Invasive rhinocerebral mucormycosis: Imaging the temporal evolution of disease in post COVID-19 case with diabetes: A case report.

Background: Rhinocerebral mucormycosis (RCM) is a rare, fatal, invasive fungal infection infecting mainly patients with immunocompromised conditions, such as diabetes mellitus, hematologic malignancies, and organ transplantations. Coronavirus disease 2019 (COVID-19) disease in these patients further weakens the immune system due to several factors, including hypoxia, corticosteroid usage (further increasing hyperglycemic status), mechanical ventilation, increased serum ferritin levels, endothelitis due to free radicals, and glucose receptor protein upregulation. Timely diagnosis, judicious treatment decisions, and diabetes control with proper treatment guidelines in patients with coexisting COVID-19 disease can reduce complication rates and improve survival.

Case summary: A 75-year-old male patient with diabetes and hypertension diagnosed with COVID-19 presented to the emergency department. Laboratory examinations revealed elevated blood glucose levels, as well as ketone bodies in the urine. He was treated with oxygen and steroids, as well as insulin to correct blood glucose levels. He complained of a headache 10 d later, and imaging demonstrated mucosal thickening in bilateral sphenoidal, ethmoidal, and maxillary sinuses with hyperdense foci in the right maxillary sinus but without central nervous system involvement. Surgical debridement was performed, and a histopathological study revealed fungi hyphae. Systemic antifungals (amphotericin b and posaconazole) were administered. Subsequently, on 15^th day he developed right lower limb weakness and left lateral rectus palsy. There was slow but steady progress, and he was discharged. However, he presented to emergency department 1mo later with altered sensorium and poor control of diabetes resulted in an intracranial spread of mucormycosis, which ultimately led to the patient's poor prognosis and slow recovery.

Conclusion: Prompt early diagnosis, judicious treatment decisions, and diabetes control with proper treatment guidelines are necessary in patients with COVID-19 associated invasive RCM to reduce complication rates and improve patient survival.