A large-scale North American study of fungal isolates from nails: the frequency of onychomycosis, fungal distribution, and antifungal susceptibility patterns

Novel in vivo observations of luliconazole 5% nail solution for onychomycosis: An ultrastructural study

Lesional nails of 10 patients with onychomycosis (tinea unguium) were investigated by transmission electron microscopy (TEM) to gain an insight into in vivo morphological changes of dermatophytes after application of a clinical dosage of topical luliconazole (LLCZ) 5% nail solution. In these cases, Trichophyton rubrum (T. rubrum) was identified in three cases and T. interdigitale was identified in four cases (three unidentified cases; we were unable to identify either the genus or species). Specimens from tinea unguium before and after topical LLCZ application (maximum of 14 days) were observed by TEM. Two types of morphological changes of hyphae were revealed. Intracytoplasmic degeneration without antecedent obvious changes in the cell wall (type 1 degeneration) and degeneration of the fungal cell wall preceding intracytoplasmic changes (type 2 degeneration) were observed. We also examined in vivo morphological changes of dermatophytes in tinea pedis treated with ketoconazole (KCZ) to compare the morphological changes in the cell wall, plasma membrane, and cytoplasm to those after the application of LLCZ. Intracytoplasmic degeneration (type 1 degeneration) was observed in tinea pedis scales treated with topical KCZ. We confirmed that topical LLCZ 5% nail solution had acting points on the plasma membrane, cell wall, and cytoplasm of dermatophyte hyphae and that various degrees of morphological changes in lesional nails of tinea unguium occurred during treatment with topical LLCZ 5% nail solution.

Multidrug-resistant keratinolytic dermatophytes and non-dermatophytes causing onychomycosis in outpatients

AIMS

This study identified and determined antibiograms of keratinolytic dermatophytes (DM), non-dermatophytic molds (NDM), and yeasts causing onychomycosis.

METHODS

Morphological, cultural, and biochemical characteristics were used to identify DM and NDM. The keratinolytic activity (KA) and antibiograms were conducted with keratin azure and the agar diffusion method, respectively. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined using the microdilution method.

RESULTS

Onychomycosis was more prevalent in males (53%) than females, toenails (57%) than fingernails, and commercial employees (40%) than other employees or unemployed. Fungal growth was observed in 92.5% nail samples. DM, NDM, and yeasts caused 46%, 35%, and 19% onychomycosis, respectively. Trichophyton rubrum and Trichophyton mentagrophytes were the common DM. Five different genus of NDM and three different yeasts were isolated. The KA of DM was 30-45% higher than that of NDM and yeasts. All fungal isolates (FI) were resistant to griseofulvin and fluconazole. However, 71%, 64%, and 36% of FI were sensitive to terbinafine hydrochloride, nystatin, and ketoconazole, respectively, while 84% of DM and 46% of NDM were multidrug-resistant. The MIC and MFC of these antifungals against FI ranged from micrograms to milligrams.

CONCLUSION

Multidrug resistance is growing in keratinolytic DM and NDM.

Tinea manuum: a 5 year retrospective study of demographic data, clinical characteristics, and treatment outcomes

Tinea manuum is a superficial fungal infection affecting the hands, particularly the palms and interdigital areas. This retrospective study investigated clinical features, laboratory findings, treatment, and outcomes in patients with fungal hand infections at Siriraj Hospital between 2016 and 2020. Among 107 patients, representing 1.3% of those with fungal skin infections, 64.5% were male, with a mean age of 54.3 ± 18.5 years. Diabetes mellitus was present in 26.2%, and 23.4% had prior topical steroid use. The most common symptom was itching (75.7%), while palm-scale (85.9%) was the most prevalent clinical finding. Concurrent fingernail onychomycosis was observed in 43%, and 59.8% had additional fungal skin infections. Among 50 positive cultures, dermatophytes accounted for 86% and nondermatophytes for 14%, with Trichophyton rubrum (54%) and Trichophyton mentagrophytes complex (24%) being the most frequent pathogens. Systemic antifungal treatment was administered to 57% of patients, with a mycological cure rate of 56.4%. A complete cure was achieved in 60.5% of dermatophyte infections but in none of the nondermatophyte cases (p = 0.003). These findings highlighted that tinea manuum could be caused by both dermatophytes and nondermatophytes, with significantly poorer outcomes observed in nondermatophyte infections. Concurrent fungal skin and nail infections should be evaluated for optimal management.

Structure-activity relationship studies of ME1111, a novel antifungal agent for topical treatment of onychomycosis

Onychomycosis is a prevalent disease in many areas of the world, affecting approximately 5.5% of the global population. Among several subtypes of onychomycosis, distal-lateral-subungual onychomycosis is the most common, and topical onychomycosis agents effective against this pathogenesis require properties such as high nail penetration and low affinity for keratin, the main component of the nail. To develop novel and highly effective antifungal agents with such properties, we first established an efficient ex vivo evaluation method using bovine hoof slices and human nails, and then used this method to screen an in-house compound library. Using this strategy, we identified 1, a structure with a phenyl-pyrazole skeleton. In subsequent analyses, we investigated the structure-activity relationship of 1, permitting the identification of 28 (Development Code ME1111).

Epidemiology of Onychomycosis in the United States Characterized Using Molecular Methods, 2015-2024

Onychomycosis is a recalcitrant fungal infection of the nail unit that can lead to secondary infections and foot complications. Accurate pathogen identification by confirmatory testing is recommended to improve treatment outcomes. In this study, we reviewed the records of 710,541 patients whose nail specimens were sent to a single molecular diagnostic laboratory between 2015 and 2024. PCR testing revealed a more comprehensive spectrum of pathogens than previously reported, which was corroborated by the demonstration of fungal invasion on histopathology. Consistent with our current understanding, the T. rubrum complex (54.3%) are among the most common pathogens; however, a significant portion of mycology-confirmed diagnoses were caused by the T. mentagrophytes complex (6.5%), Aspergillus (7.0%) and Fusarium (4.5%). Females were significantly more likely to be infected with non-dermatophytes molds (NDMs; OR: 2.0), including Aspergillus (OR: 3.3) and Fusarium (OR: 2.0), and yeasts (OR: 1.5), including Candida albicans (OR: 2.0) and C. parapsilosis (OR 1.6), than males. The T. mentagrophytes complex became more prevalent with age, and conversely the T. rubrum complex became less prevalent with age. Patients aged ≥65 years also demonstrated a higher likelihood of contracting onychomycosis caused by NDMs (OR: 1.6), including Aspergillus (OR: 2.2), Acremonium (OR: 3.5), Scopulariopsis (OR: 2.9), Neoscytalidium (OR: 3.8), and yeasts (OR: 1.8), including C. albicans (OR: 1.9) and C. parapsilosis (OR: 1.7), than young adults. NDMs (e.g., Aspergillus and Fusarium) and yeasts were, overall, more likely to cause superficial onychomycosis and less likely to cause dystrophic onychomycosis than dermatophytes. With regards to subungual onychomycosis, Aspergillus, Scopulariopsis and Neoscytalidium had a similar likelihood as dermatophytes. The advent of molecular diagnostics enabling a timely and accurate pathogen identification can better inform healthcare providers of appropriate treatment selections and develop evidence-based recommendations.

New Sources of Resistance to Terbinafine Revealed and Squalene Epoxidase Modelled in the Dermatophyte Fungus Trichophyton interdigitale From Australia

BACKGROUND

Terbinafine is widely used to treat onychomycosis caused by dermatophyte fungi. Terbinafine resistance in recent years is causing concern. Resistance has so far been associated with single-nucleotide substitutions in the DNA sequence of the enzyme squalene epoxidase (SQLE) but how this affects SQLE functionality is not understood.

OBJECTIVES

The aim of this study was to understand newly discovered resistance in two Australian strains of Trichophyton interdigitale.

PATIENTS/METHODS

Resistance to terbinafine was tested in four newly isolated strains. Three-dimensional SQLE models were prepared to investigate how the structure of their SQLE affected the binding of terbinafine.

RESULTS

This study found the first Australian occurrences of terbinafine resistance in two T. interdigitale strains. Both strains had novel deletion mutations in erg1 and frameshifts during translation. Three-dimensional models had smaller SQLE proteins and open reading frames as well as fewer C-terminal α-helices than susceptible strains. In susceptible strains, the lipophilic tail of terbinafine was predicted to dock stably into a hydrophobic pocket in SQLE lined by over 20 hydrophobic amino acids. In resistant strains, molecular dynamics simulations showed that terbinafine docking was unstable and so terbinafine did not block squalene metabolism and ultimately ergosterol production. The resistant reference strain ATCC MYA-4438 T. rubrum showed a single erg1 mutation that resulted in frameshift during translation, leading to C-terminal helix deletion.

CONCLUSIONS

Modelling their effects on their SQLE proteins will aid in the design of potential new treatments for these novel resistant strains, which pose clinical problems in treating dermatophyte infections with terbinafine.

Antidermatophyte activity and PK/PD of ME1111 in a guinea pig model of tinea corporis

Onychomycosis, a superficial fungal infection of the nails, is prevalent in many areas of the world. Topical agents for onychomycosis need to reach the subungual layer and nail bed to exert antifungal activity in the presence of keratin, the major component of the nail. It is difficult to evaluate the efficacy and pharmacodynamics of topical agents for onychomycosis in a non-clinical evaluation system. No consistent animal model has yet been established to predict the efficacy of topical agents for onychomycosis. In this study, we evaluated the pharmacokinetics and pharmacodynamics of ME1111 in a guinea pig model of tinea corporis designed to predict the efficacy of topical medication for onychomycosis in the vicinity of the nail bed. Trichophyton mentagrophytes TIMM1189 was infected on the back skin of guinea pigs, and ME1111 solution (5%, 10%, or 15%) was administered topically, once daily for 14 consecutive days. Following the completion of dosing, segments of skin from the site of infection were excised and cultured. The concentration of ME1111 in the back skin of guinea pigs increased with formulation concentration and correlated with mycological efficacy. We revealed the concentration required for ME1111 to be effective at the site of infection. Further analysis is needed to predict the efficacy of topical agents for onychomycosis by analyzing the relationship between PK/PD around the nail bed and factors such as subungual penetration and permeability.

New Diagnostic Strategy for Onychomycosis: First-Line Utilization of DermaGenius® PCR and Calcofluor Microscopy Combined with Selective Culturing

Onychomycosis (OM) is a widespread infection requiring prolonged treatment with potential side effects. Diagnostic certainty is therefore essential before initiating antifungal therapy. Molecular biology has already shown benefits in reducing the time to diagnosis, providing technical ease, and increasing sensitivity for the respective species that molecular tests can detect. Nevertheless, causative agents are numerous, and culture remains essential, particularly for detecting non-dermatophytes mold infections. This study compared the performance of three different diagnostic strategies: conventional culture technique, the multiplex DermaGenius® 2.0 PCR (DG), and a mixed PCR/culture algorithm guided by the result of direct examination with calcofluor (DEC). The mixed algorithm (MA) prioritizes DG PCR and DEC as the primary diagnostic tools, supplemented by selective sample inoculation when mycelial elements are visualized in DEC and when DG PCR fails to detect any fungus or identifies a fungus with morphology differing from that observed in DEC (filamentous fungi versus yeasts). With only 13% of samples requiring inoculation, MA emerged as the most effective strategy, demonstrating significantly higher sensitivity (98.18%; p < 0.001) compared to single-method approaches (78.18% for DG PCR alone and 74.55% for culture alone) while maintaining a specificity comparable to DG PCR (100%). This new approach saves time in result delivery, requires fewer human resources, and increases diagnostic accuracy to better meet the needs of clinicians.

Potential emergence of terbinafine resistance by squalene epoxidase gene mutations: An 18-month cohort study of onychomycosis patients in the United States

BACKGROUND

There is a concerning rise in antifungal-resistant dermatophytosis globally, with resistance to terbinafine conferred by point mutations in the squalene epoxidase (SQLE) gene.

OBJECTIVES

Report changes in the prevalence and profile of SQLE mutations in onychomycosis patients in the United States.

METHODS

A longitudinal cohort study of toenail samples was collected from suspected onychomycosis patients over an 18-month period from 2022 to 2023. Samples were submitted from across the United States and subjected to multiplex real-time polymerase chain reactions for dermatophyte detection, with further screening of SQLE mutations at four known hotspots (393Leu, 397Phe, 415Phe and 440His).

RESULTS

A total of 62,056 samples were submitted (mean age: 57.5 years; female: 60.4%). Dermatophytes were detected in 38.5% of samples, primarily Trichophyton rubrum complex (83.6%) and T. mentagrophytes complex (10.7%). A survey of SQLE mutations was carried out in 22,610 dermatophyte samples; there was a significant increase in the prevalence of SQLE mutations between the first quarter of 2022 and the second quarter of 2023 (29.0 to 61.9 per 1000 persons). The Phe397Leu substitution was the predominant mutation; Phe415Ser and His440Tyr have also emerged which were previously reported as minor mutations in skin samples. The temporal change in mutation rates can be primarily attributed to the Phe415Ser substitution. Samples from elderly patients (>70 years) are more likely to be infected with the T. mentagrophytes complex including strains harbouring the Phe415Ser substitution.

CONCLUSION

The prevalence of SQLE mutations among onychomycosis patients with Trichophyton infections may be underestimated. Older individuals may have a higher risk.

Safety and efficacy of new generation azole antifungals in the management of recalcitrant superficial fungal infections and onychomycosis

INTRODUCTION

Terbinafine is considered the gold standard for treating skin fungal infections and onychomycosis. However, recent reports suggest that dermatophytes are developing resistance to terbinafine and the other traditional antifungal agents, itraconazole and fluconazole. When there is resistance to terbinafine, itraconazole or fluconazole, or when these agents cannot used, for example, due to potential drug interactions with the patient's current medications, clinicians may need to consider off-label use of new generation azoles, such as voriconazole, posaconazole, fosravuconazole, or oteseconazole. It is essential to emphasize that we do not advocate the use of newer generation azoles unless traditional agents such as terbinafine, itraconazole, or fluconazole have been thoroughly evaluated as first-line therapies.

AREAS COVERED

This article reviews the clinical evidence, safety, dosage regimens, pharmacokinetics, and management algorithm of new-generation azole antifungals.

EXPERT OPINION

Antifungal stewardship should be the top priority when prescribing new-generation azoles. First-line antifungal therapy is terbinafine and itraconazole. Fluconazole is a consideration but is generally less effective and its use may be off-label in many countries. For difficult-to-treat skin fungal infections and onychomycosis, that have failed terbinafine, itraconazole and fluconazole, we propose consideration of off-label voriconazole or posaconazole.

Antifungal Activity of Aniba canelilla (Kunth) Mez Essential Oil and Its Main Compound 1-Nitro-2-Phenylethane against Dermatophytes

The essential oil of Aniba canelilla (Kunth) Mez (EOAC), an Amazon plant composed of a rare nitro compound, has shown scientific evidence of antifungal activity but is still unexplored against dermatophytes. The antifungal susceptibility of EOAC and its main compound, 1-nitro-2-phenylethane (NP), was evaluated against dermatophytes (Trichophyton rubrum, T. mentagrophytes and Microsporum canis), evidencing antifungal activity with an inhibitory concentration lower than 256 μg/mL. The mechanism of action was also evaluated, and it is suggested that EOAC and NP have fungicidal action in the fungal membrane, since the antifungal activity occurs through a modification of the shape of the conidial structures of the fungus, showing the permeability of the intracellular content due to the visually observed plasmolysis and cytosolic extravasation through an osmotic process. These results suggest the essential oil and its main compound are promising plant-derived alternatives for treating ungual dermatophytosis.

Time to Think Antifungal Resistance Increased Antifungal Resistance Exacerbates the Burden of Fungal Infections Including Resistant Dermatomycoses

Increased antifungal resistance is exacerbating the burden of invasive fungal infections, as well as potentially contributing to the increase in resistant dermatomycoses. In this commentary, we focus on antifungal drug resistance, in contrast to antibacterial resistance. We provide a brief historical perspective on the emergence of antifungal resistance and propose measures for combating this growing health concern. The increase in the incidence of invasive and cutaneous fungal infections parallels advancements in medical interventions, such as immunosuppressive drugs, to manage cancer and reduce organ rejection following transplant. A disturbing relatively new trend in antifungal resistance is the observation of several fungal species that now exhibit multidrug resistance (eg, Candida auris, Trichophyton indotineae). Increasing awareness of these multidrug-resistant species is paramount. Therefore, increased education regarding potential fungus-associated infections is needed to address awareness in the general healthcare setting, which may result in a more realistic picture of the prevalence of antifungal-resistant infections. In addition to education, increased use of diagnostic tests (eg, micro and macro conventional assays or molecular testing) should be routine for healthcare providers facing an unknown fungal infection. Two critical barriers that affect the low rates for Antifungal Susceptibility Testing (AST) are low (or a lack of) sufficient insurance reimbursement rates and the low number of qualified laboratories with the capacity to perform AST. The ultimate aim is to improve the quality of patient care through fungal identification, diagnosis, and, where appropriate, susceptibility testing. Here we propose an all-encompassing call to action to address this emerging challenge.

A comprehensive review of nondermatophyte mould onychomycosis: Epidemiology, diagnosis and management

Nondermatophyte moulds (NDMs) are widely distributed and can be detected in association with mycotic nails; however, sometimes it can be challenging to establish the role of NDMs in the pathogenesis of onychomycosis (i.e. causative vs. contaminant). In studies where the ongoing invasive presence of NDMs is confirmed through repeat cultures, the global prevalence of NDMs in onychomycosis patients is estimated at 6.9% with the 3 most common genus being: Aspergillus, Scopulariopsis and Fusarium. NDM onychomycosis can, in many cases, appear clinically indistinguishable from dermatophyte onychomycosis. Clinical features suggestive of NDMs include proximal subungual onychomycosis with paronychia associated with Aspergillus spp., Fusarium spp. and Scopulariopsis brevicaulis, as well as superficial white onychomycosis in a deep and diffused pattern associated with Aspergillus and Fusarium. Longitudinal streaks seen in patients with distal and lateral onychomycosis may serve as an additional indicator. For diagnosis, light microscopic examination should demonstrate fungal filaments consistent with an NDM with at least two independent isolations in the absence of a dermatophyte; the advent of molecular testing combined with histological assessment may serve as an alternative with improved sensitivity and turnover time. In most instances, antifungal susceptibility testing has limited value. Information on effective treatments for NDM onychomycosis is relatively scarce, unlike the situation in the study of dermatophyte onychomycosis. Terbinafine and itraconazole therapy (continuous and pulsed) appear effective to varying extents for treating onychomycosis caused by Aspergillus, Fusarium or Scopulariopsis. There is scant literature on oral treatments for Neoscytalidium.

Clinical Diagnosis and Laboratory Testing of Abnormal Appearing Toenails: A Retrospective Assessment of Confirmatory Testing for Onychomycosis in the United States, 2022-2023

Onychomycosis is an under-recognized healthcare burden. Despite the risk of misdiagnosis, confirmatory laboratory testing is under-utilized. Histopathologic examination with polymerase chain reaction (PCR) is currently the most effective diagnostic method; it offers direct detection and identification of a fungal invasion. In this retrospective cohort study, we assessed confirmatory testing results, with matching clinical diagnoses, in 96,293 nail specimens submitted during a 9-month period from 2022 to 2023. Toenail specimens were examined using fungal culture, histopathology and/or PCR. Clinical diagnoses were identified using the International Classification of Diseases 10th Revision codes. For clinically diagnosed onychomycosis patients, the overall positivity rate was 59.4%; a similar positivity rate (59.5%) was found in patients with clinically diagnosed non-fungal nail dystrophy. Performing a histopathologic examination with PCR was more likely to provide pathogen identification results than using fungal culture. Male patients had a higher rate of onychomycosis overall; however, female patients had more non-dermatophyte mold onychomycosis caused by Aspergillus. Clinically diagnosed onychomycosis patients with a co-diagnosis of tinea pedis were more likely to test positive for onychomycosis by PCR (odds ratio [OR]: 4.2; 95% confidence interval [CI]: 2.7-6.4), histopathology (OR: 2.5; 95% CI: 2.0-3.1) and fungal culture (OR: 3.2; 95% CI: 1.5-6.6). Our results support the use of confirmatory laboratory testing when there is a clinical diagnosis of onychomycosis.

Determination of Efinaconazole in Plasma using Validated LC-MS/MS Technique

BACKGROUND

Efinaconazole is a topical antifungal medication that is effective against fungal infections of the toenails. In addition, due to its application on the skin, minimal systemic absorption takes place on the epidermic layer, which leads to the availability of lower-level concentration in the bloodstream. Although several reported methods in the literature describe the quantification of Efinaconazole using conventional techniques like HPTLC and HPLC, these methods lack the necessary sensitivity and selectivity to be directly applied for quantification in biological samples.

OBJECTIVE

Current research work aimed to develop a rapid, specific, selective, and sensitive method using plasma as one of the biological samples for quantification of Efinaconazole (EZ) in the presence of Fluconazole (FZ) as an internal standard by tandem mass spectrometry (LC-MS/MS).

METHODS

Chromatographic separation was achieved with a Thermo Hypersil Gold (100 mm x 2.1 mm, 1.9 μm) UPLC column using a mobile phase composed of 20% formic acid-water (0.1%) and 80% methanol. Liquid-liquid extraction (LLE) was employed for sample preparation. Efinaconazole and the internal standard were detected using the heated electrospray ionization (HESI) technique in parallel reaction monitoring (PRM) mode.

RESULTS

The developed method displayed a linearity range of 1 to 2000 pg/mL (0.001-2 ng/mL). Precision and accuracy for the lower limit of quantitation, low, mid, and high-quality control (QC) levels demonstrated a variance of less than 5% and an accuracy of 99 to 103%. Long-term stability was confirmed under various conditions, including storage in an auto-sampler, at room temperature, in a deep freezer, and after freeze-thaw cycles.

CONCLUSION

The validated LC-MS/MS method has exceptional sensitivity, specificity, selectivity, rapid analysis, minimal requirement of sample quantity, wide dynamic range of concentration, robustness, and reproducibility, making it an indispensable tool, especially in fields of in vitro Permeation Testing (IVPT), in vitro Release Testing (IVRT), Pharmacokinetic, Toxicology, Clinical studies, and in drug development program for the quantification of Efinaconazole.

Detection of Squalene Epoxidase Mutations in United States Patients with Onychomycosis: Implications for Management

Resistance to oral terbinafine, the most commonly used antifungal to treat dermatophytosis and onychomycosis worldwide, is being increasingly reported. In this study, we aimed to investigate the species distribution and prevalence of squalene epoxidase mutations among toenail dermatophyte isolates. Samples from 15,683 patients suspected of onychomycosis visiting the offices of dermatologists and podiatrists in the United States were analyzed. Clinical information was reviewed, and dermatophyte species with or without squalene epoxidase mutations were detected using multiplex real-time PCRs. The frequency of dermatophytes was 37.6%; of isolates belonging to the Trichophyton genus, 88.3% were the T. rubrum complex, and 11.2% were the T. mentagrophytes complex. Individuals aged >70 years exhibited higher infection rates for the T. mentagrophytes complex. The overall mutation rate among Trichophyton spp. was 3.7%, with a higher mutation rate detected in the T. mentagrophytes complex (4.3 vs. 3.6%). Commonly detected mutations were T1189C/Phe397Leu (34.5%), T1306C/Phe415Ser (16.0%), and C1191A/Phe397Leu (11.0%). Squalene epoxidase gene mutations associated with decreased terbinafine susceptibility have been identified in United States patients with toenail onychomycosis. Physicians should be aware of the risk factors for resistance development and engage in antifungal stewardship practices such as directed diagnosis and treatment of dermatophytosis and onychomycosis.

The accuracy of clinical diagnosis of onychomycosis in Dutch general practice: a diagnostic accuracy study

BACKGROUND

Onychomycosis, the most common cause of nail dystrophy, is generally diagnosed by clinical examination. Current guidelines for Dutch general practice advise confirmatory testing only in cases of doubt or insufficient response to treatment. However, making a correct diagnosis can be challenging given the wide variety of clinical features and differential diagnosis.

AIM

To establish accuracy of clinical diagnosis of onychomycosis by GPs.

DESIGN & SETTING

A diagnostic accuracy study based on GPs' clinical diagnosis of primary care patients suspected of onychomycosis.

METHOD

Using 137 complete datasets from the Onycho Trial, diagnostic accuracy of clinical diagnosis as the index test was compared with confirmatory testing as the reference test. A sensitivity analysis was performed to determine diagnostic values for different combinations of index and reference test. Logistical regression was used to assess which clinical characteristics were associated with the positive predictive value (PPV) of the index test.

RESULTS

Clinical accuracy, that is the PPV of the index test, was 74.5%. Sensitivity analysis showed no significant difference in diagnostic values. Male sex and a history of any previous treatment significantly increased clinical accuracy with an odds ratio (OR) of 3.873 (95% confidence interval [CI] = 1.230 to 12.195, P = 0.021) and OR 4.022 (95% CI = 1.075 to 15.040, P = 0.039), respectively.

CONCLUSION

The study demonstrated that the GPs' clinical diagnosis of onychomycosis was insufficiently accurate to initiate treatment without confirmatory testing. Further research is needed to investigate how to increase clinical accuracy and reduce potentially unnecessary exposure to treatment.

Relative impact of traditional vs. newer oral antifungals for dermatophyte toenail onychomycosis: a network meta-analysis study

BACKGROUND

There is a paucity of evidence regarding the relative therapeutic efficacy of treatments for onychomycosis.

OBJECTIVES

We determined the relative efficacy of monotherapies for dermatophyte toenail onychomycosis with Bayesian network meta-analyses (NMAs).

METHODS

We searched PubMed, Scopus, EMBASE (Ovid) and CINAHL to identify studies that investigated the efficacy of monotherapy with oral antifungals for dermatophyte toenail onychomycosis in adults. In this paper, 'regimen' corresponds to a given agent and its dosage. The relative effects and surface under the cumulative ranking curve (SUCRA) values of the various regimens were estimated; evidence quality was assessed at the study level and across networks.

RESULTS

Data from 21 studies were used. Our two efficacy-related endpoints were: (i) mycological and (ii) complete cure at 1 year; safety--related endpoints were: (i) 1-year count of any adverse event (AE), (ii) 1-year odds of discontinuation due to any AE, (iii) 1-year odds of discontinuation due to liver issues. Thirty-five regimens were identified; the newer agents among these included posaconazole and oteseconazole. We compared the efficacy of newer regimens with traditional ones like 'terbinafine 250 mg daily for 12 weeks' and 'itraconazole 200 mg daily for 12 weeks. We found that an agent's dosage was associated with its efficacy; for example, the 1-year odds of mycological cure with terbinafine 250 mg daily for 24 weeks (SUCRA = 92.4%) were significantly greater than those of terbinafine 250 mg daily for 12 weeks (SUCRA = 66.3%) (odds ratio 2.62, 95% credible interval 1.57-4.54). We also found that booster regimens can increase efficacy. Our results showed that some triazoles could be more effective than terbinafine.

CONCLUSIONS

This is the first NMA study of monotherapeutic antifungals - and their various dosages - for dermatophyte toenail onychomycosis. Our findings could provide guidance for the selection of the most appropriate antifungal agent, especially amid the growing concerns about terbinafine resistance.

Therapeutic treatment strategies for the management of onychomycosis: a patent perspective

INTRODUCTION

Onychomycosis, a multifactorial fungal infection of the nails, shows a global prevalence of about 5.5% and is responsible for 50% of all nail infections. To develop effective management strategies, it is necessary to understand the etiology, pathophysiology, and risk factors of onychomycosis. Oral route of drug delivery is one of the routes utilized to deliver anti-fungal agents, but, has its own limitations like longer duration of treatment, increased adverse effects, and potential for drug interaction. The ungual route has received greater attention due to its localized, non- invasive action and improved patient compliance.

AREAS COVERED

This review comprehensively discusses conventional onychomycosis therapies and patented novel drug delivery systems for the management of onychomycosis including chemical permeation enhancers, non-particulate drug delivery systems, penetration enhancing devices etc., Databases such as PubMed, ResearchGate, and Google Patents were searched by using the keywords onychomycosis and trans-ungual drug delivery.

EXPERT OPINION

Enormous research has been conducted and is still ongoing to find the best possible novel drug delivery system for onychomycosis management. Approaches like incorporation of herbal constituents in nano-formulations, inkjet printing, laser devices, iontophoretic techniques, etc. can be employed to make safe and effective drug delivery systems which are regulatory compliant.

Single-Point Nail Sampling to Diagnose Onychomycosis Caused by Non-Dermatophyte Molds: Utility of Polymerase Chain Reaction (PCR) and Histopathology

The three most commonly used methods for diagnosing non-dermatophyte mold (NDM) onychomycosis are culture, polymerase chain reaction (PCR), and histopathology. Toenail samples from 512 patients (1 sample/patient) with suspected onychomycosis were examined using all three diagnostic tests. A statistically significant association was found between PCR and histopathology results, as well as between fungal culture and histopathology results. All PCR-positive and culture-positive dermatophyte samples were confirmed by histopathology. However, 15/116 (12.9%) of culture-positive NDM samples had negative histopathology results, while all PCR-positive NDM samples were confirmed by histopathology. The overall rate of dermatophyte detection was higher using PCR compared to culture (38.9% vs. 11.7%); the lower rate of NDM detection by PCR (11.7% vs. 38.9%) could be attributed to the restriction of the assay design to seven pre-selected targets. When repeat sampling in the clinic is not possible, a combination of NDM detection by PCR and positive histopathology of hyphae may be a proxy for NDM infection, particularly where the NDM occurs without a concomitant dermatophyte. There was a high degree of correlation between negative PCR and negative histopathology. A negative PCR result with negative histopathology findings may be a reliable proxy for the diagnosis of non-fungal dystrophy.

Cutaneous Fungal Infections Caused by Dermatophytes and Non-Dermatophytes: An Updated Comprehensive Review of Epidemiology, Clinical Presentations, and Diagnostic Testing

Cutaneous fungal infection of the skin and nails poses a significant global public health challenge. Dermatophyte infection, mainly caused by Trichophyton spp., is the primary pathogenic agent responsible for skin, hair, and nail infections worldwide. The epidemiology of these infections varies depending on the geographic location and specific population. However, epidemiological pattern changes have occurred over the past decade. The widespread availability of antimicrobials has led to an increased risk of promoting resistant strains through inappropriate treatment. The escalating prevalence of resistant Trichophyton spp. infections in the past decade has raised serious healthcare concerns on a global scale. Non-dermatophyte infections, on the other hand, present even greater challenges in terms of treatment due to the high failure rate of antifungal therapy. These organisms primarily target the nails, feet, and hands. The diagnosis of cutaneous fungal infections relies on clinical presentation, laboratory investigations, and other ancillary tools available in an outpatient care setting. This review aims to present an updated and comprehensive analysis of the epidemiology, clinical manifestations, and diagnostic testing methods for cutaneous fungal infections caused by dermatophytes and non-dermatophytes. An accurate diagnosis is crucial for effective management and minimizing the risk of antifungal resistance.

Onychomycosis: Old and New

Onychomycosis is a common chronic fungal infection of the nail that causes discoloration and/or thickening of the nail plate. Oral agents are generally preferred, except in the case of mild toenail infection limited to the distal nail plate. Terbinafine and itraconazole are the only approved oral therapies, and fluconazole is commonly utilized off-label. Cure rates with these therapies are limited, and resistance to terbinafine is starting to develop worldwide. In this review, we aim to review current oral treatment options for onychomycosis, as well as novel oral drugs that may have promising results in the treatment of onychomycosis.

Evaluation of Thermography as a Diagnostic Technique in Asymptomatic or Incipient Onychomycosis

Onychomycosis is usually diagnosed symptomatically due to the very clear signs caused by the fungus on the nail surface and structure, although the growth of the infecting agent must also be verified by culture in an enriched medium. This procedure is normally lengthy (four weeks), and samples can be contaminated, delaying the prescription of appropriate and effective treatment. Only one previous study has addressed the possibility of using thermography as a diagnostic method for onychomycosis in older people (31-70 years). The present study confirms this use but in individuals aged 18-31 years with incipient mycosis and no pathological signs. Using an FLIR E60 BX camera in a study with 214 samples, we found that men had more onychomycosis than women. We observed a relation between the presence of infection and nail temperature, with a higher temperature in yeast infections (+1 °C) and a lower temperature in dermatophyte infections (-2 °C). A higher temperature by almost 1 °C was also observed in older participants. Thermography can be viewed as a new diagnostic method in asymptomatic or incipient onychomycosis, providing the thermographic camera is sufficiently sensitive and the appropriate procedure is followed, although fungal culture is always necessary to confirm recovery after treatment.

Fractional CO2 laser - assisted methylene blue photodynamic therapy is a potential alternative therapy for onychomycosis in the era of antifungal resistance

BACKGROUND

Treatment of onychomycosis is challenging by virtue of the impact of nail disfigurement, the location of the fungi within the nail and reported antifungal resistance worldwide. Light-based technologies are promising primary or adjunctive therapeutic modalities. We aimed to compare the efficacy of photodynamic therapy and fractional CO2 laser monotherapy either alone or in combination for onychomycosis.

PATIENTS AND METHODS

This prospective randomized comparative study was conducted on 51 onychomycosis patients divided into three groups. In group A, patients were treated using 6 photodynamic therapy sessions using methylene blue and IPL (560 to 700 nm, fluence 12 J/cm2). Group B patients were treated using 6 bimonthly fractional CO2 laser sessions (10,600 nm, 1.600 mj energy and 0.6 mm density) and group C patients were treated using 6 combined fractional CO2 laser and photodynamic therapy sessions. Patients were evaluated mycologically, dermoscopically and clinically by calculation of proximal nail diameter percentage at baseline, monthly, at the end of treatment and after a 6-month follow-up period post-treatment.

RESULTS

Candida was the most commonly isolated organismin in 64.7%, 70.6% and 70.6% of the pateints in groups A, B and C, respectively. The dermoscopic findings in the total dystrophic onychomycosis was subungual hyperkeratosis in 6 patients (100%), longitudinal streaks and striae in 1 patient (16.7%). In dorsolateral subungual onychomycosis, jagged proximal edge in 31 patients (70.5%), and pigmentation in 30 patients (68.2%) were noted. In proximal subungual onychomycosis irregular matt patches were seen in 1 patient (100%). Proximal nail diameter percentage showed statistically significant improvement after treatment and 6 months follow up in the 3 studied groups. Mean increase of proximal nail diameter after treatment was highest in group C (52.94 ± 20.24), followed by group B (43.82 ± 21.03) and least in group A (35.29 ± 17.0). This difference was statistically significant (p = 0.044). Reported side effects were mild-moderate pain, discoloration and paronychia.

CONCLUSION

We conclude that fractional CO2 laser and photodynamic monotherapy, and their combination achieve high success rates, good patient satisfaction and safety profile. Fractional CO2-assisted photodynamic therapy is associated with the highest improvement over either fractional CO2 or photodynamic therapy alone.

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.

Effect of Topical Antifungal Luliconazole on Hyphal Morphology of Trichophyton mentagrophytes Grown on in vitro Onychomycosis Model

Luliconazole, recently launched in Japan, is a novel topical imidazole antifungal agent for the treatment of onychomycosis. Using in vitro onychomycosis model, the effect of luliconazole on the morphology of the growing hyphae of Trichophyton mentagrophytes was investigated by scanning electron microscopy (SEM). The model was produced by placing human nail pieces on an agar medium seeded with conidia of T. mentagrophytes. After incubating the agar medium for 3 days, luliconazole was applied to the surface of the nail in which hyphal growth was recognized, then cultured for up to 24 h. The initial change after treatment with the drug was the formation of fine wrinkles on the surface of the hyphae, eventually, the hyphae were flattened, and after that, no hyphal growth was observed. On the other hand, when the nails were pretreated with luliconazole for 1 h, no hyphal growth was observed even after culturing for 24 h. This study suggests that luliconazole has a strong antifungal activity by inhibiting the ability of fungi to grow and the drug has both excellent nail permeation and retention properties.

Epidemiology of Onychomycosis in Chinese Mainland: A 30-year Retrospective Study

BACKGROUND

Onychomycosis was a common nail disease caused by dermatophytes, yeasts or molds. The prevalence of onychomycosis varied in different counties and it was necessary to understand the epidemiology in China.

OBJECTIVES

This study was conducted to investigate the epidemiology of onychomycosis in Chinese mainland in the past 30 years.

METHODS

A 30-year systemic review was carried out by searching publications investigating the prevalence of onychomycosis in Chinese mainland from 1991 to 2020.

RESULTS

A total of 90 articles involving more than 40,000 onychomycosis patients were enrolled in this study. The ratio of males to females was 1:1.32. Fingernail onychomycosis was found in 36.12% cases, toenail onychomycosis in 48.31%, and both fingernail and toenail onychomycosis in 15.57%. The most common clinical type of onychomycosis was distal lateral subungual onychomycosis (60.99%), followed by total dystrophic onychomycosis (18.91%), proximal subungual onychomycosis (10.19%) and superficial white onychomycosis (9.92%). Dermatophytes (60.59%) were the most frequently isolated pathogens, followed by yeasts (30.09%), molds (7.91%) and mixed infection (1.41%). The primary pathogens in dermatophytes, yeasts and molds were Trichophyton rubrum (49.93%), Candida albicans (10.99%) and Aspergillus (3.11%), respectively. Additionally, dermatophytes were more commonly affected males than females (63.69% vs. 51.57%), and mostly involved in toenail onychomycosis (75.63%). The infection of yeasts was higher in females than males (40.97% vs. 29.52%), often causing onychomycosis in fingernail than toenail (41.03% vs. 17.08%), and it was more common in warm and humid southern regions than northern area (34.07% vs. 24.41%).

CONCLUSION

The proportion of the causative agents changed over time, dermatophytes, especially T. rubrum had always been the predominant pathogen, followed by yeasts and molds. The distribution of fungal pathogens varied among clinical types, gender, infection sites and geography gender.

Luliconazole Nail Lacquer for the Treatment of Onychomycosis: Formulation, Characterization and In Vitro and Ex Vivo Evaluation

Onychomycosis is the most common fungal infection of the nail affecting the skin under the fingertips and the toes. Currently, available therapy for onychomycosis includes oral and topical therapies, either alone or in combination. Oral antifungal medication has been associated with poor drug bioavailability and potential gastrointestinal and systemic side effects. The objective of this study was to prepare and evaluate the luliconazole nail lacquer (LCZ-NL) for the effective treatment of onychomycosis. In the current work, LCZ-NL was formulated in combination with penetration enhancers to overcome poor penetration. A 3² full factorial formulation design of experiment (DOE) was applied for optimization of batches with consideration of dependent (drying time, viscosity, and rate of drug diffusion) and independent (solvent ratio and film former ratio) variables. The optimized formulation was selected based on drying time, viscosity, and rate of drug diffusion. The optimized formulation was further evaluated for % non-volatile content assay, smoothness of flow, water resistance, drug content, scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), in vitro drug release, ex vivo transungual permeation, antifungal efficacy, and stability study. The optimized LCZ-NL contained 70:30 solvent ratio and 1:1 film former ratio and was found to have ~ 1.79-fold higher rate of drug diffusion in comparison with LULY™. DSC and XRD studies confirmed that luliconazole retains its crystalline property in the prepared formulation. Antifungal study against Trichophyton spp. showed that LCZ-NL has comparatively higher growth inhibition than LULY™. Hence, developed LCZ-NL can be a promising topical drug delivery system for treating onychomycosis.

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.

Antifungal activity of dexamethasone against fluconazole-resistant Candida albicans and its activity against biofilms

Objective: The present study investigated the antifungal action of dexamethasone disodium phosphate (Dex). Methodology: Susceptibility testing was performed using the Clinical & Laboratory Standards Institute protocol; M27-A3, checkerboard test and biofilm were evaluated with two isolates of Candida albicans, hyphal production test, molecular docking analysis and flow cytometry analysis. Result: Dex and fluconazole (FLC) together had a synergistic effect. Mature biofilm was reduced when treated with Dex alone or in combination. Dex and FLC promoted a decrease in the production of hyphae and changes in the level of mitochondrial depolarization, increased generation of reactive oxygen species, loss of membrane integrity, increased phosphatidylserine externalization and molecular docking; there was interaction with ALS3 and SAP5 targets. Conclusion: Dex showed antifungal activity against FLC-resistant C. albicans strains.

Onychomycosis Caused by Fusarium Species

Onychomycosis is a nail fungal infection that produces nail discolouration, thickness, and separation from the nail bed. The species of the Fusarium genus that cause onychomycosis are emerging and the number of cases has increased throughout the years. Microscopic examination, as well as cultures, are required for the accurate diagnosis of onychomycosis. The goal of treatment is to eliminate the organism that causes the disease and restore the nail’s normal appearance. Here, we provide an overview of the onychomycosis cases that have been reported in literature over the last 24 years, which have been caused by the Fusarium species. We performed a review on the onychomycosis cases caused by the Fusarium species from January 1997 to January 2021. Patients aged between 40 and 49 years made up 30.23% of the cases. The most common aetiologic species was Fusarium solani species complex (FSSC), which accounted for 44.11% of the cases, followed by F. fujikuroi species complex (FFSC), which accounted for 17.64%; 14.70% of the cases were due to F. dimerum species complex (FDSC) and 14.70% of the cases were due F. oxysporum species complex (FOSC). Europe accounted for 29.06% of the cases caused by FOSC, whereas Africa accounted for 46.67% of the cases due to FSSC. The clinical presentation of onychomycosis due to Fusarium spp. is commonly the distal–lateral pattern of onychomycosis. Identification of the infectious agent in onychomycosis cases due to Fusarium is crucial in deciding the proper treatment. Although antifungal susceptibility tests have only been performed in a few cases, susceptibility testing can help with patient management.

Correlation of clinical characteristics, by calculation of SCIO index, with the laboratory diagnosis of onychomycosis

INTRODUCTION

Onychomycosis is a chronic fungal infection with increasing incidence and the global prevalence is estimated to be 5.5%. The aim of our study was to perceive objectively severity of onychomycosis by calculating Scoring Clinical Index for Onychomycosis and to correlate this index with accurate laboratory diagnosis in our patients.

MATERIALS AND METHODS

The study population comprised of 417 patients with laboratory confirmed onychomycosis. For each patient, we recorded basic demographic information, site of infection, the most affected nail with onychomycosis, clinical presentation, and type of onychomycosis. The evaluation of the disease severity was based on Scoring Clinical Index for Onychomycosis which was calculated for every patient separately. Mycological identification was done by microscopy and fungal culture.

RESULTS

The majority of patients had distal and lateral subungual onychomycosis (95.44%) that was localized on big toe (62.59%), with female to male ratio 1.24:1. Male patients had significantly more nails affected with onychomycosis compared with female patients (p = 0.011), while female had significantly more often onychomycosis on fingernails 2-5 (p < 0.05), and they reported significantly more often pain (p < 0.05) and esthetic problems (p < 0.05). Mean Scoring Clinical Index for Onychomycosis was 16.76. Dermatophytes were most frequently isolated (91.85%). In patients with onychomycosis caused by dermatophytes, Scoring Clinical Index for Onychomycosis had significantly higher values (p = 0.032).

CONCLUSION

Comprehensive understanding of disease characteristics will allow introduction of individualized treatment plan for each patient, based on proper fungal identification and standardized method of evaluating disease severity, which could help the patient achieve a complete cure.

A drug-in-adhesive anti-onychomycotic nail patch: Influence of drug and adhesive nature on drug release, ungual permeation, in vivo residence in human and anti-fungal efficacy

A nail patch is an attractive option for the topical treatment of onychomycosis, although no product is commercially available. We previously identified optimal nail patch formulations for two anti-onychomycotic drugs, based on their properties, as well as those of the other patch components. In this paper, our aim was to further investigate the potential of the patch formulations as topical nail medicines, in particular, whether the drug-in-adhesive patches release drug which then permeates into and through the nail plate and show anti-fungal efficacy, and whether and to what extent they remain adhered to the human nail plate in vivo when tested over 2 week durations. In addition, the influence of the drug (amorolfine HCl, ciclopirox olamine) and PSA (Duro-Tak 2852 or Duro-Tak 202A) on these parameters was determined. We found that both the nature of the drug and of the PSA influenced in vitro drug release. The nature of the drug, but not that of the PSA, influenced ungual drug permeation through human nail clippings, with considerably greater (almost double) permeation for ciclopirox olamine, the smaller and less lipophilic molecule. In vivo residence, tested with 3 out of the 4 patches, excluding the patch where ciclopirox olamine degraded with time, showed greater residence on toenails compared to fingernails reflecting their far lesser exposure to environmental stresses during daily activities. In vivo residence was enhanced when the patch was cut to the shape of the nail, was applied at bedtime, and when a clear colourless nail varnish was applied on top of the patch to 'seal' it into place on the nail. Comparison of the patches indicated greater residence of Duro-Tak 202A containing patches over those containing Duro-Tak 2852. Amorolfine HCl in Duro-Tak 202A based patch also showed antifungal efficacy in contrast to Duro-Tak 2852-based patch, and is particularly promising for further development as a potential toenail medicine, remaining almost fully adhered to toenails for at least two weeks.

Transmission of Onychomycosis and Dermatophytosis between Household Members: A Scoping Review

Onychomycosis is a common fungal infection of the nail, caused by dermatophytes, non-dermatophytes, and yeasts. Predisposing factors include older age, trauma, diabetes, immunosuppression, and previous history of nail psoriasis or tinea pedis. Though many biological risk factors have been well characterized, the role of the environment has been less clear. Studies have found evidence of transmission in 44% to 47% of households with at least one affected individual, but the underlying mechanisms and risk factors for transmission of onychomycosis between household members are incompletely understood. A scoping literature review was performed to characterize and summarize environmental risk factors involved in the transmission of onychomycosis within households. A total of 90 papers met the inclusion criteria, and extracted data was analyzed in an iterative manner. Shared household surfaces may harbor dermatophytes and provide sources for infection. Shared household equipment, including footwear, bedding, and nail tools, may transmit dermatophytes. The persistence of dermatophytes on household cleaning supplies, linen, and pets may serve as lasting sources of infection. Based on these findings, we provide recommendations that aim to interrupt household transmission of onychomycosis. Further investigation of the specific mechanisms behind household spread is needed to break the cycle of transmission, reducing the physical and social impacts of onychomycosis.

Review of the alternative therapies for onychomycosis and superficial fungal infections: posaconazole, fosravuconazole, voriconazole, oteseconazole

Terbinafine and itraconazole are the most commonly used oral antifungals to treat onychomycosis and superficial dermatomycoses. Recently, poor response to oral terbinafine has been reported. We have summarized the most appropriate dosing regimens of posaconazole, fosravuconazole, voriconazole, and oteseconazole (VT-1161) to treat onychomycosis and superficial fungal infections. A structured search on PubMed and Google Scholar was conducted. Additionally, the bibliographies of selected articles were searched to identify relevant records. The number of records identified from the searches was 463, with 50 articles meeting the inclusion criteria for review. None of the new azoles are US FDA approved for onychomycosis treatment; however, an increasing number of studies have evaluated these agents. The efficacies (complete cure and mycologic cure) of the antifungal agents for dermatophyte great toenail onychomycosis treatment are terbinafine 250 mg/day × 12 weeks (Phase III trial) (38%, 70%), itraconazole 200 mg/day × 12 weeks (Phase III trial) (14%, 54%), posaconazole 200 mg/day × 24 weeks (Phase IIB) (54.1%, 70.3%), fosravuconazole 100 mg/day ravuconazole equivalent × 12 weeks (Phase III) (59.4%, 82.0%), and oteseconazole 300 mg/day loading dose × 2 weeks (Phase II), followed by 300 mg/week × 10 weeks (maintenance dose) (45%, 70%). Guidelines for monitoring are also presented.

Biofilms and the Nail Unit

Recent studies have shown that a superficial fungal infection such as onychomycosis may form complex biofilms. Although most individuals susceptible to documented fungal biofilm infections are immunocompromised, physical damage to the nail or concurrent infection with other organisms is also a common risk factor in developing nail biofilm. The complex nature of the biofilm, which includes efflux pumps and the formation of a virulent extracellular matrix, helps it evade the immune system. Although there is no standardized treatment for fungal biofilms in onychomycosis, various studies using antimicrobials and lasers have shown some efficacy in treating human fingernails.

A comparative study between two antifungal agents, Luliconazole and Efinaconazole, of their preventive effects in a Trichophyton-infected guinea pig onychomycosis model

An efficacious period of two topical antifungal drugs was compared in a Trichophyton mentagrophytes-infected onychomycosis model in guinea pigs treated with antifungal drugs prior to infection. Luliconazole 5% (LLCZ) and efinaconazole 10% (EFCZ) test solutions were applied to the animals’ nails once daily for 2 weeks followed by a nontreatment period of 2, 4, and 8 weeks. After each nontreatment period, the nails were artificially infected by the fungus. Drug efficacy was quantitatively evaluated by qPCR and histopathological examination of the nails collected following a 4-week post-infection period. The fungal infection was confirmed in the untreated group. Both LLCZ and EFCZ prevented fungal infection in the treated groups with the nontreatment period of 2 weeks. After the nontreatment period of 4 weeks, no infection was observed in the LLCZ-treated group; however, infection into the nail surface and fungal invasion into the nail bed were observed in the EFCZ-treated group. After the nontreatment period of 8 weeks, fungi were found in the nail surface and nail bed in some nails treated with EFCZ; however, no infection was observed in the nail bed of the LLCZ-treated group. The results suggest that LLCZ possesses longer-lasting antifungal effect in nails of the guinea pigs than EFCZ, and that this animal model could be useful for translational research between preclinical and clinical studies to evaluate the pharmacological efficacy of antifungal drugs to treat onychomycosis. This experimentally shown longer-lasting preventive effects of LLCZ could also decrease the likelihoods of onychomycosis recurrence clinically.

Epidemiological analysis of nail aspergillosis and non-dermatophyte moulds. Criteria for the involvement of Aspergillus in 102 cases of onychomycosis at Montpellier University Hospital, France (1991-2019)

BACKGROUND

Moulds are often wrongly considered contaminants, not very sensitive to conventional antifungal treatments, but they may cause ungual hyphomycosis, particularly Aspergillus. Due to the lack of precise diagnostic criteria, their real impact is underestimated.

OBJECTIVES

Retrospective descriptive analysis of all ungual hyphomycosis cases diagnosed at Montpellier Hospital from 1991 to 2019 to: (i) determine the incidence of onychomycosis by pseudo-dermatophytes and moulds; (ii) perform an epidemiological analysis of nail aspergillosis; and (iii) provide simple criteria for mould involvement in onychopathy.

PATIENTS/METHODS

Data concerning 4053 patients were collected: age, sex, onychomycosis location, direct examination results, species(s) identified and fungal co-infections. Moreover, clinical data of patients with nail aspergillosis were analysed to identify potential contributing factors, and the classical criteria for mould involvement in onychopathy were critically reviewed.

RESULTS

A pseudo-dermatophyte or a mould was involved in nail colonisation in 17.25% of patients (men/women ratio: 0.70; mean age: 53.1 years). The identified hyphomycetes belonged mainly to the genera Fusarium (45.68%), Scopulariopsis (30.23%) and Aspergillus (16.94%). Analysis of the clinical reports of 102 patients with ungual aspergillosis (men/women ratio: 0.67; mean age: 56.3 years) identified cardiovascular (43.9%), endocrine (25.8%), cancer (19.7%) and skin (18.2%) diseases as contributing factors.

CONCLUSIONS

The adoption of simple and reliable criteria (ie, characteristic filaments on direct microscopic examination after periodic acid-Schiff staining, growth at seeding points in culture) allows determining the formal involvement of a mould in chronic onychopathies and avoiding possible side effects and costs of empirical or inappropriate and repetitive treatments.

A Mycological and Molecular Epidemiologic Study on Onychomycosis and Determination In Vitro Susceptibilities of Isolated Fungal Strains to Conventional and New Antifungals

Background

Onychomycosis is one of the most common and recurrent dermatological diseases worldwide. The antimycotic activity of prescribed medications varies according to the causative agents, and treatment failure rates exceeding 30%. This study aimed to assess the epidemiological profile of onychomycosis in Iran. Also, the susceptibilities to conventional and new antifungals were investigated.

Methods

In this descriptive cross-sectional study, during the period of 18 months starting from September 2019 until March 2020, 594 nail specimens were obtained from patients who presented nail changes compatible with a clinical diagnosis of onychomycosis. The patients were referred from different cities, including Tehran, Kermanshah, Arak, Kashan, Rasht, Qom, Urmia, Zahedan, Hamadan, Zanjan, Borujerd, Bushehr, and Yazd. All the samples were subjected to microscopic examination and fungal culture. Fungi identified were confirmed through the PCR-sequencing method. The susceptibility to itraconazole, fluconazole, terbinafine, griseofulvin, posaconazole, ravuconazole, efinaconazole, luliconazole, and tavaborole was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) guidelines, document M38-A2 for filamentous fungi, and document M27-A3 for yeasts.

Results

594 patients were included. Of these, in 179 cases (30.1%) (95% CI:0.3 ± 0.037) onychomycosis was confirmed. The majority of patients were ≥ 60 years of age (n=58, 32.6%) and female (n=113, 63.1%). Saprophytic fungi accounted for the vast majority of the nail isolates (n=92, 51.4%) (95% CI:0.051 ± 0.0.073), followed by dermatophytes (n=45, 25.1%) (95% CI:0.25 ± 0.063), and yeasts (n=42, 23.5%) (95% CI:0.23 ± 0.061). Diabetes mellitus (77.3%), hypothyroidism (18.2%), and solid tumors (4.5%) were documented as the most prevalent underlying conditions. Antifungal susceptibility testing was performed against 60 fungal isolates (20 each of Candida species, saprophytic fungi, and dermatophytes). Efinaconazole, ravuconazole, and luliconazole were the most active agents against Candida species. Also, luliconazole, posaconazole, and efinaconazole were most potent against dermatophytes. Luliconazole had the greatest antifungal activity against saprophytic fungi.

Conclusions

The prevalence of onychomycosis in Iranian patients was relatively high. LUL exhibited potent antifungal activity against the three groups of fungi tested, determining its broad-spectrum antimycotic activity and its probable use as the first-line therapy for onychomycosis.

Laboratory monitoring during treatment of onychomycosis in pediatric patients: A survey of provider perspectives and practices

BACKGROUND/OBJECTIVES

Literature regarding the cost and necessity of laboratory monitoring during oral antifungal treatment in adults has recently been published. However, consensus guidelines for the treatment and monitoring of pediatric patients with systemic antifungals for onychomycosis are lacking. We sought to evaluate both the practice trends and perspectives of pediatric dermatology providers who treat pediatric onychomycosis.

METHODS

An electronic survey was administered to providers belonging to the Society for Pediatric Dermatology (SPD) and/or Pediatric Dermatology Research Alliance (PeDRA) regarding their clinical practice and reasoning for laboratory monitoring during the treatment of pediatric onychomycosis.

RESULTS

One hundred and twenty-one providers completed the survey (12.5%). 77% identified themselves as pediatric dermatologists. A majority practice in the academic setting (51%), and 54% were primarily only pediatric providers. All respondents prescribe oral terbinafine for onychomycosis. 88% of respondents always or almost always confirm the diagnosis of onychomycosis prior to prescribing oral terbinafine for onychomycosis. 39% always or almost always routinely order baseline laboratory tests while 40% never or almost never do. 41% never or almost never order monitoring laboratory tests during treatment while 32% always or almost always do. 91.5% have never discovered a significant reaction to terbinafine with routine monitoring.

CONCLUSION

Pediatric dermatology providers are very likely to confirm the diagnosis of onychomycosis prior to systemic treatment. Significant variability was found in pretreatment and treatment laboratory monitoring, reasons for laboratory monitoring or deferral of testing, and timing of testing among providers. Knowledge of current practice trends as well as provider perspectives may be useful in the future development of consensus guidelines.

Lasiodiplodia theobromae onychomycosis among agricultural workers: A case series

Lasiodiplodia theobromae is a dematiaceous non-dermatophyte mold (NDM), rarely reported to cause onychomycosis. Here, we report three cases of toenail onychomycosis caused by L. theobromae in agricultural workers. Two patients presented with total dystrophic onychomycosis and one with distal and lateral subungual onychomycosis. These cases have unique importance that besides traumatized nail infection, its rarity has adversely affected the agricultural workers livelihood as L. theobromae sporulates poorly, resistant to commonly used antifungal therapy. From the literature search, we assume that this is the first case series of onychomycosis caused by L. theobromae from a tropical country like India.

Cure Rates of Control Interventions in Randomized Trials for Onychomycosis Treatments: A Systematic Review and Meta-Analysis

Background: The efficacy of antifungals for onychomycosis has been determined in randomized controlled trials (RCTs); interestingly their control arms have demonstrated some therapeutic effects. These controls constitute either placebos (inert pills) or vehicles (all but the antifungal component of the creams). The objective of this research was to determine (i) whether RCT controls exhibited statistically-relevant efficacy rates (i.e. beyond the "placebo effect"), (ii) whether oral and topical controls differed in their efficacies, and (iii) if the efficacy rates of the controls correlated with those of the active comparator associated with that control.

Methods: RCTs of oral and topical monotherapies for dermatophyte toenail onychomycosis were identified through a systematic literature search. For our meta-analyses of cure rates the double arcsine transformation was used. The N-1 chi squared test was used to determine whether the cure rates significantly differed between topical and oral controls. Correlation was investigated using Kendall rank correlation tests.

Results: The pooled mycological, complete, and clinical cure rates of all control interventions (n = 19 trials) were 9%, 1%, and 6%, respectively. The pooled efficacy rates for oral and topical controls were: mycological cure rate, 7% and 12% (p=0.0016); complete cure rate, 1% for both; and clinical cure rate, 4% and 8%, respectively (p=0.0033). For oral RCTs, the respective cure rates of the active therapies were not correlated with controls. However, for topical RCTs, as the mycological and clinical cure rates of the active therapy increased, so did those of the topical vehicle associated with the active therapy in question, and vice versa.

Conclusions: The topical vehicle cure rates were often higher than the oral placebo cure rates, likely due to the presence of non-antifungal chemicals (e.g. moisturizers, urea) with antifungal and debriding properties, which are not present in oral controls.

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Translation and Cross-Cultural Adaptation of Quality of Life Scale in Patients with Onychomycosis

(1) Background: Onychomycosis (OM) is a fungal nail infection, considered a risk factor for diabetic foot ulcers. It is associated with changes in quality of life, in terms of pain, self-confidence and self-esteem. The aim was to translate and adapt the OM quality of life questionnaire "OnyCOE-t^TM-Quality Of Life Questionnaire Onychomycosis (Nail Fungal Condition)". (2) Methods: This study followed the guidelines proposed by Beaton et al. (2000), where two English to Portuguese translations were performed and, after an expert consensus, a common version was obtained. This was followed by two back-translations. The expert committee achieved semantic equivalence, idioms and concepts. The pre-test was applied to 49 people. The final version and processed data were sent to the authors. (3) Results: We adapted terms semantically, modified statements syntactically, altering items from interrogative to affirmative. (4) Conclusions: The translated version of the "Quality of life-Onychomycosis" questionnaire suggested that it can be used for further studies to test validity and reliability in this population.

Molecular Epidemiology and Antifungal Susceptibility of Trichophyton Isolates in Greece: Emergence of Terbinafine-Resistant Trichophytonmentagrophytes Type VIII Locally and Globally

Trichophyton isolates with reduced susceptibility to antifungals are now increasingly reported worldwide. We therefore studied the molecular epidemiology and the in vitro antifungal susceptibility patterns of Greek Trichophyton isolates over the last 10 years with the newly released EUCAST reference method for dermatophytes. Literature was reviewed to assess the global burden of antifungal resistance in Trichophyton spp. The in vitro susceptibility of 112 Trichophyton spp. molecularly identified clinical isolates (70 T. rubrum, 24 T. mentagrophytes, 12 T. interdigitale and 6 T. tonsurans) was tested against terbinafine, itraconazole, voriconazole and amorolfine (EUCAST E.DEF 11.0). Isolates were genotyped based on the internal transcribed spacer (ITS) sequences and the target gene squalene epoxidase (SQLE) was sequenced for isolates with reduced susceptibility to terbinafine. All T. rubrum, T. interdigitale and T. tonsurans isolates were classified as wild-type (WT) to all antifungals, whereas 9/24 (37.5%) T. mentagrophytes strains displayed elevated terbinafine MICs (0.25–8 mg/L) but not to azoles and amorolfine. All T. interdigitale isolates belonged to ITS Type II, while T. mentagrophytes isolates belonged to ITS Type III* (n = 11), VIII (n = 9) and VII (n = 4). All non-WT T. mentagrophytes isolates belonged to Indian Genotype VIII and harbored Leu393Ser (n = 5) and Phe397Leu (n = 4) SQLE mutations. Terbinafine resistance rates ranged globally from 0–44% for T. rubrum and 0–76% for T. interdigitale/T. mentagrophytes with strong endemicity. High incidence (37.5%) of terbinafine non-WT T. mentagrophytes isolates (all belonging to ITS Type VIII) without cross-resistance to other antifungals was found for the first time in Greece. This finding must alarm for susceptibility testing of dermatophytes at a local scale particularly in non-responding dermatophytoses.

Dermatophyte infections in children compared to adults in Germany: a retrospective multicenter study in Germany

BACKGROUND AND OBJECTIVE

Dermatophyte infections of the skin and nails are common worldwide and vary between geographical areas and over time. The aim of this study was to determine the epidemiological profile of dermatophytes in Germany with a focus on comparing children with adults.

PATIENTS AND METHODS

In this retrospective multicenter study, mycological dermatophyte culture results in the period 01/2014 to 12/2016 were analyzed according to identified pathogen, age and gender of patients, and type of disease.

RESULTS

Of 1,136 infections (children: n = 88, adults: n = 1,048), 50.8 % were clinically classified as onychomycosis, followed by tinea pedis (34.6 %), tinea corporis (16.2 %), tinea manus (16.2 %), tinea capitis (2.5 %), and tinea faciei (1.2 %). The most frequent pathogen was Trichophyton (T.) rubrum (78.6 %), followed by T. interdigitale (14.3 %), T. benhamiae (3.2 %), T. mentagrophytes (2.1 %), and Microsporum canis (1.7 %). The fungal spectrum differed particularly in tinea corporis and tinea capitis between children and adults with a more diverse pathogen spectrum in children. Trichophyton tonsurans was rarely identified as cause for tinea corporis (2.7 %) or tinea capitis (3.3 %).

CONCLUSIONS

Differences in pathogens and frequency of fungal infections between age groups should be considered for optimal selection of the appropriate therapeutic regimen.

Epidemiology of Dermatophytes in Belgium: A 5 Years' Survey

Dermatophytes are among the most common fungal agents causing superficial skin infections worldwide. Epidemiology of these infections is evolving and variable in every country. This report presents the Belgian epidemiological data regarding the distribution of dermatophytes species isolated by the two national reference centers for mycosis during a period of 5 years (2012-2016). Trichophyton rubrum was the most frequently isolated species, considering all sampling sites (60.3% on average between 2012 and 2016). More precisely, this dermatophyte was the major agent of Tinea unguium and Tinea corporis during this period, followed by species of the Trichophyton mentagrophytes complex. Moreover, Microsporum audouinii was the main etiological agent of Tinea capitis (TC) with a frequency of 52.5% on average between 2012 and 2016. Other African dermatophytes species such as Trichophyton soudanense and Trichophyton violaceum were also agents of TC with a respective prevalence of 11.6% and 11.5% on average. This study highlights a different dermatophyte distribution in Belgium in comparison with other European countries.

Diagnosis of Onychomycosis: From Conventional Techniques and Dermoscopy to Artificial Intelligence

Onychomycosis is a common fungal nail infection. Accurate diagnosis is critical as onychomycosis is transmissible between humans and impacts patients' quality of life. Combining clinical examination with mycological testing ensures accurate diagnosis. Conventional diagnostic techniques, including potassium hydroxide testing, fungal culture and histopathology of nail clippings, detect fungal species within nails. New diagnostic tools have been developed recently which either improve detection of onychomycosis clinically, including dermoscopy, reflectance confocal microscopy and artificial intelligence, or mycologically, such as molecular assays. Dermoscopy is cost-effective and non-invasive, allowing clinicians to discern microscopic features of onychomycosis and fungal melanonychia. Reflectance confocal microscopy enables clinicians to observe bright filamentous septate hyphae at near histologic resolution by the bedside. Artificial intelligence may prompt patients to seek further assessment for nails that are suspicious for onychomycosis. This review evaluates the current landscape of diagnostic techniques for onychomycosis.