Onychomycosis and Tinea Pedis in the Feet of Patients With Diabetes

Abstract

This study aimed to determine the prevalence of onychomycosis and interdigital tinea pedis in a cohort of Spanish patients with diabetes in whom onychomycosis was clinically suspected (n = 101). Samples from a first toenail scraping and the fourth toe clefts were subjected to potassium hydroxide direct vision and incubated in Sabouraud and dermatophyte test medium. Fifty-eight samples were also analyzed by a pathologist using periodic acid-Schiff staining and Calcofluor white direct fluorescence microscopy. Onychomycosis was only confirmed in 41 patients (40.6%). The most frequent aetiological agent was Trichophyton rubrum, isolated in 10 patients (36%), followed by Candida parapsilosis in 7 patients (25%). Tests on the fourth toe cleft samples were only positive in 11 patients (10.9%), and in all cases, onychomycosis was also diagnosed. Neuroischemic foot was the only significant variable associated with onychomycosis in the univariate analysis ( P < .01). A positive result for mycosis in the fourth toe cleft was found in 11 cases (10.9%) and was associated with a history of myocardial infarction ( P< .01; odds ratio [OR]: 84.2, confidence interval [CI]: 6.8-1036.4) and neuroischemic foot ( P< .01; OR: 13.7, CI: 12.6-71.6) in the multivariate model. In conclusion, the prevalence of onychomycosis and tinea pedis in patients with diabetes in whom onychomycosis was clinically suspected was 40.6% and 10.9%, respectively. In addition, onychomycosis was not always associated with tinea pedis. These results show that clinical diagnosis has low accuracy in people with diabetes mellitus, and that diagnosis should not be based on clinical toenail characteristics alone.

Identification of Fungi Involved in Onychomycosis in Patients of a Spanish Rural Area

“…T. interdigitale was more common than T. rubrum in dermatophytic onychomycosis. Previous studies carried out in urban areas of Spain revealed that dermatophytes and T. rubrum were the most common etiological agents of onychomycosis [16,20,21]. We believe that the discrepancies between our findings and those others are due to different lifestyles, rural vs. urban.…”

Onychomycosis in Two Populations with Different Socioeconomic Resources in an Urban Nucleus: A Cross-Sectional Study

“…With regard to clinical presentation, TDO and MO are the most common among the housed population and among the homeless population DSO and MO. Notwithstanding that fact, we have not found any recent studies that match the clinical presentations of our research since most studies describe that the most frequent clinical presentation is DLSO [ 6 , 21 , 22 ]. This could be explained by our sample size.…”

“…Regarding the housed group, this prevalence is 62.5%, which enhances the results obtained by Babayani, M. et al, in their study published in 2018 which found prevalence was 65.5% ( n = 118) [ 20 ]. Aragón-Sánchez, J. et al, in their study published in 2021 using similar techniques as those used in this study, obtained diagnoses confirmation in 40.5% of the cases with clinical suspicion ( n = 101) [ 21 ]. However, this comparison should be taken cautiously since their target population was only diabetic.…”

Onychomycosis associated with diabetic foot syndrome: A systematic review

“…Chronic hyperglycaemia, neuropathy and peripheral arterial disease damage the immune system by affecting polymorphonuclear leukocytes and phagocytic functions. These conditions are present in diabetic foot patients and contribute to the development of fungal and bacterial skin infections as well as fungal nail infections 7,8 …”