Safety of current therapies for onychomycosis

Nails in older adults

As the world's population of adults greater than 60 years old continues to increase, it is important to manage nail disorders that may impact their daily lives. Nail disorders may have significant impact on quality of life due to decreased functionality, extreme pain, or social embarrassment. In this review, we discuss nail disorders affecting older patients, including physiologic, traumatic, drug-induced, infectious, environmental, inflammatory, and neoplastic conditions. Diagnosis of these conditions involves a detailed history, physical examination of all 20 nails, and depending on the condition, a nail clipping or biopsy and/or diagnostic imaging. Nails grow even more slowly in older adults compared to younger individuals, and therefore it is important for accurate diagnosis, and avoidance of inappropriate management and delay of treatment. Increased awareness of nail pathologies may help recognition and management of nail conditions in older adults.

The Preparation and Evaluation of a Hydrochloride Hydrogel Patch with an Iontophoresis-Assisted Release of Terbinafine for Transdermal Delivery

Background: Terbinafine hydrochloride (TEB) is a broad-spectrum antifungal medication commonly used to treat fungal infections of the skin. This study designed a hydrogel patch assisted by an iontophoresis system to enhance the transdermal permeability of TEB, enabling deeper penetration into the skin layers. Methods: The influences of current intensity, pH levels, and drug concentration on the TEB hydrogel patch's permeability were explored using an adaptive ion electroosmosis system. The pharmacokinetic profile, facilitated by iontophoresis for transdermal permeation, was analyzed through the application of microdialysis technology. Scanning electron microscopy and transmission electron microscopy were employed to assess the impact of ion electroosmotic systems on skin integrity. Results: The cumulative drug accumulation within 8 h of the TEB hydrogel patches, assisted by iontophoresis, was 2.9 and 7.9 times higher than without iontophoresis assistance and TEB cream in the control group, respectively. TEB hydrogel patches assisted by iontophoresis can significantly increase the permeability of TEB, and the AUC(0-8 h) was 3.4 and 5.4 times higher, while the Cmax was 4.2 and 7.3 times higher than the TEB hydrogel patches without iontophoresis, respectively. This system has no significant impact on deep-layer cells. Conclusions: This system may offer a safe and effective clinical strategy for the local treatment of deep antifungal infections.

Antifungal Selection for the Treatment of Onychomycosis: Patient Considerations and Outcomes

Onychomycosis, a common fungal nail infection, affects >20% of adults over age 60 and >50% of people over age 70. Onychomycosis may cause pain, psychosocial problems, and secondary infections, therefore meriting treatment. This review describes the range of treatment modalities, including FDA-approved systemic drugs and topical therapies. Additionally, new and emerging oral and topical therapies are discussed. We emphasize the importance of tailoring onychomycosis therapy to individual patient characteristics, comorbidities, preferences, extent of nail involvement, and fungal species, such that physicians may optimize treatment outcomes, patient satisfaction, and safety.

Efficacy of topical trichloroacetic acid 100% either alone or combined with topical tioconazole 28% versus systemic itraconazole in the treatment of onychomycosis

BACKGROUND

Treatment of onychomycosis is still challenging and warrants the development of new treatment strategies. Different trials were conducted to increase the penetration and efficacy of topical antifungals aiming at finding an alternative treatment especially when systemic antifungals are contraindicated.

OBJECTIVES

To evaluate the efficacy of trichloroacetic acid (TCA) 100% either alone or combined with topical tioconazole 28% versus itraconazole pulse therapy in the treatment of onychomycosis.

PATIENTS/METHODS

Forty-five patients with onychomycosis were divided into three groups: group (A) treated by topical TCA 100% for 12 sessions, group (B) treated by TCA 100% for 12 sessions combined with topical tioconazole 28% for 18 weeks and group (C) treated by itraconazole (400 mg/day for 1 week/month for 4 months).

RESULTS

TCA 100% combined with topical tioconazole 28% showed the highest therapeutic response; however, the difference between the groups was statistically insignificant. Mycological cure (negative culture) was reported in 66.7% of group B versus 60% of group A and 40% of group C at the 20 week.

CONCLUSIONS

TCA 100% is an effective and safe treatment option for onychomycosis especially when combined with antifungals. This modality is promising in the treatment of onychomycosis especially with the increased resistance to different antifungals.

Effectiveness and safety of oral terbinafine for dermatophyte distal subungual onychomycosis

INTRODUCTION

Terbinafine has been a cornerstone in dermatophyte infection treatment. Despite its global efficacy, the emergence of terbinafine resistance raises concerns, requiring ongoing vigilance.

AREAS COVERED

This paper focuses on evaluating the efficacy and safety of terbinafine in treating dermatophyte toenail infections. Continuous and pulse therapies, with a 24-week continuous regimen and a higher dosage of 500 mg/day have demonstrated superior efficacy to the FDA approved regimen of 250 mg/day x 12 weeks. Pulse therapies, though showing comparable effectiveness, present debates with regards to their efficacy as conflicting findings have been reported. Safety concerns encompass hepatotoxicity, gastrointestinal, cutaneous, neurologic, hematologic and immune adverse-effects, and possible drug interactions, suggesting the need for ongoing monitoring.

EXPERT OPINION

Terbinafine efficacy depends on dosage, duration, and resistance patterns. Continuous therapy for 24 weeks and a dosage of 500 mg/day may enhance outcomes, but safety considerations and resistance necessitate individualized approaches. Alternatives, including topical agents and alternative antifungals, are to be considered for resistant cases. Understanding the interplay between treatment parameters, adverse effects, and resistance mechanisms is critical for optimizing therapeutic efficacy while mitigating resistance risks. Patient education and adherence are vital for early detection and management of adverse effects and resistance, contributing to tailored and effective treatments.

Efficacy of Terbinafine and Itraconazole Combination Therapy Versus Terbinafine or Itraconazole Monotherapy in the Management of Fungal Diseases: A Systematic Review and Meta-Analysis

Fungal infections constitute a common dermatological illness rampant in underdeveloped countries. Combination drug therapy is becoming increasingly well-established owing to drug resistance because of monotherapy. Different studies have been conducted previously to compare the medical regimens for the treatment of fungal infections. However, there is insufficient research on the difference in cure rates and recurrence rates with each regimen. To the best of our knowledge, this meta-analysis is the first to compare the effect of the most widely used oral antifungal medications and their combination usage. A meta-analysis of randomized controlled trials (RCTs) assesses the efficacy of terbinafine or itraconazole monotherapy versus combination therapy in fungal diseases. We queried PubMed and Cochrane Central from their inception to April 2022 for published studies, RCTs, and observational studies without any language restriction that compared itraconazole and terbinafine combination therapy with monotherapy in patients with fungal infections. The results from the studies were presented as risk ratios (RRs) with 95% confidence intervals (CIs) and were pooled using a random-effects model, and a p-value of ≤0.05 was considered significant for the analysis. Endpoints of interest included cure rates and recurrence rates. Cure rates were increased significantly for combination therapy compared to terbinafine monotherapy (RR=2.01 (1.37, 2.94); p=0.0003; I2=67%). On sensitivity analysis, a significant association was observed between combination therapy and itraconazole monotherapy in terms of cure rates (RR=1.91 (1.41, 2.57); p<0.0001; I2=0%) and recurrence rates (RR=0.08 (0.02, 0.44); p=0.003; I2=0%). The findings of this meta-analysis suggest that itraconazole and terbinafine combination therapy has a better cure rate when compared to terbinafine monotherapy.

Retrospective Analysis of Liver Enzyme Abnormalities in Patients Prescribed Terbinafine and Itraconazole for Onychomycosis

Introduction Onychomycosis (OM) is defined as a nail fungal infection. Its prevalence increases with advancing age. Human-to-human transmission makes it a serious public health risk. Although OM is not a life-threatening disease, it has a detrimental effect on patients' quality of life. Due to the long therapy duration and potential side effects of systemic antifungal medicines, physicians may be reluctant to treat OM orally. In this study, we aimed to evaluate the effect of terbinafine and itraconazole on liver transaminases, the side effects of these treatments, and patients' adherence to systemic treatment of OM. Methods This is a retrospective study conducted in our dermatology department (Ordu University, Ordu) between June 2020 and October 2021. Hospital records were analyzed, and patients with the diagnosis of tinea unguium (ICD code B35.1) were investigated. Patients who were prescribed terbinafine or itraconazole were included in the study. Following a clinical diagnosis of OM, the researchers first tried to confirm it through direct microscopic examination with potassium hydroxide (KOH). If the direct microscopic examination was negative but the suspicion about OM continued, confirmation was done through a fungal culture. Results This study included 735 patients, of whom 409 (55.6%) were female and 326 (44.4%) were male. The research covered all of the patients who were given one of these two medications. To find patients who could apply to other hospitals, the Turkish National Healthcare System was checked in addition to hospital information. To identify patients who could apply to other healthcare institutions, all hospitals share their data with this national healthcare system. Terbinafine was used by 433 patients (76.4%), 75 patients (13.2%), and 37 patients (6.5%), respectively, for one, two, and three months. A total of 119 patients (70.8%) took itraconazole for a month, 32 patients (19%) took it for two months, and four patients (2.33%) took it for three months. At the end of the first month, the proportion of the patients with elevated aspartate transaminase (AST) levels was 5.2% for terbinafine and 0% for itraconazole. Eighteen (8.4%) patients with terbinafine had elevated alanine aminotransferase (ALT) levels, and four patients (7.5%) who were on itraconazole treatment had high ALT levels. None of the patients reported cutaneous adverse drug reactions, gastrointestinal disturbances, or headaches due to OM treatment. Also, no patients discontinued treatment because of hepatotoxicity. Conclusion In this study, none of the patients discontinued the treatment because of hepatotoxicity. According to the results of this study, oral terbinafine and itraconazole can be used with close follow-up. Baseline and regular laboratory monitoring for AST and ALT should be done to monitor liver toxicity with terbinafine and itraconazole. Besides, we did not observe other side effects like cutaneous or cardiac side effects or drug-drug interactions.

The safety of oral antifungals for the treatment of onychomycosis

INTRODUCTION

Oral antifungals are used for the treatment of moderate-severe onychomycosis. Terbinafine and itraconazole are approved for onychomycosis treatment in North America; additionally, fluconazole is indicated for onychomycosis in Europe. Other oral antifungals such as ketoconazole and griseofulvin are no longer used for the treatment of onychomycosis due to safety concerns and relatively lower efficacy.

SEARCH STRATEGY

On 7 March 2023, we conducted a comprehensive search in PubMed and Google Scholar, while also manually examining selected article bibliographies and package inserts.

AREAS COVERED

Terbinafine, itraconazole, and fluconazole have several interactions with cytochrome-p450, and either alone, or when co-administered with other drugs these interactions can facilitate a multitude of adverse events. This article identifies possible hepatic, renal, cutaneous, cardiovascular, neurological, hemopoietic, and obstetric adverse events. We have also compared the rates of hepatotoxicity, clinically apparent liver injury, and alanine transaminase elevations between oral antifungals, and recommendations for hepatic monitoring.

EXPERT OPINION

We recommend laboratory testing of liver function tests prior to the administration of any oral antifungals, especially when clinically indicated. In the event of a first treatment failure, the diagnosis of onychomycosis must be confirmed, and consideration given to antifungal susceptibility testing. Antifungal stewardship will help reduce the incidence of antifungal resistance.

Risk Factors and Treatment Trends for Onychomycosis: A Case-Control Study of Onychomycosis Patients in the All of Us Research Program

Introda significant: Onychomycosis is the most common nail disorder seen in clinical practice, and it may have significant impact on patient quality of life. Understanding risk factors for onychomycosis may help to devise screening and treatment guidelines for populations that are more susceptible to this infection. Using a national database, we aimed to explore associations between onychomycosis and age, sex, and underlying medical conditions, as well as to examine current onychomycosis treatment trends. Materials and Methods: We performed a nested, matched, case-control study of patients in the All of Us database aged ≥ 18 years (6 May 2018-1 January 2022). Onychomycosis cases were identified using International Classification of Diseases (ICD) and Systematized Nomenclature of Medicine (SNOMED) diagnostic codes (ICD-9 110.1, ICD-10 B35.1, SNOMED 414941008). Demographic information (i.e., age, sex, and race), treatments, and co-diagnoses for onychomycosis patients and case-controls were recorded. Wald's test applied to multivariate logistic regression was used to calculate odds ratios and p-values between onychomycosis and co-diagnoses. Additionally, 95% confidence intervals were calculated with a proportion test. Results: We included 15,760 onychomycosis patients and 47,280 matched controls. The mean age of onychomycosis patients was 64.9 years, with 54.2% female, 52.8% Non-Hispanic White, 23.0% Black, 17.8% Hispanic, and 6.3% other, which was similar to controls. Patients with onychomycosis vs. controls were more likely to have a co-diagnosis of obesity (46.4%, OR 2.59 [2.49-2.69]), tinea pedis (21.5%, OR 10.9 [10.1-11.6]), peripheral vascular disease (PVD) (14.4%, OR 3.04 [2.86-3.24]), venous insufficiency (13.4%, OR 3.38 [3.15-3.59]), venous varices (5.6%, OR 2.71 [2.47-2.97]), diabetes mellitus (5.6%, OR 3.28 [2.98-3.61]), and human immunodeficiency virus (HIV) (3.5%, OR 1.8 [1.61-2.00]) (p < 0.05, all). The most frequently prescribed oral and topical medications were terbinafine (20.9%) and ciclopirox (12.4%), respectively. The most common therapeutic procedure performed was debridement (19.3%). Over the study period, ciclopirox prescriptions (Spearman correlation 0.182, p = 0.0361) and fluconazole prescriptions increased (Spearman correlation 0.665, p = 2.44 × 10^-4), and griseofulvin (Spearman correlation -0.557, p = 0.0131) and itraconazole prescriptions decreased (Spearman correlation -0.681, p = 3.32 × 10^-6). Conclusions: Our study demonstrated that age, obesity, tinea pedis, PVD, venous insufficiency, diabetes mellitus, and HIV were significant risk factors for onychomycosis. In addition, the most frequent oral and topical onychomycosis medications prescribed were terbinafine and ciclopirox, likely reflective of efficacy and cost considerations. Identifying and managing these risk factors is essential to preventing onychomycosis' primary infections and recurrences and improving treatment efficacy.

Membranolytic Activity Profile of Nonyl 3,4-Dihydroxybenzoate: A New Anti-Biofilm Compound for the Treatment of Dermatophytosis

The ability of dermatophytes to live in communities and resist antifungal drugs may explain treatment recurrence, especially in onychomycosis. Therefore, new molecules with reduced toxicity that target dermatophyte biofilms should be investigated. This study evaluated nonyl 3,4-dihydroxybenzoate (nonyl) susceptibility and mechanism of action on planktonic cells and biofilms of T. rubrum and T. mentagrophytes. Metabolic activities, ergosterol, and reactive oxygen species (ROS) were quantified, and the expression of genes encoding ergosterol was determined by real-time PCR. The effects on the biofilm structure were visualized using confocal electron microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). T. rubrum and T. mentagrophytes biofilms were susceptible to nonyl and resistant to fluconazole, griseofulvin (all strains), and terbinafine (two strains). The SEM results revealed that nonyl groups seriously damaged the biofilms, whereas synthetic drugs caused little or no damage and, in some cases, stimulated the development of resistance structures. Confocal microscopy showed a drastic reduction in biofilm thickness, and transmission electron microscopy results indicated that the compound promoted the derangement and formation of pores in the plasma membrane. Biochemical and molecular assays indicated that fungal membrane ergosterol is a nonyl target. These findings show that nonyl 3,4-dihydroxybenzoate is a promising antifungal compound.

Expanding Family Health History to Include Family Medication History

The collection of family health history (FHH) is an essential component of clinical practice and an important piece of data for patient risk assessment. However, family history data have generally been limited to diseases and have not included medication history. Family history was a key component of early pharmacogenetic research, confirming the role of genes in drug response. With the substantial number of known pharmacogenes, many affecting response to commonly prescribed medications, and the availability of clinical pharmacogenetic (PGx) tests and guidelines for interpretation, the collection of family medication history can inform testing decisions. This paper explores the roots of family-based pharmacogenetic studies to confirm the role of genes in these complex phenotypes and the benefits and challenges of collecting family medication history as part of family health history intake.

Allylamines, Benzylamines, and Fungal Cell Permeability: A Review of Mechanistic Effects and Usefulness against Fungal Pathogens

Allylamines, naftifine and terbinafine, and the benzylamine, butenafine, are antifungal agents with activity on the fungal cell membrane. These synthetic compounds specifically inhibit squalene epoxidase, a key enzyme in fungal sterol biosynthesis. This results in a deficiency in ergosterol, a major fungal membrane sterol that regulates membrane fluidity, biogenesis, and functions, and whose damage results in increased membrane permeability and leakage of cellular components, ultimately leading to fungal cell death. With the fungal cell membrane being predominantly made up of lipids including sterols, these lipids have a vital role in the pathogenesis of fungal infections and the identification of improved therapies. This review will focus on the fungal cell membrane structure, activity of allylamines and benzylamines, and the mechanistic damage they cause to the membrane. Furthermore, pharmaceutical preparations and clinical uses of these drugs, mainly in dermatophyte infections, will be reviewed.

Updated Perspectives on the Diagnosis and Management of Onychomycosis

Onychomycosis is the most common nail disease encountered in clinical practice and can cause pain, difficulty with ambulation, and psycho-social problems. A thorough history and physical examination, including dermoscopy, should be performed for each patient presenting with nail findings suggestive of onychomycosis. Several approaches are available for definitive diagnostic testing, including potassium hydroxide and microscopy, fungal culture, histopathology, polymerase chain reaction, or a combination of techniques. Confirmatory testing should be performed for each patient prior to initiating any antifungal therapies. There are several different therapeutic options available, including oral and topical medications as well as device-based treatments. Oral antifungals are generally recommended for moderate to severe onychomycosis and have higher cure rates, while topical antifungals are recommended for mild to moderate disease and have more favorable safety profiles. Oral terbinafine, itraconazole, and griseofulvin and topical ciclopirox 8% nail lacquer, efinaconazole 10% solution, and tavaborole 5% solution are approved by the Food and Drug Administration for treatment of onychomycosis in the United States and amorolfine 5% nail lacquer is approved in Europe. Laser treatment is approved in the United States for temporary increases in clear nail, but clinical results are suboptimal. Oral fluconazole is not approved in the United States for onychomycosis treatment, but is frequently used off-label with good efficacy. Several novel oral, topical, and over-the-counter therapies are currently under investigation. Physicians should consider the disease severity, infecting pathogen, medication safety, efficacy and cost, and patient age, comorbidities, medication history, and likelihood of compliance when determining management plans. Onychomycosis is a chronic disease with high recurrence rates and patients should be counseled on an appropriate plan to minimize recurrence risk following effective antifungal therapy.

Development and research progress of anti-drug resistant fungal drugs

With the widespread use of immunosuppressive agents and the increase in patients with severe infections, the incidence of fungal infections worldwide has increased year by year. The fungal pathogens Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus cause a total of more than 1 million deaths each year. Long-term use of antifungal drugs can easily lead to fungal resistance, and the prevalence of drug-resistant fungi is a major global health challenge. In order to effectively control global fungal infections, there is an urgent need for new drugs that can exert effective antifungal activity and overcome drug resistance. We must promote the discovery of new antifungal targets and drugs, and find effective ways to control drug-resistant fungi through different ways, so as to reduce the threat of drug-resistant fungi to human life, health and safety. In the past few years, certain progress has been made in the research and development of antifungal drugs. In addition to summarizing some of the antifungal drugs currently approved by the FDA, this review also focuses on potential antifungal drugs, the repositioned drugs, and drugs that can treat drug-resistant bacteria and fungal infections, and provide new ideas for the development of antifungal drugs in the future.

Efficacy of laser therapy combined with topical antifungal agents for onychomycosis: a systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

Onychomycosis is a common fungal infection of the nail. Laser and topical antifungal agent combination therapy is an emerging treatment for onychomycosis. The objective of this study was to systematically evaluate the efficacy and safety of laser and topical antifungal agent combination therapy for onychomycosis.

METHODS

The PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang and VIP databases were searched from inception to November 2021. Randomised controlled trials (RCTs) on laser therapy combined with topical antifungal agents for onychomycosis were included. The Cochrane Collaboration tool was used to assess the risk of bias, and Revman 5.3 software was used in the meta-analysis.

RESULTS

Twelve studies involving 869 patients were included in this meta-analysis. The results showed that compared with topical antifungal agents alone, laser and topical antifungal agent combination therapy was superior in terms of the complete cure rate (RR 6.04,95% CI (2.17, 16.85), P = 0.0006), mycological cure rate (RR 1.27, 95% CI (1.10, 1.48), P = 0.001), clinical effective rate (RR 1.38, 95% CI (1.20, 1.57), P < 0.00001) and patient satisfaction rate (RR 1.47,95% CI (1.17, 1.84), P = 0.0009).The subgroup analysis of outcome indicators, including mycological cure rate and clinical effective rate, demonstrated that both carbon dioxide (CO₂) laser therapy combined with topical antifungal therapy and 1064-nm neodymium-doped:yttrium aluminium garnet (Nd:YAG) laser therapy combined with topical antifungal therapy showed better results than topical antifungal therapy alone. No adverse events were identified except for three studies reporting transient burning sensation without treatment and mild to moderate pain, both of which were well tolerated.

CONCLUSION

The present study indicated that laser and topical antifungal agent combination therapy is effective for onychomycosis. However, more large-scale and well-designed RCTs are warranted.

Assessment of the Clinical Diagnosis of Onychomycosis by Dermoscopy

Background

As a common clinical superficial fungal infection, the diagnosis of onychomycosis relies on clinical features, traditional KOH direct microscopy and fungal culture. In recent years, dermoscopy has been widely used in the diagnosis and treatment of infectious diseases and has provided new options for the diagnosis of onychomycosis.

Objective

To evaluate the value of dermoscopy in the clinical diagnosis of onychomycosis and to explore the relationship between each clinical subtype and the dermoscopic pattern.

Methods

A retrospective study of 114 cases of clinically suspected onychomycosis was conducted to compare the differences between dermoscopy and fungal pathogenic examination (microscopy and culture) in the diagnostic sensitivity of onychomycosis and to analyze the relationship between nine common dermoscopic modalities and clinical subtypes of onychomycosis.

Results

Among the 114 proposed patients, 87 nails with positive fluorescent staining microscopy and/or positive fungal cultures were diagnosed as onychomycosis. The sensitivity and specificity of dermatoscopy, using the mycological findings as a reference, were 86.21 and 33.33%, respectively. The incidence of common dermatoscopic patterns in the 87 nails with confirmed onychomycosis was as follows: white flocculation in 76 cases (87.35%), longitudinal nail pattern in 72 cases (82.76%), jagged changes in the distal nail plate in 69 cases (79.31%) and yellow staining in 46 cases (52.87%), these four patterns were more commonly seen in the distal lateral subungual onychomycosis and total dystrophic onychomycosis, but there was no statistical difference in the positive dermatoscopic pattern between these two types (P > 0.05).

Conclusion

Dermoscopy can be an important aid in the diagnosis of onychomycosis, especially when fungal microscopy or culture is not appropriate, but this method is still not a substitute for fungal microscopy and culture.

Combination Therapy Should Be Reserved as Second-Line Treatment of Onychomycosis: A Systematic Review of Onychomycosis Clinical Trials

Onychomycosis is the most common nail disease encountered in clinical practice. Its importance extends well beyond aesthetics, often causing pain, difficulty with ambulation and performing daily activities, and impairing quality of life. Many patients fail to achieve cure with antifungal monotherapy and recurrences are common. Combination therapy has therefore gained considerable interest, given the potential for drug synergy and prevention of antifungal resistance, but it has not been well studied. A systematic review of onychomycosis medication only, as well as medication and procedural (laser, debridement, photodynamic therapy), clinical or randomized controlled trials evaluating combination vs. monotherapies was performed. After exclusions, 30 studies were included in the final analysis. There were conflicting results for medication-only trials, with some showing significant benefit of combination therapy over monotherapy, however, trials were not robustly designed and lacked sufficient follow-up. Procedural studies also lacked long-term follow-up, and failed to demonstrate efficacy in some severe onychomycosis cases. Considering the high cure rates demonstrated in pivotal antifungal monotherapy trials, and conflicting results, costs, and safety concerns associated with combination therapy, we recommend that combination therapy be reserved as second-line treatment options in patients with poor prognostic factors or for those who failed monotherapy for onychomycosis.

Cold atmospheric pressure plasma (CAPP) as a new alternative treatment method for onychomycosis caused by Trichophyton verrucosum: in vitro studies

PURPOSE

Anthropophilic dermatophytes as etiological factors of onychomycoses are more common than zoophilic fungi. In the case of the latter, reverse zoonoses are possible, which poses a threat to the persistence of dermatophytes in the environment. Nevertheless, without treatment, both types of tinea unguium may lead to complete nail plate destruction and secondary mixed infections with fungi and bacteria. One of the zoophilic dermatophytes that cause onychomycosis is Trichophyton verrucosum, whose prevalence has been increasing in recent years. Such infections are usually treated with allylamines and/or azoles, but such a conventional treatment of infections caused by T. verrucosum often fails or is discontinued by patients.

METHODS

Herein, we reveal the results of our in vitro studies related to direct application of cold atmospheric pressure plasma (CAPP) on Trichophyton verrucosum growth, germination and adherence to nail as a new alternative treatment method of such types of dermatomycoses.

RESULTS

Our in vitro studies showed that, while exposure to CAPP for 10 min delays germination of conidia and clearly impairs the fitness of the fungal structures, 15 min is enough to kill all fungal elements exposed to plasma. Moreover, the SEM images revealed that T. verrucosum cultures exposed to CAPP for 10 and 15 min were not able to invade the nail fragments.

CONCLUSION

The results revealed that single exposure to CAPP was able to inhibit T. verrucosum growth and infection capacity. Hence, cold atmospheric pressure plasma should be considered as a promising alternative treatment of onychomycoses.

Molecular identification and antifungal susceptibility of 75 clinical isolates of Trichophyton spp. from southern Brazil

BACKGROUND

Dermatophytoses affect more than 20% of the world's population and is caused by filamentous fungi, mainly of the genus Trichophyton. The species identification through microscopic direct examination and culture methods is challenging, with molecular presenting high sensitivity and specificity. Although there are several therapy options for dermatophyte infections, treatment failures and antifungal resistance are growing concerns.

OBJECTIVE

This study aimed to identify clinical isolates of Trichophyton spp. from southern Brazil using molecular methods and determine their in-vitro antifungal susceptibility.

MATERIAL AND METHODS

Seventy-five isolates were identified through sequencing of the ITS region. The exposure to seven antifungals drugs was performed according to protocol M28-A2 of the Clinical and Laboratory Standards Institute (CLSI).

RESULTS

Sixty-one isolates (81%) were identified as T. interdigitale, which differs from the epidemiological data present in the literature. Thirteen isolates were identified as T. rubrum and one as T. tonsurans. Terbinafine was the most effective antifungal, followed by itraconazole and voriconazole, which is in accordance with the results reported in previous studies.

CONCLUSIONS

The use of molecular methods to identify Trichophyton spp. clinical isolates and the performance of susceptibility tests are relevant to epidemiological data, identification of the emergence of antifungal resistance, and to help to translate the in-vitro antifungal susceptibility results into clinical practice.

Combined laser and ozone therapy for onychomycosis in an in vitro and ex vivo model

In order to develop a fast combined method for onychomycosis treatment using an in vitro and an ex vivo models, a combination of two dual-diode lasers at 405 nm and 639 nm wavelengths, in a continuous manner, together with different ozone concentrations (until 80 ppm), was used for performing the experiments on fungal strains growing on PDA agar medium or on pig’s hooves samples. In the in vitro model experiments, with 30 min combined treatment, all species are inhibited at 40 ppm ozone concentration, except S. brevicaulis, which didn’t show an inhibition in comparison with only ozone treatment. In the ex vivo model experiments, with the same duration and ozone concentration, A. chrysogenum and E. floccosum showed total inhibition; T. mentagrophytes and T. rubrum showed a 75% growth inhibition; M. canis showed a delay in sporulation; and S. brevicaulis and A. terreus did not show growth inhibition. This combined laser and ozone treatment may be developed as a fast therapy for human onychomycosis, as a potential alternative to the use of antifungal drugs with potential side effects and long duration treatments.