Background: The number of individuals diagnosed with diabetes mellitus is increasing worldwide. Although onychomycosis is often observed in diabetics, there have been no large studies of its epidemiology in this patient group in India.
Methods: We studied the prevalence of onychomycosis in diabetics attending the Diabetes Clinic at the Postgraduate Institute of Medical Education and Research, Chandigarh, India, and compared it with that in a nondiabetic control group. A total of 400 diabetic subjects (237 males, 163 females), aged 48.8 +/- 0.5 years (mean +/- SD), were evaluated.
Results: The prevalence of onychomycosis in the diabetic and control groups was 17% and 6.8%, respectively, the difference being statistically significant (P < 0.001). The presence of onychomycosis was found to correlate significantly with increasing age (P < 0.01) and male gender (P < 0.05) in both diabetic and control groups. From diabetics, yeasts were the most common isolate (48.1%), followed by dermatophytes and nondermatophyte molds in 37% and 14.8%, respectively. In the control group, the distribution of yeasts, dermatophytes, and nondermatophyte molds was 25%, 62.5%, and 12.5%, respectively. After controlling for age and sex, a stepwise logistic regression demonstrated that significant predictors for onychomycosis included the duration of diabetes (P < 0.01), absent or feeble peripheral pulses (P < 0.15), peripheral neuropathy (P < 0.05), and retinopathy (P < 0.001).
Conclusions: Diabetics were found to be 2.5 times more likely to have onychomycosis than the controls. Predisposing factors included increasing age, male gender, duration of diabetes, impaired peripheral circulation, peripheral neuropathy and retinopathy.