Factors associated with presence and severity of toenail onychomycosis in patients with diabetes: A cross-sectional study

Objective: To identify the factors associated with toenail onychomycosis in patients with diabetes. Methods: In this cross-sectional, observational study, the presence and severity (area of nail involvement and nail thickness) of toenail onychomycosis and related factors were examined. One hundred and thirteen patients with diabetes were surveyed at the Diabetic Foot Outpatient Clinic at the University hospital. Toenails of all patients enrolled in the survey were examined whether onychomycosis was present or absent by mycological examination. The severity of onychomycosis was assessed by clinical evaluation, using the area of nail involvement and the nail thickness. Results: Fifty eight (51.3%) patients had toenail onychomycosis. The presence of onychomycosis was significantly associated with not washing of feet every day (the unadjusted model, OR: 3.45, 95% CI: 1.24-9.65, P=0.018). The median area of nail involvement was 50.0% (range 5.0-100.0%). A larger area of involvement was significantly related to a lower toe brachial index (β=-67.46, P=0.040). The median nail thickness with onychomycosis was 1.14mm (range 0.68-9.86mm). Increasing thickness was significantly correlated with higher hemoglobin A ₁c levels (β=0.98, P=0.003). Conclusions: This study suggested that daily washing of feet may reduce the risk of onychomycosis in patients with diabetes. This suggested that education regarding the importance of the washing of feet every day and support for continuous self-care might be effective in the prevention of onychomycosis in patients with diabetes. Furthermore, good control of blood glucose might prevent increasing nail thickness. This study may highlight importance of early nursing educational intervention to improve patients' daily life style for prevention of onychomycosis induced diabetic foot ulcers.