Update on current approaches to diagnosis and treatment of onychomycosis

Development of microemulgel formulations with varied permeation enhancers for transungual delivery of luliconazole in onychomycosis management

Luliconazole-loaded microemulgels containing different permeation enhancers were formulated for transungual drug delivery for the management of onychomycosis, onychomycosis, which affects nails. The physicochemical properties like droplet size, zeta potential, pH, viscosity, spreadability, extrudability, oil binding capacity, drug content, and microscopic study were evaluated. The Pseudo-ternary phase diagram was constructed for the formulation of microemulsions (MEs) by keeping the Km ratio constant at 3:1 and characterized for clarity, mean droplet size, zeta potential, viscosity, pH, transmittance, refractive index, and stability. The ME mean droplet size and zeta potential were found in the range of 38.78 to 171.4 nm, and 0.00 to - 6.6 mV, respectively. Prepared MEs were converted into microemulgel by adding a 2.5% gelling agent (Carbapol 934) in the external phase, and a drug release study was conducted. Formulation E3 showed better drug release and was chosen as the control. Four different penetration enhancers were added separately within E3 and further evaluated for pH, viscosity, spreadability, extrudability, oil binding capacity, drug content, microscopic study, Compatibility study, XRD, and DSC. A favorable docking score was observed between luliconazole and Lanosterol 14-alpha-demethylase. In-vitro cumulative drug release at the end of 24 h from E3-SS, containing sodium sulfide as a penetration enhancer, was found to be 94.70% and was 2 times more than the control formulation. Ex-vivo transungual permeation studies through cutting nail clippings were found to be in the range of 28.18 - 36.52 µg/mm2. The microemulgels tagged as E3, E3-SS, and E3-SL showed a significant zone of inhibition against Candida albicans and Aspergillus fumigatus as compared to the marketed formulation.

Novel Discoveries and Clinical Advancements for Treating Onychomycosis: A Mechanistic Insight

Onychomycosis continues to be the most challenging disease condition for pharmaceutical scientists to develop an effective drug delivery system. Treatment challenges lie in incomplete cure and high relapse rate. Present compilation provides cumulative information on pathophysiology, diagnostic techniques, and conventional treatment strategies to manage onychomycosis. Novel technologies developed for successful delivery of antifungal molecules are also discussed in brief. Multidirectional information offered by this article also unlocks the panoramic view of leading patented technologies and clinical trials. The obtained clinical landscape recommends the use of advanced technology driven approaches, as a promising way-out for treatment of onychomycosis. Collectively, present review warrants the application of novel technologies for the successful management of onychomycosis. This review will assist readers to envision a better understanding about the technologies available for combating onychomycosis. We also trust that these contributions address and certainly will encourage the design and development of nanocarriers-based delivery vehicles for effective management of onychomycosis.

Onychomycosis due to Fusarium species in different continents, literature review on diagnosis and treatment

Fusarium species are an emerging cause of onychomycosis, and the number of cases has dramatically increased in recent decades worldwide. This review presents an overview of the onychomycosis cases caused by Fusarium species and diagnosis and treatment that have been reported in the literature. The most common causative agent of onychomycosis is F. solani species complex, which accounts for 11.68% of the cases of Fusarium onychomycosis, followed by the F. oxysporum species complex (164 out of 1669), which is accounted for 9.83% of the total. F. fujikuroi species complex (42 out of 1669) and F. dimerum species complex (7 out of 1669) are responsible for 2.52% and 0.42 cases, respectively. Fusarium nail infections were reported in patients aged range 1-98, accounting for 5.55% (1669 out of 30082) of all cases. Asia has the highest species diversity of Fusarium onychomycosis (31.51%). South America accounts for 21.09%, and the most common causative agent is F. solani (19.32%), followed by F. oxysporum species complex (15.63%). Europe accounts for 4.90% of cases caused by F. oxysporum, followed by F. solani. Africa accounts for 23.87% of the cases due to the F. solani species complex, followed by F. oxysporum and F. fujikuroi. Distal and lateral subungual onychomycosis was the most common clinical symptom accounting for 58.7% (135 out of 230) of the cases. Data analysis relieved that terbinafine and itraconazole are active treatments for Fusarium onychomycosis. For a definitive diagnosis, combining of direct examination, culture and sequencing of the elongation factor of translation 1α are recommended. Accurate identification of the causative agents of onychomycosis due to Fusarium species and antifungal susceptibility testing is essential in patient management.

Development and Validation of a Patient-Reported Outcome Measure for Fingernail and Toenail Conditions: The NAIL-Q

Background

Patient-reported outcome measures (PROMs) are needed to measure outcomes that matter to people with nail conditions, from their perspective.

Objective

To design a comprehensive new PROM (NAIL-Q) to measure outcomes important in toenail and fingernail conditions.

Methods

A mixed methods iterative approach was used. Phase 1 involved concept elicitation interviews that were audio-recorded, transcribed, and coded line-by-line. Concepts were developed into scales and refined through cognitive debriefing interviews with patients and expert input. Data was then collected from an international sample using a crowdsource platform. Eligible participants were aged ≥18 years with a nail condition for at least 3 months. Rasch Measurement Theory (RMT) analysis was used to examine item and scale performance. Other psychometric tests included test-retest reliability, and convergent and construct validity.

Results

Phase 1 interviews involved 23 patients with 10 nail conditions and input from 11 dermatologists. The analysis led to the development of 84 items for field-testing. In Phase 2, 555 participants completed the survey. Toenail conditions (n = 441) were more common than fingernail conditions (n = 186). The RMT analysis reduced the number of items tested to 45 in 7 scales measuring nail appearance, health-related quality of life concerns, and treatment outcomes. All items had ordered thresholds and nonsignificant chi-square p values. Reliability statistics with and without extremes for the Person Separation Index were ≥0.79 and Cronbach's alpha were ≥0.83, and for intraclass correlation coefficients were ≥0.81. Construct validity was further supported in that most participants agreed that the NAIL-Q was easy to understand, asked relevant and important questions in a respectful way, and that it should be used to inform clinical care.

Conclusion

The NAIL-Q is a rigorously designed and tested PROM that measures nail appearance, health-related quality of life and treatment outcomes. This PROM can be used in clinical practice to inform patient care and to include the patient perspective in research.

Comparative analysis of onychomycosis in Puerto Rico using molecular and conventional approaches

Onychomycosis is the most prevalent nail ailment in adults, accounting for 50% of all nail infections. Dermatophyte fungi are the primary cause, but non-dermatophyte molds (NDM) and yeasts can also cause onychomycosis. It remains important to precisely determine the fungal cause of onychomycosis since the response to current treatments may vary between fungal classes. Real-time polymerase chain reaction (qPCR) has become a widespread tool for detecting fungal organisms for diagnosis due to its sensitivity and ability to detect down to the species level. This retrospective study aims to evaluate the qPCR Onycho+ test for dermatophyte detection using remnants of toenails from a cohort of patients from Puerto Rico.  Two hundred forty-two toenail samples submitted for histological examination via Periodic acid Schiff (PAS) staining for suspected onychomycosis were analyzed by the Onycho+ test and Sanger sequencing of the internal transcribed spacer (ITS-2). Compared to the gold standard Sanger sequencing method, the Onycho+ test reported an agreement of 91.39%, a sensitivity of 100% and a specificity of 84.5% in detecting dermatophytes, superior to the histology method which had a 69.53% agreement, 85.1% sensitivity and 57.1% specificity. The distribution of fungal organisms detected in this cohort shows a dermatophyte majority but a higher-than-expected proportion of NDMs. Nails negative for the Onycho+ test and positive for histology were mostly NDMs. This study demonstrates that the clinical performance of the Onycho+ test is superior to histology in detecting dermatophytes and that a combination of Onycho+ and histology can result in a higher clinical accuracy.

Contemporary Techniques and Potential Transungual Drug Delivery Nanosystems for The Treatment of Onychomycosis

The humanoid nail is considered an exceptional protective barrier that is formed mainly from keratin. Onychomycosis is the cause of 50% of nail infections that is generally caused by dermatophytes. Firstly, the infection was regarded as a cosmetic problem but because of the tenacious nature of onychomycosis and its relapses, these infections have attracted medical attention. The first line of therapy was the oral antifungal agents which were proven to be effective; nevertheless, they exhibited hepato-toxic side effects, alongside drug interactions. Following, the opportunity was shifted to the topical remedies, as onychomycosis is rather superficial, yet this route is hindered by the keratinized layers in the nail plate. A potential alternative to overcome the obstacle was applying different mechanical, physical, and chemical methods to boost the penetration of drugs through the nail plate. Unfortunately, these methods might be expensive, require an expert to be completed, or even be followed by pain or more serious side effects. Furthermore, topical formulations such as nail lacquers and patches do not provide enough sustaining effects. Recently, newer therapies such as nanovesicles, nanoparticles, and nanoemulsions have emerged for the treatment of onychomycosis that provided effective treatment with possibly no side effects. This review states the treatment strategies such as mechanical, physical, and chemical methods, and highlights various innovative dosage forms and nanosystems developed in the last 10 years with a focus on advanced findings regarding formulation systems. Furthermore, it demonstrates the natural bioactives and their formulation as nanosystems, and the most relevant clinical outcomes.

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.

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.

Visible-Light-Activated Molecular Machines Kill Fungi by Necrosis Following Mitochondrial Dysfunction and Calcium Overload

Invasive fungal infections are a growing public health threat. As fungi become increasingly resistant to existing drugs, new antifungals are urgently needed. Here, it is reported that 405-nm-visible-light-activated synthetic molecular machines (MMs) eliminate planktonic and biofilm fungal populations more effectively than conventional antifungals without resistance development. Mechanism-of-action studies show that MMs bind to fungal mitochondrial phospholipids. Upon visible light activation, rapid unidirectional drilling of MMs at ≈3 million cycles per second (MHz) results in mitochondrial dysfunction, calcium overload, and ultimately necrosis. Besides their direct antifungal effect, MMs synergize with conventional antifungals by impairing the activity of energy-dependent efflux pumps. Finally, MMs potentiate standard antifungals both in vivo and in an ex vivo porcine model of onychomycosis, reducing the fungal burden associated with infection.

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.

Clinical Clues to Differentiate between Dermatophyte Onychomycosis (DP-OM) and Dermatophytoma-Like Traumatic Onychodystrophy (DP-TO)

Background

Dermatophytoma is a recalcitrant condition of onychomycosis (OM). It presents as a white- or yellow-colored fungal mass that appears linear/triangular or round on a nail plate. Traumatic onychodystrophy (TO) can present with dermatophytoma-like lesions. Typically, OM and TO are not clinically distinguishable. Mycological testing is the gold standard for differentiating these disorders.

Objectives

This study is aimed at differentiating between the clinical and dermoscopic factors related to dermatophytoma onychomycosis (DP-OM) and dermatophytoma-like traumatic onychodystrophy (DP-TO).

Methods

A retrospective study was conducted of patients with dermatophytoma-like nail lesions who visited the Siriraj Nail Clinic between January 2010 and July 2020. The diagnosis of DP-OM was made by direct microscopy, fungal cultures, and histopathology of nail clippings.

Results

A total of 36 nails were included in the study. Thirteen nails were DP-OM, and 23 nails were DP-TO. The demographic data and risk factors for the 2 groups were not significantly different. Dermatophytoma lesions were found on the lateral side of nails in 12 cases of DP-OM (92.3%) and 11 cases of DP-TO (47.8%; P = 0.008). DP-OM was associated with longitudinal striae adjacent to dermatophytoma (69.2% vs. 30.4%; P = 0.024), sulfur-nugget-like subungual debris (23.1% vs. 0%; P = 0.040), and scale on the ipsilateral foot (69.2% vs. 8.7%; P < 0.001). DP-TO was associated with a homogenous, whitish discoloration (47.8% vs. 7.7%; P = 0.014) and a sharp edge of the onycholytic area (43.5% vs. 0%; P = 0.005).

Conclusions

The lateral location of dermatophytoma, adjacent striae, sulfur-nugget-like debris, and scale on the ipsilateral foot were significantly associated with DP-OM. Dermoscopic examination (dorsal and hyponychium views) and foot examination are beneficial for distinguishing between DP-OM and DP-TO.

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.

Diagnosing Onychomycosis: What’s New?

An overview of the long-established methods of diagnosing onychomycosis (potassium hydroxide testing, fungal culture, and histopathological examination) is provided followed by an outline of other diagnostic methods currently in use or under development. These methods generally use one of two diagnostic techniques: visual identification of infection (fungal elements or onychomycosis signs) or organism identification (typing of fungal genus/species). Visual diagnosis (dermoscopy, optical coherence tomography, confocal microscopy, UV fluorescence excitation) provides clinical evidence of infection, but may be limited by lack of organism information when treatment decisions are needed. The organism identification methods (lateral flow techniques, polymerase chain reaction, MALDI-TOF mass spectroscopy and Raman spectroscopy) seek to provide faster and more reliable identification than standard fungal culture methods. Additionally, artificial intelligence methods are being applied to assist with visual identification, with good success. Despite being considered the ‘gold standard’ for diagnosis, clinicians are generally well aware that the established methods have many limitations for diagnosis. The new techniques seek to augment established methods, but also have advantages and disadvantages relative to their diagnostic use. It remains to be seen which of the newer methods will become more widely used for diagnosis of onychomycosis. Clinicians need to be aware of the limitations of diagnostic utility calculations as well, and look beyond the numbers to assess which techniques will provide the best options for patient assessment and management.

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.

A detailed insight on the molecular and cellular mechanism of action of the antifungal drugs used in the treatment of superficial fungal infections

Background:

Dermatomycosis, a type of fungal infection that can infect human skin, hair, and nails; day by day the growth of fungal infections ranging from superficial to systemic infection is alarming. Common causative agents included are Candida, Cryptococcus, Aspergillus, and Pneumocystis species.

Objective:

The effective treatment of the fungal infection includes the use of proper antifungal drug therapy. Antifungal drugs are classified into various classes. This paper focuses on understanding and interpreting the detailed molecular and cellular mechanism of action of various classes of an anti-fungal drug along with their important characteristics along with the safety and efficacy data of individual drugs of the particular class.

Methods:

The data selection for carrying out the respective study has been done by studying the combination of review articles and research papers from different databases like Research Gate, PubMed, MDPI, Elsevier, Science Direct, and Med Crave ranging from the year 1972 to 2019 by using the keywords like “anti-fungal agents”, “dermatophytes”, “cutaneous candidiasis”, “superficial fungal infections”, “oral candidiasis”, “amphotericin”, “echinocandins”, “azoles”, “polyenes” “ketoconazole”, “terbinafine”, “griseofulvin”, “azoles”.

Result:

Based on interpretation, we have concluded that the different classes of antifungal drugs follow the different mechanisms of action and target the fungal cell membrane, and are efficient in reducing fungal disease by their respective mechanism.

Conclusion:

The prevention and cure of fungal infections can be done by oral or topical antifungal drugs that aim to destroy the fungal cell membrane. These drugs show action by their respective pathways that are either preventing the formation of ergosterol or squalene or act by inhibiting β-1,3-glucan synthase enzyme. All the drugs are effective in treating fungal infections.

Antifungal activity of 2-Chloro-N-phenylacetamide, docking and molecular dynamics studies against clinical isolates of Candida tropicalis and Candida parapsilosis

AIMS

This study evaluated the antifungal, antibiofilm, and molecular docking of 2-Chloro-N-phenylacetamide against clinical isolates of Candida tropicalis and Candida parapsilosis.

METHODS AND RESULTS

MIC of the test drugs was determined by microdilution. A1Cl obtained MIC values ranging from 16 and 256 μg/mL. Fluconazole MIC ranging from 16 and 512 μg/mL. MIC of A1Cl showed fungicide activity, emphasizing the solid antifungal potential of this drug. An association study was performed with A1Cl and fluconazole (checkerboard), revealing indifference by decreasing. Thus, we conducted this study using A1Cl isolated. In the micromorphological assay, the test drugs reduced the production of virulence structures compared to the control (concentration-dependent effect). A1Cl inhibited in vitro biofilm formation at all concentrations tested (1/4MIC to 8xMIC) (p<0.05) and reduced mature biofilm biomass (p<0.05) against C. tropicalis and C. parapsilosis. In the ex vivo biofilm susceptibility testing (human nails fragments), A1Cl inhibited biofilm formation and reduced mature biofilm biomass (p<0.05) more than 50% at MIC. Fluconazole had a similar effect at 4xMIC. In silico studies suggest that the mechanism of antifungal activity of A1Cl involves the inhibition of the enzyme dihydrofolate reductase rather than geranylgeranyltransferase-I.

CONCLUSIONS

The results suggest that A1Cl is a promising antifungal agent. Furthermore, this activity is related to attenuation of expression of virulence factors and antibiofilm effects against C. tropicalis and C. parapsilosis.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our study provides the first evidence that A1Cl, a novel synthetic drug, has fungicidal effects against C. tropicalis and C. parapsilosis. Furthermore, in vitro and ex vivo biofilms assays have demonstrated the potential antibiofilm of A1Cl. The mechanism of action involves inhibiting the enzyme dihydrofolate reductase, which was supported by in silico analyses. Therefore, this potential can be explored as a therapeutic alternative for onychomycosis and, at the same time, contribute to decreasing the resistance of clinical isolates of C. tropicalis and C. parapsilosis.

Real-life applicability of the Euroarray Dermatomycosis Kit in the diagnosis of onychomycosis

BACKGROUND

Traditionally, KOH microscopy and fungal culture are the two preferred tests as gold standard for diagnosis of onychomycosis. Recently, other diagnostic methods have been developed to improve the microbiological diagnosis. The EUROArray dermatomycosis kit is a PCR-based microarray test system for the detection and direct identification of species that are most frequently involved in skin and nail infections.

OBJECTIVES

Our primary aim was to evaluate the real-life applicability of the EUROArray dermatomycosis kit in the diagnosis of onychomycoses. In addition, we compared the etiology of onychomycoses found in our patients with those described in the literature.

PATIENTS/METHODS

We prospectively studied consecutive 100 patients with suspected onychomycoses. Samples of suspect toenails were taken as part of routine medical management. Nail specimens were evaluated by means of 3 diagnostic methods: KOH preparation, culture and EUROArray dermatomycosis kit.

RESULTS

Onychomycosis was diagnosed in 47/100 patients who proved positive on at least one reference diagnostic test and in 49/100 patients who proved positive on PCR. The combination of microscopy and PCR had better sensitivity than microscopy (p=0.0397), fungal culture (p=0.0061) and PCR alone (p=0 .0117). Molds were more frequently positive in culture than in PCR (p=0.033). Dermatophytes proved positive more frequent than molds and yeasts in both culture and PCR; in particular, Trichophyton interdigitale was the most frequent pathogen.

CONCLUSIONS

In conclusion, introducing EUROArray dermatomycosis kit into the diagnostic algorithm of onychomycosis increases the sensitivity of direct microscopy and yields more rapid results than culture.

The burden of serious fungal infections in Azerbaijan

Background:

Azerbaijan is an upper middle-income country in South Caucasus with an area of 86,600 km² and a total population of 10 million people and gross domestic product of US $4480 per capita. The aim of this research is to estimate fungal infection burden and highlight the problem at national and international levels.

Methods:

Fungal infection burden was estimated using data from epidemiological papers and population at risk and LIFE (Leading International Fungal Education) modelling.

Results:

The number of people living with human immunodeficiency virus (PLHIV) in 2018 was 6193, 29% of them not receiving antiretroviral therapy. Based on 90% and 20% rates of oral and oesophageal candidiasis in patients with CD4 cell count <200 µl^–1 we estimate 808 and 579 patients with oral and oesophageal candidiasis, respectively. The annual incidences of cryptococcal meningitis and Pneumocystis pneumonia are 5 and 55 cases, respectively. We estimated 2307 cases of chronic pulmonary aspergillosis (CPA), 4927 patients with allergic bronchopulmonary aspergillosis (ABPA), and 6504 with severe asthma with fungal sensitization (SAFS). Using data on chronic obstructive pulmonary diseases (COPD), lung cancer, acute myeloid leukaemia rates, and number of transplantations, we estimated 693 cases of invasive aspergillosis following these conditions. Using a low-European rate for invasive candidiasis, we estimated 499 and 75 patients with candidemia and intra-abdominal candidiasis respectively. The number of adult women (15–55 years) in Azerbaijan is ~2,658,000, so it was estimated that 159,490 women suffer from recurrent vulvovaginal candidiasis (rVVC).

Discussion:

In total, the estimated number of people suffering from fungal diseases in Azerbaijan is 225,974 (2.3% of the population). However, the fungal rate is underestimated due to lack of epidemiological data. The most imminent need is improvement in diagnostic capabilities. This aim should be achieved via establishing a reference laboratory and equipping major clinical centers with essential diagnostics assays.

Molecular Characterisation and Phylogenetic Analysis of Dermatophytic Fungi Isolated from Tinea Capitis in Northwest Nigeria Using Sequence of the 28S rRNA

The detection and identification of fungal DNA from clinical samples is one of the fundamental approaches in biomedicine. The incidence, distribution, and control of dermatophytes has progress significantly and the use of phylogenetic species concepts based on rRNA regions have enhanced the taxonomy of dermatophyte species; however, the use of 28S rDNA genes has certain limitations. This gene has been used in dermatophyte taxonomy with limited enumeration; we appraised the sequence disparity within and among groups of the species, the gene ranking in identification, phylogenetic analysis, and taxonomy of 32 strains of eight dermatophyte species. In this study, a set of primers was adopted to amplify the target followed by a partial sequencing of the rDNA. The utilization of a pairwise nucleotide differentiation, an affinity was observed among eight dermatophyte species, with disparity among species ranging from 0 to 197 base pair (bp). Intra-species bp differences were found within strains of Trichophyton eriotrephon, Trichophyton bullosum, Trichophyton simii (Trichophyton genus), Microsporum audouinii, and Trichophyton tonsurans (Microsporum and Trichophyton genus, respectively); however, only some strains of Trichophyton eriotrephon were found to be invariant having three genotypes. Trichophyton tonsurans exhibited most intra-species variability. The characterization and construction of a phylogenetic tree of 28S rDNA gene on dermatophyte species provide a bedrock of an additional finding of connections between species. However, 28S rRNA capture provides a novel method of effective and sensitive detection of dermatophytes lodged in human skin scale. We report for the first time the emergence of T. eriotrephon, T. bullosum, T. simii, T. benhamiae, and Ctenomyces serratus dermatophytes from Tinea capitis in Nigeria.

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.

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.

The prevalence of dermatophytoses in Brazil: a systematic review

Dermatophytosis is a common cutaneous mycosis worldwide whose prevalence in Brazil is still unknown. This systematic review has estimated the burden of dermatophytoses from updated literature data reported in the general Brazilian population. We used the following databases: Web of Science, Medline/PubMed, Embase, The Cochrane Library and Scopus for studies published between 2011 and 2020. Original articles with an emphasis on prevalence data for dermatophytosis in the Brazilian population, and diagnosed by culture exam or molecular biology were eligible. We also assessed the methodological quality of the studies. A total of 24 articles met the inclusion criteria and were reviewed. The occurrence of dermatophytoses found in the studies ranged from 4-88.50 %. The pooled prevalence of dermatophytosis for the population studies was 25 % (95 % CI: 24.7-25.3 %). The size of the samples used in the studies ranged from 45 to 36 446 participants, and ages ranged up to 98 years old. The populations studied involved mostly women. The presence of tinea unguium (toenail and fingernail) and tinea pedis were the most frequent dermatophytosis, and we observed a predominance of Trichophyton rubrum, T. interdigitale and T. mentagrophytes. The studies were primarily conducted in patient groups with suspected mycoses and were not entirely representative of the general population. Yet we believe that in the future, more collaborative strategies would improve both diagnostic capacity and epidemiological methodologies, associating the prevalence of dermatophytosis with social and environmental risk factors. This review helps to better understand future epidemiological trends in Brazil and the world.

Dermatoscopic features of onychomycosis and its correlation with nail plate potassium hydroxide mount (KOH), culture, and periodic acid schiff stain (PAS) in North East India

Context:

Dermatoscopy has been used recently for identifying the specific features of onychomycosis. Very few studies have used it as a diagnostic tool. Our study highlights the specific patterns in different clinical types of onychomycosis and the novel features that have never been reported previously.

Aims:

To study the dermatoscopic patterns in patients with onychomycosis and determine the sensitivity, specificity, positive, and negative predictive values of the different features.

Study Design:

A cross-sectional study.

Materials and Method:

Dermatoscopic picture using dinolite video dermatoscope was taken in patients diagnosed with onychomycosis either with a positive KOH, culture, and/or PAS.

Result:

A total of 80 patients were included. Onychomycosis was identified in 68 individuals. Clinically, 73.52% presented with distal lateral subungual onychomycosis (DLSO) and 26.47% had total dystrophic (TD). PAS was positive in 85.29% of patients, KOH in 75%, and culture in 66.17%. Trichophyton species were isolated in 53.33%, whereas Candida species in 40% of patients. Dermatoscopic features were seen in all 68 patients (100%). The most common finding in decreasing order includes spike pattern, ruin appearance, distal irregular terminations (DIT), longitudinal striations, chromonychia, focal homogeneous opacities, microsplitting, and uniform homogeneous pattern. Three novel patterns were observed: homogeneous opacity with a-z pattern border, microsplitting in a Christmas tree pattern, and focal homogeneous opacities.

Conclusion:

To our knowledge, this is the first study conducted in northeast India where dermatoscopy was used as a diagnostic tool and it was found to have the highest sensitivity. New features that have not been described before have been identified.

Onychomycosis: An Updated Review

Background: Onychomycosis is a common fungal infection of the nail.

Objective: The study aimed to provide an update on the evaluation, diagnosis, and treatment of onychomycosis.

Methods: A PubMed search was completed in Clinical Queries using the key term “onychomycosis”. The search was conducted in May 2019. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews published within the past 20 years. The search was restricted to English literature. Patents were searched using the key term “onychomycosis” in www.freepatentsonline.com.

Results: Onychomycosis is a fungal infection of the nail unit. Approximately 90% of toenail and 75% of fingernail onychomycosis are caused by dermatophytes, notably Trichophyton mentagrophytes and Trichophyton rubrum. Clinical manifestations include discoloration of the nail, subungual hyperkeratosis, onycholysis, and onychauxis. The diagnosis can be confirmed by direct microscopic examination with a potassium hydroxide wet-mount preparation, histopathologic examination of the trimmed affected nail plate with a periodic-acid-Schiff stain, fungal culture, or polymerase chain reaction assays. Laboratory confirmation of onychomycosis before beginning a treatment regimen should be considered. Currently, oral terbinafine is the treatment of choice, followed by oral itraconazole. In general, topical monotherapy can be considered for mild to moderate onychomycosis and is a therapeutic option when oral antifungal agents are contraindicated or cannot be tolerated. Recent patents related to the management of onychomycosis are also discussed.

Conclusion: Oral antifungal therapies are effective, but significant adverse effects limit their use.Although topical antifungal therapies have minimal adverse events, they are less effective than oral antifungal therapies, due to poor nail penetration. Therefore, there is a need for exploring more effective and/or alternative treatment modalities for the treatment of onychomycosis which are safer and more effective.

Severe onychomycosis management with oral terbinafine in a kidney transplantation setting: Clinical follow-up by image analysis

BACKGROUND

Severe onychomycosis treatment in kidney transplant recipients (KTR) is challenging because of drug interactions and adverse events. Tacrolimus remains the antirejection treatment (ART) of choice in kidney transplantation but tolerance with systemic terbinafine for the management of severe onychomycosis has not been studied.

OBJECTIVE

This study illustrates severe onychomycosis management in a kidney transplantation setting and investigates systemic terbinafine tolerance profile in KTR.

PATIENTS/METHODS

We retrospective analysed clinical data of KTR with a confirmed diagnosis of severe onychomycosis.

RESULTS

We retrieved a total of 29 KTR with severe onychomycosis needing an oral treatment to manage onychomycosis. In 55.1% (16/29) KTR, altered renal biological parameters or lack of guidelines to manage severe onychomycosis were the main reasons to deterring clinicians from prescribing oral treatments. 13 patients received an oral terbinafine treatment (9, 3 and 1 with a tacrolimus, cyclosporine and everolimus-based ART, respectively). Clinical and biological follow-up did not reveal severe drug interactions. ART blood levels showed significant variations in 2 patients without clinical consequences in renal graft. Two patients reported mild adverse events but after only one dose of terbinafine. Using an open-source image analysis program, clinical evolution of onychomycosis could be retrospectively quantified and followed up.

CONCLUSIONS

The results presented here suggest that oral terbinafine can be proposed to treat severe onychomycosis with an acceptable tolerance profile in KTR with different ART such as tacrolimus and highlight the need of multicentric studies to establish guidelines for onychomycosis treatment in KTR.

NP213 (Novexatin®): A unique therapy candidate for onychomycosis with a differentiated safety and efficacy profile

NP213 (Novexatin®) is a novel antifungal peptide specifically designed for the topical treatment of onychomycosis. NP213 was designed using host defense peptides (HDP), essential components of the innate immune response to infection, as a template. NP213 is a water-soluble cyclic fungicidal peptide that effectively penetrates human nail. NP213 demonstrated a promising preclinical and clinical safety profile, with no evidence of systemic exposure following topical application to the skin and nails. NP213 was efficacious in two phase IIa human trials with 43.3% of patients having no fungi detectable by culture of fragments from NP213-treated nails after 180 days in the first study and likewise 56.5% of patients were culture negative for dermatophytes after 360 days in the second phase IIa study. In both trials, NP213 was applied daily for only 28 days in marked contrast to other topical onychomycosis treatments that require application for up to 52 weeks. Patient reported outcomes from the phase IIa studies were positive with participants recording an improved appearance of their nails after only 14 days of application. All fungi identified in these studies were Trichophyton spp. NP213 (Novexatin®) is a promising, highly differentiated peptide-based candidate for the topical treatment of onychomycosis, addressing the infectious cause and cosmetic issues of this very common condition.

Fractional CO2-assisted photodynamic therapy improves the clinical outcome and patient's satisfaction in toenail onychomycosis treatment: an intra-patient comparative single-center study

Background: Device-based therapies have been used for onychomycosis patients with intolerance to systemic treatments. Photodynamic therapy (PDT) improves onychomycosis, while fractional carbon dioxide (FrCO₂) augments the topical drug delivery. Comparative studies between PDT alone and laser-assisted one are lacking.Objective: We aimed to evaluate the efficacy of PDT alone versus FrCO₂-assisted PDT for treatment of onychomycosis.Methods: Twenty-one patients with bilateral onychomycosis of toenails with nearly the same degree of affection were enrolled in this prospective intra-patient-controlled study. The right affected toenail was treated via PDT alone. The left toenail was treated via a FrCO₂ followed immediately by PDT. The sessions were bimonthly for a total of six sessions. Direct microscopy, fungal cultures, clinical evaluation, onychomycosis severity index scoring, and patient's satisfaction were assessed before and 12 weeks after the last session.Results: Both treatments reduced significantly the onychomycosis severity index (p < .05) without significant difference between them. The improvement in nail appearance and patient's satisfaction were higher in laser-assisted PDT than PDT alone (p < .05).Conclusion: Both treatments effectively reduced the severity of onychomycosis with a high degree of safety and tolerability. Fractional CO₂-assisted PDT enhanced the clinical outcome via improving the nail appearance and patient's satisfaction.Key messagePhotodynamic therapy has a good success rate in clearing onychomycosis. Addition of fractional CO₂ to photodynamic therapy improves the nail appearance and induces better satisfaction to treatment.

The color of skin: yellow diseases of the skin, nails, and mucosa

The colors reflected from the skin are important indicators of dermatologic and systemic disorders. Incident light is subject to absorption by chromophores in the skin and scattering. Chromophores associated with yellow light reflection include the carotenoids and bilirubin. Various pathophysiologic mechanisms associated with these and other chromophores manifest with a yellow hue on examination. This review describes these mechanisms and the clinical features of yellow skin disorders by morphology. A brief summary of the differential diagnosis, laboratory investigations, and treatments are presented. Yellow skin disorders are a heterogenous group composed of abnormalities in keratin, elastic and connective tissue, lipid metabolism, and other states of metabolic, inflammatory, or organ dysfunction. Patients will present through different routes, and skin disease may precede or follow systemic disease. Dermatologists have an essential role in identifying those with malignant or systemic associations to ensure early diagnosis and treatment.