Onychomycosis associated with diabetic foot syndrome: A systematic review

Abstract

Background: A systematic review was conducted to investigate the prevalence of onychomycosis in patients with diabetes. The association of onychomycosis with risk factors in patients with diabetic foot syndrome was also examined.

Methods: The recommendations in the preferred reporting items for systematic reviews and meta-analysis (PRISMA) checklist were applied, and the included studies were assessed using the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) method. Searches were conducted in October 2022 using PubMed (Medline) and Scopus for clinical studies, clinical trials, comparative studies, observational studies, and randomised clinical trials or controlled clinical trials addressing the prevalence and consequences of onychomycosis in patients with diabetes, diagnoses or treatments. Two authors performed the study selection and data extraction, and any discrepancies between the two reviewers were resolved through discussion with a third reviewer.

Results: The systematic review included ten studies that met the inclusion criteria, and these studies enrolled 5664 patients with diabetes. Among these patients, 29.18% had onychomycosis that was mainly caused by Trichophyton rubrum. A significant association was found between the occurrence of onychomycosis and the presence of diabetic neuropathy (p = .012) and elevated glycosylated haemoglobin values (p = .039). There was no significant association between onychomycosis and ulceration (p = .185). Eight studies had a grade 4 level of evidence and a grade C recommendation, and one study had a grade 1b level of evidence and a grade A recommendation.

Conclusion: The information described in the literature is insufficient and heterogeneous regarding the association of risk factors and ulceration in patients with diabetic foot compared with developing onychomycosis. There is also a need to implement onychomycosis diagnostic testing instead of relying only on a clinical diagnosis. Additional prospective, randomised, comparative studies are needed to increase the quality of studies in the literature.

Keywords: diabetes mellitus; diabetic foot; diabetic neuropathy; diagnosis; onychomycosis; ulcer.