rhinocerebral (11.4%). Mortality (36.4%) was mainly due to disseminated and rhinocerebral infections.

CONCLUSION

In contrast to Rhizopus, the most common agent of mucormycosis recorded in patients with diabetes mellitus, Lichtheimia infections were primarily associated with hematological malignancies and major skin barrier damage. Given the fact that classical rhinocerebral mucormycosis remains difficult to treat, independent of causative species, timely application of amphotericin B accessory to debridement may be required for patient survival.