The nail under fungal siege in patients with type II diabetes mellitus

Global prevalence of onychomycosis in general and special populations: An updated perspective

BACKGROUND

Onychomycosis is a chronic nail disorder commonly seen by healthcare providers; toenail involvement in particular presents a treatment challenge.

OBJECTIVE

To provide an updated estimate on the prevalence of toenail onychomycosis.

METHODS

We conducted a literature search using PubMed, Embase and Web of Science. Studies reporting mycology-confirmed diagnoses were included and stratified into (a) populations-based studies, and studies that included (b) clinically un-suspected and (c) clinically suspected patients.

RESULTS

A total of 108 studies were included. Based on studies that examined clinically un-suspected patients (i.e., with or without clinical features suggestive of onychomycosis), the pooled prevalence rate of toenail onychomycosis caused by dermatophytes was 4% (95% CI: 3-5) among the general population; special populations with a heightened risk include knee osteoarthritis patients (RR: 14.6 [95% CI: 13.0-16.5]), chronic venous disease patients (RR: 5.6 [95% CI: 3.7-8.1]), renal transplant patients (RR: 4.7 [95% CI: 3.3-6.5]), geriatric patients (RR: 4.7 [95% CI: 4.4-4.9]), HIV-positive patients (RR: 3.7 [95% CI: 2.9-4.7]), lupus erythematosus patients (RR: 3.1 [95% CI: 1.2-6.3]), diabetic patients (RR: 2.8 [95% CI: 2.4-3.3]) and hemodialysis patients (RR: 2.8 [95% CI: 1.9-4.0]). The prevalence of onychomycosis in clinically suspected patients was significantly higher likely due to sampling bias. A high degree of variability was found in a limited number of population-based studies indicating that certain pockets of the population may be more predisposed to onychomycosis. The diagnosis of non-dermatophyte mould onychomycosis requires repeat sampling to rule out contaminants or commensal organisms; a significant difference was found between studies that performed single sampling versus repeat sampling. The advent of PCR diagnosis results in improved detection rates for dermatophytes compared to culture.

CONCLUSION

Onychomycosis is an underrecognized healthcare burden. Further population-based studies using standardized PCR methods are warranted.

Clinico-Mycological Study of Onychomycosis in Indian Diabetic Patients

Background

Onychomycosis (OM) is the most common nail disorder accounting for 40-50% of all onychopathies. Onychomycosis is caused by dermatophytes in majority, mostly Trichophyton (T.) rubrum followed by T. mentragrophytes var. interdigitale. However, there is a variation in the etiological profile with the subset of population, time, and geographical location. In immunocompromised hosts, non-dermatophytic molds (NDMs) and yeasts like Candida albicans and Candida parapsilosis are the main causative agents. Diabetes mellitus (DM) is a well-established risk factor for OM.

Aim and Objectives

This study was conducted to determine the clinical and mycological characteristics of OM in diabetic patients and to evaluate the clinico-etiological correlation, if any.

Materials and Methods

Three hundred consecutive diabetic patients were screened, of whom 102 (34%) patients were diagnosed with OM based on clinical, mycological, dermoscopic, and histological criteria.

Results

Distal lateral subungual onychomycosis was the most common clinical variant seen in 80 (78.43%) patients. Fungal culture was positive in 57 (55.88%) of which NDMs constituted approximately half (47.61%) of the isolates, followed by Candida species (30.15%) and dermatophytes (22.22%). The clinico-mycological correlation was performed to look for the association of various fungi with the clinical type of OM. Distal lateral subungual onychomycosis was majorly caused by NDMs (51.02%), followed by Candida species (28.57%), and dermatophytes (20.40%).

Conclusion

Non-dermatophytic molds are increasingly incriminated as the causative organisms for OM in DM and must be considered as potential pathogens in the present scenario, thus necessitating the change in the treatment options accordingly.

In search of dermatophytes - frequency and etiology of fungal infections in patients with and without diabetes mellitus

INTRODUCTION

Onychomycosis is a frequent nail disorder, accounting for up to 50% of all nail problems. Treatment of onychomycosis is expensive and requires a long time of antifungal medications. Consequently, a proper and faster diagnosis is necessary. Especially for those patients with diabetes mellitus, where onychomycosis is among the most significant predictors of foot ulcer and possible severe complications.

Onychomycosis in Patients with Diabetes Mellitus in Africa: A Global Scoping Review, 2000-2021

Onychomycosis is commonly studied in Africa but not in patients with diabetics despite having a significant number of her population living with diabetes mellitus (DM). Our review highlights a total of 15 studies with only two from Africa over the past two decades; 8 (53.3%) from Asia, 4 (26.7%) from Europe, 2 (13.3%) from Africa and 1 (6.7%) from North America. A total number of 4321 participants were involved with onychomycosis prevalence of 35.3% (1527/4321). Seven studies documented preponderance of onychomycosis in males, one showed preponderance in females, one showed no statistically significant difference in gender, while correlation with gender was unclear in the remainder. The risk factors identified were duration of diabetes, increasing age, occupation (agriculture), subclinical atherosclerosis, metabolic syndrome, obesity, triglyceride levels, and glycosylated haemoglobin. Three case control studies showed a statistically significant correlation between onychomycosis and individuals with DM. Diagnosis was mainly by microscopy and culture with Trichophyton (T) rubrum as the predominant isolate. Fungal nail infections are grossly underdiagnosed and/or underreported in Africa and hence the need for improved awareness and diagnosis especially in patients with DM. Although focused on Africa, this study also revealed paucity of data on onychomycosis in diabetic patients living in the Americas despite evidence from the literature showing a significant number of individuals from that region are living with diabetes. The need to evaluate this at-risk population for onychomycosis cannot be over emphasized.

Candida sp. Infections in Patients with Diabetes Mellitus

Candidiasis has increased substantially worldwide over recent decades and is a significant cause of morbidity and mortality, especially among critically ill patients. Diabetes mellitus (DM) is a metabolic disorder that predisposes individuals to fungal infections, including those related to Candida sp., due to a immunosuppressive effect on the patient. This review aims to discuss the latest studies regarding the occurrence of candidiasis on DM patients and the pathophysiology and etiology associated with these co-morbidities. A comprehensive review of the literature was undertaken. PubMed, Scopus, Elsevier’s ScienceDirect, and Springer’s SpringerLink databases were searched using well-defined search terms. Predefined inclusion and exclusion criteria were applied to classify relevant manuscripts. Results of the review show that DM patients have an increased susceptibility to Candida sp. infections which aggravates in the cases of uncontrolled hyperglycemia. The conclusion is that, for these patients, the hospitalization periods have increased and are commonly associated with the prolonged use of indwelling medical devices, which also increase the costs associated with disease management.

Prevalence and Epidemiology of Onychomycosis

The prevalence of onychomycosis has been estimated at approximately 6.48% (95% confidence interval 6.09–6.88%) within the Canadian population. Dermatophytes are the most commonly cultured organisms, appearing in approximately 75 to 91% of nails with fungal involvement, with Trichophyton rubrum and Tricophyton mentagrophytes most commonly isolated. However, Candida spp and nondermatophyte molds are also sometimes cultured. The most common presentation is distal and lateral subungual onychomycosis (DLSO), which can involve 75% of patients with pedal onychomycosis. The distribution of DLSO, superficial white onychomycosis, and proximal subungual onychomycosis (PSO) has been reported to be 360:59:1 in patients with mycologic confirmation of onychomycosis; however, some reported that the incidence of PSO is slightly higher in immunocompromised individuals. Age, gender, family history, and the presence of tinea pedis are all elements associated with a nail fungal infection. In addition, many conditions, including diabetes mellitus, immune disorders, and vascular disease, have been associated with the presence of onychomycosis. When choosing the best treatment regimen for individuals with onychomycosis, it is very important to consider all of the factors involved, including the infecting species, the presentation of the disease, the level of disease progression, and its predisposing factors.

In vitro antifungal activity of ME1111, a new topical agent for onychomycosis, against clinical isolates of dermatophytes

The treatment of onychomycosis has improved considerably over the past several decades following the introduction of the oral antifungals terbinafine and itraconazole. However, these oral agents suffer from certain disadvantages, including drug interactions and potential liver toxicity. Thus, there is a need for new topical agents that are effective against onychomycosis. ME1111 is a novel selective inhibitor of succinate dehydrogenase (complex II) of dermatophyte species, whose small molecular weight enhances its ability to penetrate the nail plate. In this study, we determined the antifungal activity of ME1111 against dermatophyte strains, most of which are known to cause nail infections, as measured by the MIC (n = 400) and the minimum fungicidal concentration (MFC) (n = 300). Additionally, we examined the potential for resistance development in dermatophytes (n = 4) following repeated exposure to ME1111. Our data show that the MIC90 of ME1111 against dermatophyte strains was 0.25 μg/ml, which was equivalent to that of the comparators amorolfine and ciclopirox (0.25 and 0.5 μg/ml, respectively). ME1111 was fungicidal at clinically achievable concentrations against dermatophytes, and its MFC90s against Trichophyton rubrum and Trichophyton mentagrophytes were 8 μg/ml, comparable to those of ciclopirox. Furthermore, ME1111, as well as ciclopirox, did not induce resistance in 4 dermatophytes tested. Our studies show that ME1111 possesses potent antifungal activity and suggest that it has low potential for the development of resistance in dermatophytes.

Proportion of lower limb fungal foot infections in patients with type 2 diabetes at a tertiary care hospital in Sri Lanka

BACKGROUND

Superficial fungal foot infection (SFFI) in diabetic patients increases the risk of developing diabetic foot syndrome. Sixteen percent of urban population is suffering from diabetes in Sri Lanka. As the diabetes patients are more prone to get fungal foot infections, early intervention is advisable owing to the progressive nature of the infection. There is no data on the prevalence of SFFIs in diabetic patients in Sri Lanka.

OBJECTIVE

To determine the etiological agents causing SFFI in patients with type 2 diabetes.

MATERIALS AND METHODS

Three hundred eighty five diabetic patients were included. Nail clippings and swabs were collected from the infected sites using the standard protocol. Laboratory identification was done and pathogens were identified to the species level by morpho physiological methods.

RESULTS

Clinically 295 patients showed SFFI, of which 255 (86%) were mycologically confirmed for infection. Out of 236 direct microscopy (KOH) positives, 227 (96%) were culture positive. Two hundred and fifty one patients (98%) with SFFI had diabetes for more than 10 years. Of the patients with SFFIs 92% had >100 mg/dl FBS and 81% had >140 mg/dl PPBS levels and 80% had both elevated FBS and PPBS. Non-dermatophyte fungal species were the commonest pathogens followed by yeast and dermatophytes.

CONCLUSION

Aspergillus niger was the commonest pathogen followed by Candida albicans. SFFIs were seen significantly with the increasing age, gender, duration of diabetes and with less controlled glycaemic level.

The skin landscape in diabetes mellitus. Focus on dermocosmetic management

Background

Some relationships are established between diabetes mellitus (DM) and a series of cutaneous disorders. Specific dermatoses are markers for undiagnosed DM. Other disorders represent supervening complications in an already treated DM patient.

Objective

To review the information about dermocosmetic care products and their appropriate use in the management and prevention of dermatoses related to DM.

Method

The peer-reviewed literature and empiric findings are covered. Owing to the limited clinical evidence available for the use of dermocosmetics, a review of the routine practices and common therapies in DM-related dermatoses was conducted.

Results

Some DM-related dermatoses (acanthosis nigricans, pigmented purpuric dermatosis) are markers of macrovascular complications. The same disorders and some others (xerosis, Dupuytren’s disease) have been found to be more frequently associated with microangiopathy. Other skin diseases (alopecia areata, vitiligo) were found to be markers of autoimmunity, particularly in type 1 DM. Unsurprisingly, using dermocosmetics and appropriate skin care has shown objective improvements of some DM-related dermatoses, such effects improve the quality of life. The most common skin manifestations of DM fall along continuum between “dry skin,” xerosis, and acquired ichthyosis, occurring predominately on the shins and feet. Dermocosmetic products improve the feeling of well-being for DM patients.

Comparison of diagnostic methods in the evaluation of onychomycosis

Onychomycosis is a common nail problem, accounting for up to half of all nail diseases. Several nail disorders may mimic the onychomycosis clinically. Therefore, a sensitive, quick, and inexpensive test is essential for screening nail specimens for the administration of the proper drug. The aim of this study was to compare 4 different diagnostic methods in the evaluation of onychomycosis and to determine their sensitivity, specificity, positive predictive value, and negative predictive value. In a cross-sectional study, nail specimens were collected from 101 patients suspected to have onychomycosis during a 14-month period. The nail specimens were examined using potassium hydroxide (KOH) 20 %, KOH-treated nail clipping stained with periodic acid-Schiff (KONCPA), and calcofluor white (CFW) stain, and grew a fungal culture. The culture was chosen as the gold standard for statistical analysis using the McNemar and chi-square tests. Out of 101 patients, 100 (99 %) patients had at least 1 of the 4 diagnostic methods positive for the presence of organisms. The positive rates for the fungal culture, KOH preparation, CFW, and KONCPA were 74.2, 85.1, 91.09, and 99.01 %, respectively. The sensitivity and negative predictive value of KONCPA was 100 %. KONCPA was the most sensitive among the tests and was also superior to other methods in its negative predictive value. KONCPA was easy to perform, rapid, and gave significantly higher rates of detection of onychomycosis compared to the standard methods of KOH preparation and fungal culture. Therefore, KONCPA should be the single method of choice for the evaluation of onychomycosis.

Dermatomycosis in lower limbs of diabetic patients followed by podiatry consultation

BACKGROUND

Diabetic patients are particularly susceptible to fungal infections due to modifications that occur in their immunological system. These modifications compromise natural defences, such as skin and nails, especially from lower limbs.

AIMS

Assessing the presence of dermatomycosis in lower limbs of Portuguese diabetic patients followed on Podiatry consultation. Determination of possible predisposing factors and the most frequent fungal species associated with the cases are included in the study.

METHODS

A six-month prospective study was carried out in 163 diabetic patients with signs and symptoms of dermatomycosis followed by Podiatry at the Portuguese Diabetes Association in Lisbon. Samples from the skin and/or nails of the lower limbs were collected and demographic and clinical data of those patients were recorded.

RESULTS

Trichophyton rubrum was the most frequently isolated dermatophyte (12.1%), followed by Trichophyton mentagrophytes (7.7%) and Trichophyton tonsurans (4.4%). Our study showed positive associations between type 2 diabetes and the presence of dermatomycosis in the studied population (p=0.013); this association was also shown between the occurrence of dermatomycosis and the localization of the body lesion (p=0.000). No other predisposing factor tested was positively associated with infection (p>0.05).

CONCLUSIONS

Data on superficial fungal infections in diabetic patients are scarce in Portugal. This study provides information on the characterization of dermatomycosis in lower limbs of diabetic patients.

Efficacy, safety and tolerability of topical terbinafine nail solution in patients with mild-to-moderate toenail onychomycosis: results from three randomized studies using double-blind vehicle-controlled and open-label active-controlled designs

BACKGROUND

Terbinafine nail solution (TNS) was developed for the treatment of onychomycosis.

OBJECTIVE

To assess the efficacy of TNS vs. vehicle and amorolfine 5% nail lacquer.

METHODS

Subjects with mild-to-moderate toe onychomycosis (25% to ≤75% nail-involvement, matrix uninvolved) were randomized to receive either TNS or vehicle in two double-blind studies, and to TNS or amorolfine in an active-controlled, open-label study. Primary endpoint was complete cure (no residual clinical involvement and negative mycology) at week 52. Secondary endpoints were mycological cure (negative mycology defined as negative KOH microscopy and negative culture) and clinical effectiveness (≤10% residual-involvement and negative mycology) at week 52.

RESULTS

Complete cure was not different between TNS vs. vehicle and amorolfine. Mycological cure was higher with TNS vs. vehicle, as was clinical effectiveness with TNS vs. vehicle, and TNS and amorolfine were not different for secondary efficacy endpoints. Patients achieving mycological cure had a better clinical outcome, and efficacy was improved in subjects with milder disease. Post hoc analysis suggests that nail thickness is an important prognostic factor. Moreover, mycological cure may require 6 months of treatment regimen while complete cure and clinical effectiveness may be achievable only after 10 months. A simulation study suggests that longer treatment duration would have resulted in higher complete cure with TNS vs. vehicle. Study treatments were well-tolerated.

CONCLUSION

Primary efficacy objectives were not met in the studies reported herein. Possible reasons for failure to achieve significant outcomes include insufficient length of treatment; stringency of primary endpoint and severity of nail involvement of study population.

Toenail onychomycosis in diabetic patients: issues and management

Diabetes mellitus may be associated with serious sequelae, such as renal disease, retinopathy, and diabetic foot. A recent large prospective study has shown that onychomycosis is among the most significant predictors of foot ulcer. As the severity of onychomycosis may be associated with the length of time the individual has had the infection, early intervention is advisable owing to the progressive nature of the fungal infection. If left untreated, toenails can become thick, causing pressure and irritation, and thus act as a trigger for more severe complications. In the treatment of onychomycosis, compliance and drug interactions are important considerations, as diabetic patients frequently take concomitant medications. Terbinafine and itraconazole have been investigated for the treatment of onychomycosis in diabetic patients and have been shown to have efficacy and safety profiles comparable to those in the nondiabetic population. Data from clinical trials and postmarketing surveillance suggest that drug interactions resulting in hypoglycemia may not be an important issue when itraconazole and terbinafine are used to treat diabetic patients receiving concomitant hypoglycemic medications. Patient advice and education in improved foot care are an integral part of onychomycosis management, and help achieve long-term cure and reduce the complications of diabetic foot.

Metabolic syndrome associated with toenail onychomycosis in Taiwanese with diabetes mellitus

BACKGROUND

Onychomycosis is a complication of diabetes mellitus (DM), which has a deleterious impact on the quality of life. Aim To explore the prevalence of onychomycosis amongst Taiwanese diabetics, and to analyze the factors associated with onychomycosis after adjusting for age and sex.

METHODS

A total of 1245 Taiwanese diabetics were enrolled, and a nested case-control study was performed by onychomycosis outcome and the exposures were compared.

RESULTS

The overall prevalence of onychomycosis among DM patients was 30.76% (383/1245), with a significantly higher prevalence in men than in women (P = 0.024). The factors associated with onychomycosis in matched pairs by gender and age were analyzed in 375 pairs. It was found that metabolic syndrome, obesity, triglyceride (TG) levels, and glycosylated hemoglobin (HbA1c) were associated with onychomycosis (P < 0.05).

CONCLUSION

Higher prevalence rates of onychomycosis were found in men and older DM patients. Metabolic syndrome, obesity, high TG levels, and poor glycemic control were associated with onychomycosis.

Clinicopathologic presentations of dermatomycoses in cancer patients

Many of the skin fungal infections in cancer patients may look similar to those infections in non-cancer patients. However, in some cases, they become more extensive and even life threatening. Prolonged and severe neutropenia is the main risk factor for the dramatic issue of fungal infections. The dermatomycoses in cancer patients can be classified in four broad groups: primary superficial dermatophytoses, primary superficial yeast infections, opportunistic mold infections with distinct potential for dissemination and secondary cutaneous manifestations of fungaemia. Occasionally, more than one fungus are found inside a given skin lesion. A special condition is represented by the mycotic colonization of mucosal squamous cell carcinomas. Angio-invasion by fungi accounts for the frequency of disseminated infections prevailing in immunocompromised cancer patients. In case of skin involvement, the dermatologist may assist by recognizing subtle semiological signs and performing biopsies for swift histological examination, molecular biology and/or culture.

Characteristics of superficial fungal infections in the Riyadh region of Saudi Arabia

BACKGROUND

The prevalence and characteristics of superficial fungal infections (SFIs) vary with climatic conditions, lifestyle, and population migration patterns. This study was undertaken to determine the characteristics of SFIs amongst patients visiting the dermatology clinic of Riyadh Military Hospital, Riyadh, Saudi Arabia, during the period 2003-2005.

METHODS

One hundred and nineteen patients with confirmed SFI (37 males and 82 females), aged between 5 months and 67 years, were included in this study. The diagnosis of SFI was based on clinical presentation confirmed by laboratory analysis. The type of mycotic pathogen and the site of infection were recorded as a function of age and sex.

RESULTS

Onychomycosis (40.3%) was the most frequent infection, followed by tinea capitis (21.9%), tinea pedis (16%), tinea cruris (15.1%), and tinea corporis (6.7%). Tinea capitis was most prevalent (15.1%) in children (male to female ratio, 1 : 1.57), whereas tinea pedis was most common (11.8%) in adults (male to female ratio, 1 : 2.5). Trichophyton mentagrophytes and Microsporum canis were the most common dermatophytes responsible for tinea infections, and T. mentagrophytes, Candida spp., and Aspergillus spp. were mainly responsible for onychomycosis.

CONCLUSION

The prevalence of SFI was twofold greater in females than males. Children were most commonly affected by tinea capitis, whereas adults generally suffered from tinea pedis. The frequency of onychomycosis was nearly three times higher in adults. This study clearly shows that SFIs are of concern in both genders and in all age groups.

Emerging therapeutic agents for onychomycosis

Onychomycosis is a frequent disorder that represents the most prevalent fungal infection, particularly among older individuals. Diverse fungi of the dermatophyte, non-dermatophyte mold and yeast families have been reported to be responsible for onychomycosis. The output from the pharmaceutical industry of new antifungals to treat onychomycosis has been limited over the last decade. Present treatment options include both oral and topical drugs, with oral therapies giving better outcomes. However, neither of these treatment options provides high cure rates that are durable. At present, azoles and allylamines are keeping the pivotal roles. New derivatives with a favorable risk-benefit ratio and new formulations of older azoles seem to be promising. Thus, ongoing drug development activities have focused on novel delivery technologies to facilitate incorporation of existing antifungal drugs inside the nail plate and the discovery of new active antifungals.

Effects of foot care intervention including nail drilling combined with topical antifungal application in diabetic patients with onychomycosis

We performed periodical foot care intervention including nail drilling combined with topical antifungal application for 6 months or more in 24 diabetic patients with onychomycosis who were not receiving oral antifungals, and evaluated its effects. The type of onychomycosis was superficial white onychomycosis (SWO) in eight patients, and distal-lateral subungual onychomycosis (DLSO) in 16. The state of onychomycosis was evaluated according to the Scoring Clinical Index for Onychomycosis (SCIO). Of the eight patients with SWO, none showed aggravation of the onychomycosis state, and two were cured 6 months after the initiation of intervention and two after 1 year (total of four patients, 50%). In the patients with DLSO, the SCIO score was 18.1 +/- 6.5 before intervention but significantly decreased to 14.6 +/- 6.6 6 months after intervention. In 12 patients who we were able to consecutively follow up for 1 year, the SCIO score also significantly decreased compared with the score before intervention. Thus, foot care intervention including nail drilling combined with topical antifungal application had effects on onychomycosis and achieved cure in some patients with SWO. In addition, intervention increased patients' awareness of foot care, showing educational effects. Therefore, foot care intervention including nail drilling may be useful.

Toenail onychomycosis: current and future treatment options

Onychomycosis is a common disease affecting as much as 8% of the general population. Treatment of onychomycosis is challenging, complicated by low cure rates and relatively high relapse rates. This paper reviews the efficacy of current oral, topical, and surgical treatment options. Currently, the treatment of choice for toenail onychomycosis is oral terbinafine because of its high efficacy, low relapse rates, and cost-effectiveness. Oral itraconazole or fluconazole could be considered for infections caused by Candida. Topical therapies may be a useful adjunct to these systemic therapies, but are less effective when used alone. More research is needed to determine the best measures for preventing reinfection.

Onychomycosis in older patients

Onychomycosis represents the most frequent nail disorder. Its prevalence is influenced by gender, age and several comorbid diseases. Accurate diagnosis relies on laboratory examination, particularly nail histomycology. This method refers to the microscopic examination of histological sections prepared from nail clippings for the purpose of detecting the presence of invading fungi. The pathogens may belong to one or a combination of the groups of dermatophytes, yeasts or nondermatophyte molds. The choice of the diagnostic laboratory method influences the accuracy of the information. Histomycology is recognized to be the most sensitive and specific method. The prevalence of onychomycosis in the elderly population varies according to gender and the nature of the fungal pathogen. Epidemiological figures differ according to the nature of the reference population. In particular, it is of the utmost importance to establish the ratio between the raw numbers of onychomycoses and the total number of individuals in the same age group living in the same geographical area.