Understanding the Interplay: A Descriptive Synthesis of COVID-19-Associated Mucormycosis in Diabetic Patients

During the COVID-19 pandemic, COVID-19-associated mucormycosis (CAM) emerged as a severe and often fatal complication, particularly among patients with diabetes mellitus. The increase in invasive fungal infections has been strongly linked to diabetes, COVID-19-related immune dysregulation, hyperglycaemia, and widespread corticosteroid use. This systematic review provides a descriptive synthesis of the relationship between COVID-19, mucormycosis, and diabetes, focusing on epidemiology, clinical features, management, and outcomes.

A systematic search of PubMed/MEDLINE, Scopus, Web of Science, and the Cochrane Library was conducted for studies published between 1 April 2020 and 30 November 2025. Studies reporting CAM in diabetic patients were included. Eligible designs comprised case reports, case series, and observational studies. Study selection followed PRISMA 2020 guidelines, and findings were synthesized qualitatively, with stratification by evidence level (case reports/series vs. cohort and cross-sectional studies).

Thirty-six studies met the inclusion criteria. Diabetes was present in most CAM cases, with poor glycaemic control and diabetic ketoacidosis frequently reported. Corticosteroid therapy was identified as a major contributing factor. Rhino-orbital-cerebral mucormycosis was the most common presentation. Early antifungal treatment, surgical debridement, and strict glycaemic control were associated with improved outcomes, whereas delayed diagnosis and cerebral involvement were linked to increased mortality. Approximately 40% of the included studies were case reports or case series (Level 4 evidence), necessitating cautious interpretation of findings.

Diabetes significantly influences the development and outcomes of CAM. Judicious corticosteroid use, optimal glycaemic control, early diagnosis, and multidisciplinary management are essential to reduce morbidity and mortality. Although conclusions are limited by the predominance of lower-level evidence, consistent patterns highlight diabetes and corticosteroid exposure as major risk factors.