key: cord-0866785-a0q0asrd
authors: Drissi, Cyrine
title: Black fungus, the dark side of COVID-19
date: 2021-07-10
journal: J Neuroradiol
DOI: 10.1016/j.neurad.2021.07.003
sha: e852ca782e4605afaaf28cdabb1b24e471298ef2
doc_id: 866785
cord_uid: a0q0asrd

nan

A growing number of case reports and series describe opportunistic fungal infections in COVID-19 patients. Co-morbidities such as diabetes mellitus, coupled with immune dysfunction and use of steroids, are hypothesized as the main causes. Pulmonary invasive aspergillosis is the most common fungal superinfection reported in COVID-19 patients, raising concerns about an additional contributing factor to mortality. 3, 4 More recently, many cases of mucormycosis, often termed "black fungus", have been reported, particularly in Asian countries such as India. An updated and meticulous systematic review of literature assessed data from 30 case reports/series of COVID-19associated mucormycosis reported till 14 May 2021. 5 Cases were mostly from India, USA, and Egypt, respectively representing 73, 10, and 6% of the 99 patients included. The most prevalent comorbidity was diabetes mellitus (85%). The use of glucocorticoids for the management of COVID-19 was observed in 85% of the cases. Rhino-orbital mucormycosis was most common (42%), followed by rhino-orbito-cerebral mucormycosis (24%). Pulmonary mucormycosis was observed in 10 patients (10%). Fungal rhinosinusitis is classified as an invasive or a noninvasive disease depending on histopathological proof of tissue invasion by fungal elements. The invasive type can further be divided into acute, chronic, or chronic granulomatous forms. 6 In this issue of the Journal of Neuroradiology, Ashour MM. et al. report imaging findings of eight patients with confirmed COVID-19 infection that presented with acute invasive fungal rhino-orbital-cerebral sinusitis. 7 All patients were diagnosed with mucormycosis except for one who was proven to have invasive aspergillosis. In most cases, the symptoms occurred at a late stage of the COVID-19 infection. All patients had nasal and paranasal sinus involvement and six of them had orbital infiltration. Intracranial complications of various types were noted on cross-sectional imaging: perineural/meningeal/epidural spread, cavernous sinus involvement, internal carotid thrombosis/vasculitis, cerebral abscesses, and infarctions. All these complications could account for the high long-term morbidity rate of 100% and the mortality rate of 37.5%.

The imaging features described in the Egyptian series were consistent with usual findings of acute invasive fungal rhinosinusitis, with a predominant infiltrative pattern and bone destruction. Typical MR imaging features of acute invasive fungal rhinosinusitis consist in a variable enhancement pattern and a characteristic low signal on T2-weighted images. 8 This can be explained by the fungal elements and the presence of paramagnetic elements such as iron and magnesium as shown in vitro MR evaluation, 9 and/or can be due to the involved mucosa itself in mucormycosis. 10 An early MR imaging finding of nasal mucormycosis is the "black turbinate" sign, featuring a lack of enhancement on postcontrast T1-weighted images, due to devitalization and necrosis of the sinonasal mucosa caused by mycotic vascular invasion. 10 Ashour et al. also review previous case reports and discuss the distinctive imaging features between the acute and chronic forms of invasive fungal sinusitis, based on a series reporting CT and MR findings in eleven patients with chronic invasive or chronic granulomatous invasive fungal sinusitis. 11 Successful management of acute invasive fungal rhino-orbital-cerebral sinusitis requires early diagnosis and prompt initiation of antifungal therapy and surgical intervention.

Over a year into the pandemic, COVID-19 is still a growing challenge for the health care system. Co-infections and superinfections have been identified as one of the predictors of a fatal outcome in COVID-19 patients. Acute invasive fungal rhino-orbital-cerebral sinusitis, most often mucormycosis, is an emerging problem requiring increased vigilance in COVID-19 patients and regular follow-up even after recovery, especially in patients with diabetes mellitus or who had received high doses of glucocorticoids.

Coronavirus Update (Live): 94,993,884 Cases and 2,031,875 Deaths from COVID-19 Virus Pandemic-Worldometer. Available on

Multi-Organ Involvement in COVID-19: Beyond Pulmonary anifestations

Epidemiology of invasive pulmonary aspergillosis among COVID-19 intubated patients: a prospective study

Defining and managing COVID-19-associated pulmonary aspergillosis: the 2020 ECMM/ISHAM consensus criteria for research and clinical guidance

COVID-19-associated mucormycosis: An updated systematic review of literature

Fungal rhinosinusitis: a categorization and definitional schema addressing current controversies

Imaging spectrum of acute invasive fungal rhino-orbital-cerebral sinusitis in COVID-19 patients: A case series and a review of literature

Acute invasive fungal rhinosinusitis: MR imaging features and their impact on prognosis

In vitro evaluation of MR hypointensity in Aspergillus colonies

Black Turbinate" sign: An early MR imaging finding of nasal mucormycosis

Image findings in chronic invasive fungal infection of paranasal sinuses