Onychomycosis

Urea versus fractional Er:YAG laser pretreatment of methylene blue photodynamic therapy in the treatment of moderate toenail onychomycosis: short- and medium-term effects

Keratolytic properties of urea 40% have long time used for the treatment of onychomycosis. Fractional ablative lasers enhance the delivery of topically applied photosensitizers improving photodynamic therapy (PDT) efficacy. The aim of this study was to compare the short- and medium-term efficacy of a pretreatment with urea 40% and fractional Er:YAG (Fr Er:YAG) laser radiation before PDT mediated by methylene blue (MB) for moderate toenail onychomycosis. Twenty-first-toe toenails were randomized to receive either urea 40% (Group I) or Fr Er:YAG laser (Group II) pretreatment and 9 sessions of MB/PDT over the course of 16 weeks. At baseline, 28- and 40-week follow-ups, clinical efficacy was assessed by digital photographs [allowing determination of the onychomycosis severity index (OSI)], whereas mycological efficacy was assessed by histological examination and fungal culture. Details of the side effects and patients' satisfaction were also recorded. In both groups, a significant decrease in OSI values was observed at the 28-week follow-up and a slight rebound at the 40-week follow-up. The percentage of nail involvement decreased significantly in both groups at the 28-week follow-up, to continue declining gently in Group I at 40 weeks, in contrast to the rebound observed during this period in Group II. The mycological cure rate was 20% and 30% at 28-week follow-up and 70% and 40% at 40-week follow-up, in Group I and II, respectively. Patients reported being fairly satisfied, and no side effects were detected in any groups. Although both pretreatments favor the action of PDT for the treatment of onychomycosis, the use of urea at 40% is more effective in the medium term.

Fungal Nails? DNA Facts Challenge Dystrophic Etiology

BACKGROUND

Historically recalcitrant to treatment, infection of the nail unit is a pervasive clinical condition affecting approximately 10% to 20% of the US population; patients present with both cosmetic symptomatology and pain, with subsequent dystrophic morphology. To date, the presumptive infectious etiologies include classically reported fungal dermatophytes, nondermatophyte molds, and yeasts. Until now, the prevalence and potential contribution of bacteria to the clinical course of dystrophic nails had been relatively overlooked, if not dismissed. Previously, diagnosis had largely been made by means of clinical presentation, although microscopic examinations (potassium hydroxide) of nail scrapings to identify fungal agents and, more recently, panel-specific polymerase chain reaction assays have been used to elucidate causative infectious agents. Each of these tools suffers from test-specific limitations.

METHODS

Molecular-age medicine now includes DNA-based tools to universally assess any microbe or pathogen with a known DNA sequence. This affords clinicians with rapid DNA sequencing technologies at their disposal. These sequencing-based diagnostic tools confer the accuracy of DNA-level certainty, and concurrently obviate cultivation or microbial phenotypical biases.

RESULTS

Using DNA sequencing-based diagnostics, the results in this article document the first identification and quantification of significant bacterial, rather than mycotic, pathogens to the clinical manifestation of dystrophic nails.

CONCLUSIONS

In direct opposition to the prevailing and presumptive mycotic-based causes, the results in this article invoke questions about the very basis for our current standards of care, including effective treatment regimens.

[Terbinafine-resistant dermatophytoses and onychomycosis due to Trichophyton rubrum]

BACKGROUND

In recent years, therapy-refractory courses of dermatophytoses have increasingly become the focus of attention. The most frequent pathogens are Trichophyton (T.) rubrum and T. mentagrophytes. In addition to local therapy, first-line treatment includes terbinafine, an allylamine antifungal agent that acts by inhibiting squalene epoxidase and thus interfering with ergosterol synthesis. In refractory cases, terbinafine resistance due to point mutation in the squalene epoxidase gene has been frequently detected.

OBJECTIVES

The aim is to present specific aspects in the epidemiology of dermatophytoses with terbinafine resistance and to illustrate them on the basis of four patient cases including diagnostic procedures.

MATERIALS AND METHODS

A review of handbook knowledge, a selective literature search, and a review of four patient cases were performed.

RESULTS

Detection of the terbinafine resistance was performed by in vitro testing using the breakpoint method as well as sequencing of the Trichophyton isolate and detection of the point mutation with amino acid substitution at position L393F or F397L of squalene epoxidase.

CONCLUSION

In refractory and recurrent dermatophytoses, terbinafine resistance should be considered, especially in T. mentagrophytes and T. rubrum, and in vitro resistance testing of the dermatophyte and point mutation analysis of squalene epoxidase (SQLE) should be performed. Therapeutically, intermittent administration of itraconazole in combination with antifungal local therapy is recommended. Nevertheless, a recurrent course is to be expected and long-term therapy with itraconazole is usually necessary.

Treatment Outcome with Fosravuconazole for Onychomycosis

Fosravuconazole L-lysine ethanolate (F-RVCZ), a ravuconazole prodrug, is a newly available agent with high expectations for efficacy in the treatment of onychomycosis. However, clinical data regarding the efficacy of F-RVCZ are limited because the drug was launched only in Japan in 2018. Therefore, we analyzed the outcome of F-RVCZ therapy in the treatment of onychomycosis at outpatient dermatology clinics in Japan. We examined data for 109 patients (68 male, 41 female) with varying clinical type, including total dystrophic onychomycosis and dermatophytoma, and a wide range of age groups, including the elderly. The complete cure rate at 12 weeks was 6.4% (7/109) and 67.9% (74/109) at the last visit (mean time to last visit: 32 ± 14.2 weeks). Mean rate of improvement in the affected nail area was 49.1 ± 23.3% at 12 weeks and 86.8 ± 22.4% at the last visit. Efficacy at 12 weeks and the last visit, respectively, was as follows: none, 4 cases and 1 case; slight, 35 cases and 4 cases; moderate, 51 cases and 21 cases; significant, 12 cases and 9 cases; complete cure, 7 cases and 74 cases. There were no serious adverse events. This retrospective survey was the first large-scale analysis of actual clinical practice outcomes and had minimal exclusions. Compared to previous reports, our results demonstrated excellent efficacy of F-RVCZ therapy in a variety of patients. Considering our results and the ease of oral administration (1 capsule/day for 12 weeks) and few adverse events, F-RVCZ therapy appears to be a useful option for the treatment of onychomycosis.

Pestalotioid fungi: A rare agent of onychomycosis among agriculture workers

Background and Purpose:

Pestalotioid fungi are ubiquitous environmental molds that have received considerable attention in recent times not only because of their role as a plant pathogen but also owing to their high frequency of retrieval from human diseases. Regarding this, the present study was conducted to investigate onychomycosis caused by pestalotioid fungi, commonly considered important phytopathogens causing grey blight disease in Camellia sinensis.

Materials and Methods:

A total of 122 agriculture workers were enrolled from Assam, India. Direct microscopic examination was carried out using 40% KOH to determine the presence of any fungal element. Further processing of the specimens for the isolation of fungi was performed using the standard protocol. In addition, the keratinolytic potential of the isolates was evaluated by means of the in vitro hair perforation test.

Results:

Out of 103 culture-positive samples, non-dermatophyte and dermatophyte molds constituted 82.52% (n=85) and 6.79% (n=7) of the samples, followed by yeasts (n=1, 0.9%) and sterile hyphae (n=10, 9.7%). With regard to the isolated non-dermatophyte molds (82.69%), 4 cases belonged to pestalotioid fungi, such as Neopestalotiopsis piceana (n=1), Pestalotiopsis species (n=1), and Pseudopestalotiopsis theae (n=2). The keratinolytic activity of Pestalotiopsis species showed perforation by disrupting the hair cortex; furthermore, macroconidia were found to be present inside the human hair.

Conclusion:

A high rate of NDM isolation may be attributed to constant exposure to adverse environmental and occupational hazards. This study highlighted the importance of “pestalotioid fungi” as the rare etiologic agent of onychomycosis. Another remarkable finding was the keratinolytic potential of Pestalotiopsis species, which is unique in this study.

Once Weekly Application of Urea 40% and Bifonazole 1% Leads to Earlier Nail Removal in Onychomycosis

Introduction

Onychomycosis is a chronic nail fungal infection resulting in nail damage and a decreased quality of life. Chemical avulsion of the nail with urea and bifonazole -removes fungally infected debris, increasing antifungal treatment efficacy and penetration. Previous clinical ob-servations describe patients who applied their urea and -bifonazole ointment less frequently, achieving earlier nail removal. In this study, we analyzed the relationship between duration of urea and bifonazole application and time to nail avulsion.

Methods

χ² tests, multiple regression analysis, and ANOVA were performed to analyze the similarities between treatment regimens (daily, every 3 days, or once a week), association of regimens or patient characteristics to nail removal, and compare time to nail removal between each regimen, respectively.

Results

Daily application of ointment and sealing resulted in an average length of time (±SD) to nail removal of 18.7 days (±6.8 days); once every 3 days resulted in nail removal at 12.7 days (±6.2 days) and once per week at 11 days (±4.46 days) (p < 0.001). Age was the only patient factor that affected duration to nail removal.

Conclusion

Once weekly application of ointment with sealing for a 1-week duration is associated with a decrease in time to complete chemical avulsion of the nail by approximately 1 week.

Antifungal efficacy of liquid poloxamer 407-based emulsions loaded with sertaconazole nitrate

Drug delivery into the human nail plate for the treatment of onychomycosis is difficult due to limited permeability of the nail plate. Semisolid poloxamer 407-based formulations have recently shown promising results for drug delivery into and through the nail plate. In this study, liquid poloxamer 407-based emulsions loaded with sertaconazole nitrate have been developed and the permeation behavior was determined in vitro using modified Franz diffusion cells. The antifungal efficacy was evaluated in an infected nail plate model, where the growth inhibition of Trichophyton rubrum was observed. Bovine hoof plates and keratin films made from human hair were used as models for the human nail plate. In both cases, formulations with low viscosity and high water content showed best results despite a lower solubility of sertaconazole nitrate, suggesting that the composition of the vehicle plays a major role in permeation through the membrane. In addition, an API content close to saturation solubility had a positive effect on permeation.

Occurrence of dermatophytoses in patients from the Sistema Único de Saúde

BACKGROUND

Dermatophytosis is a cutaneous disease caused by filamentous keratinophilic fungi belonging to the genera Trichophyton, Microsporum and Epidermophyton, which present a high prevalence in the general population, being among the most common mycoses affecting about 20% of the world's population.

OBJECTIVE

To carry out the epidemiological survey of cases of dermatophytosis in patients from the Sistema Único de Saúde in a regional Laboratory in the period of 5 years (2009 to 2013).

METHODS

A retrospective study (January 2009 to December 2013) was carried out with a qualitative and quantitative design, through the registry book of the laboratory, Mycology Sector, where cases of patients with suspected dermatomycosis were analyzed.

RESULTS

In a 5-year period, a total of 4467 cases were suspected of having a fungal infection. Of these, 68.74% (3071) cases were of dermatomycosis. In relation to cultures with fungal growth, 12.54% (385 cases) were dermatophyte fungi and 7.97% (245 cases) non-dermatophyte fungi were isolated. Among the species identified, there was a higher prevalence of T. rubrum complex (75%), T. mentagrophytes complex (11.68%) and M. canis (7.01%). Regarding the sites analyzed, nail involvement was the most frequent in 75% of the cases.

STUDY LIMITATIONS

This work is representative in the studied region.

CONCLUSIONS

Dermatomycosis samples are the most frequent among all samples of fungal infections from these patients, with the nail being the most affected area and the fungi T. rubrum complex and T. mentagrophytes complex the most frequent.

Epidemiological survey of onychomycosis pathogens in Japan by real-time PCR

In Japan, an epidemiological survey of onychomycosis pathogens was performed using culture methods; however, the positive culture rate was 40% or less. As part of an epidemiological survey of dermatomycoses in Japan, we overcame this low positive rate by employing a real-time polymerase chain reaction (PCR) assay that allowed rapid and accurate detection and identification. In 2011, nail specimens were collected from patients at nine institutes in various prefectures in Japan and diagnosed as onychomycosis. For the detection and identification of the main pathogens causing onychomycosis, we performed real-time PCR using specific TaqMan® MGB probes and primer sets. Of the 496 onychomycosis samples, real-time PCR detected 382 cases (77.0%) caused by Trichophyton rubrum; 74 cases (15.0%) caused by Trichophyton interdigitale; and eight cases (1.6%) caused by Candida albicans. The real-time PCR positive rate was 96.2%. The most frequent pathogen was T. rubrum throughout life, with the number of patients affected peaking in the range of 60 to 69 years of age and no significant differences in the composition of causative pathogens by sex. We were able to detect and identify pathogens from almost all specimens and succeeded in analyzing the pathogens involved in onychomycosis cases in Japan. These data confirmed that our real-time PCR method was effective for detecting and identifying the main fungal pathogens from onychomycosis specimens.

An exploration of the optimum dosage and number of cycles of itraconazole pulse therapy for severe onychomycosis

Although standard itraconazole pulse therapy is a well-established regimen for toenail onychomycosis, the cure rate for onychomycosis remains low. To evaluate the efficacy and safety of different cycles of itraconazole pulse therapy, determine the optimal dosage and number of cycles for onychomycosis. A total of 90 outpatients of our hospital with onychomycosis were randomised into three treatment groups: (1) standard itraconazole pulse therapy (200 mg twice per day, 1 week each month for three pulses); (2) long-term pulse therapy (200 mg twice per day, 1 week each month for six pulses); (3) low-dose and long-term pulse therapy (200 mg/d, 1 week per month for six pulses) and were followed up for 15 months. Of the initial patients, the trial was completed by 81 patients. The complete cure rates were 32.43% for three cycles and 75% for six cycles (P < .001). For six cycles, despite the administration of half-dose for patients weighing no more than 55 kg, there was no statistical difference in the complete cure rate (P = .862). Long-term therapy is effective and safe for the treatment of toenail onychomycosis. For patients weighing no more than 55 kg, long-term half-dose itraconazole pulse therapy is recommended .

Benzoxaborole compounds for therapeutic uses: a patent review (2010- 2018)

INTRODUCTION

Benzoxaborole is a versatile boron-heterocyclic scaffold which has found in the last 10 years a broad spectrum of applications in medicinal chemistry, due to its physicochemical and drug-like properties. Use of benzoxaborole moiety in the design of compounds led to the discovery of new classes of anti-bacterial, anti-fungal, anti-protozoal, anti-viral as well as anti-inflammatory agents with interesting drug development perspectives.

AREAS COVERED

This article reviews the patent literature as well as chemistry literature during the period 2010-2018 where in several benzoxaborole derivatives with therapeutic options were reported.

EXPERT OPINION

Two benzoxaborole derivatives are already clinically used for the treatment of onychomycosis (tavaborole) and atopic dermatitis (crisaborole), with several others in various phases of clinical trials. By inhibiting enzymes essential in the life cycle of fungal, protozoan, bacterial and viral pathogens, it is probable that other compounds may soon enter the armamentarium of anti-infective agents. On the other hand, phosphodiesterase 4 seems to be the human target responsible of the anti-inflammatory action of some benzoxaboroles. The chemical versatility, peculiar mechanism of action related to the electron deficient nature of the boron atom, and ease of preparation make benzoxaboroles a highly interesting field for the pharmaceutical industry.

The Diagnosis and Treatment of Nail Disorders

BACKGROUND

Nail disorders can arise at any age. About half of all nail disorders are of infectious origin, 15% are due to inflammatory or metabolic conditions, and 5% are due to malignancies and pigment disturbances. The differential diagnosis of nail disorders is often an area of uncertainty.

METHODS

This review is based on publications and guidelines retrieved by a selective search in PubMed, including Cochrane reviews, meta-analyses, and AWMF guidelines.

RESULTS

Nail disorders are a common reason for derma - tologic consultation. They are assessed by clinical inspection, dermatoscopy, diagnostic imaging, microbiological (including mycological) testing, and histopathological examination. Some 10% of the overall population suffers from onychomycosis, with a point prevalence of around 15%. Bacterial infections of the nails are rarer than fungal colonization. High-risk groups for nail disorders include diabetics, dialysis patients, transplant recipients, and cancer patients. Malignant tumors of the nails are often not correctly diagnosed at first. For subungual melanoma, the mean time from the initial symptom to the correct diagnosis is approximately 2 years; this delay is partly responsible for the low 10-year survival rate of only 43%.

CONCLUSION

Evaluation of the nail organ is an important diagnostic instrument. Aside from onychomycosis, which is a common nail disorder, important differential diagnoses such as malignant diseases, drug side effects, and bacterial infections must be considered.

Epidemiologic Analysis of Onychomycosis in the San Diego Pediatric Population

BACKGROUND

Onychomycosis (OM) is thought to be a rare disease in children, although there are few epidemiologic studies.

METHODS

This 3-year retrospective case series of nearly 400 children seen at Rady Children's Hospital-San Diego (RCHSD) describes the characteristics of OM found in this pediatric population.

RESULTS

From 2011 to 2013, the Pediatric and Adolescent Dermatology Clinic at RCHSD saw a total of 36,634 unique patients, of whom 433 were unique patients with OM. Thirty-four patients met exclusion criteria, leaving 399 (1.1%) with a diagnosis of OM by a pediatric dermatologist. Nail cultures were obtained in 242 cases (60.7%), 116 (48.0%) of which were positive. Trichophyton rubrum was the most commonly isolated pathogen, responsible for 106 cases (91.3%) of positive cultures in the cohort.

CONCLUSIONS

Our study provides important regional information regarding epidemiologic data in pediatric onychomycosis, highlighting the diagnostic methods most commonly used and the pathogens most frequently encountered in our practice.

Efinaconazole 10% solution in the treatment of onychomycosis of the toenails

BACKGROUND

Efinaconazole 10% solution is a new triazole antifungal agent developed for the topical treatment of onychomycosis. This article reviews the pooled results of the two pivotal clinical trials of this drug that have been performed in the United States, Canada, and Japan.

METHODS

The two studies of 1,655 patients were both double-blind, vehicle-controlled, parallel-group, randomized, multicenter studies designed to determine the efficacy and safety of efinaconazole 10% solution in the treatment of mild-to-moderate onychomycosis of the toenails caused by dermatophytes. Treatment was provided once daily for 48 weeks, and the primary end point was at week 52.

RESULTS

The combined results show a 56% mycologic cure rate compared with 17% for vehicle at week 52. Clinical treatment success was achieved in 43% of patients treated with efinaconazole 10% solution at follow-up (week 52). Clinical treatment success was achieved in 47% of patients. As expected for a topical agent, the use of efinaconazole 10% solution was found to be safe, with mild, transient irritation at the site of application reported as the most common adverse event.

CONCLUSIONS

The efficacy and safety profile of efinaconazole 10% solution suggests that it may represent an important advance in the topical treatment of onychomycosis. Further studies will help us better understand the role of this agent for the treatment of this widespread podiatric medical condition.

Onychomycosis: features external therapy

Onychomycosis - one of the most frequent diseases with defeat of a nail bed, matrics and nail plate of a fungal origin. Frequency of an onychomycosis in Russia reaches 5% (to 15 million people), and practically every tenth visit of the dermatologist is connected with this pathology. Treatment of an onychomycosis still remains very difficult task. Application of varnishes, ointments with antimycotics and local agents on an oil basis has an essential shortcoming - insufficient receipt of a preparation to the center of pathological changes. It is supposed that for optimum therapy it is necessary to influence: first, from frontal and distal part of a nail, secondly, to apply aqueous-alcoholic solutions of a preparation which can freely get into subnail spaces with the phenomena of an onycholysis. For example, it has been shown highly efficient application of naftifina a hydrochloride under control of solution of the diamond green, showing diffusion distribution active ingredient to subnail space and on channels.

Onychomycosis: Practical Approaches to Minimize Relapse and Recurrence

INTRODUCTION

Toenail onychomycosis is a common disease in which treatment options are limited and treatment failures and disease recurrence are frequently encountered. It usually requires many months of treatment, and recurrence may occur in more than half of the patients within 1 year or more after the infection has been eradicated. Data on long-term treatment, follow-up and recurrence are limited.

OBJECTIVE

Our objective is to interpret these data and recommend practical approaches that should minimize recurrence based on our clinical experience.

RESULTS

Several factors have been suggested to play a role in the high incidence of recurrence, but only the extent of nail involvement and co-existing diabetes mellitus have been shown to have a significant impact.

CONCLUSION

The use of topical antifungals to prevent recurrences after complete cure was achieved has been suggested by various workers and used successfully in our practice. However, it has never been validated through clinical studies. Topical prophylaxis once weekly or twice monthly would seem appropriate in those patients most at risk. Prompt treatment of tinea pedis is essential, as is ensuring family members are free from disease. Patient education and pharmacologic intervention are equally important, and there are a number of simple strategies patients can employ. Managing onychomycosis is a significant long-term commitment for any patient, and minimizing recurrence is critical to meet their expectations.

Self-Driven Jamming in Growing Microbial Populations

In natural settings, microbes tend to grow in dense populations [1-4] where they need to push against their surroundings to accommodate space for new cells. The associated contact forces play a critical role in a variety of population-level processes, including biofilm formation [5-7], the colonization of porous media [8, 9], and the invasion of biological tissues [10-12]. Although mechanical forces have been characterized at the single cell level [13-16], it remains elusive how collective pushing forces result from the combination of single cell forces. Here, we reveal a collective mechanism of confinement, which we call self-driven jamming, that promotes the build-up of large mechanical pressures in microbial populations. Microfluidic experiments on budding yeast populations in space-limited environments show that self-driven jamming arises from the gradual formation and sudden collapse of force chains driven by microbial proliferation, extending the framework of driven granular matter [17-20]. The resulting contact pressures can become large enough to slow down cell growth, to delay the cell cycle in the G1 phase, and to strain or even destroy the microenvironment through crack propagation. Our results suggest that self-driven jamming and build-up of large mechanical pressures is a natural tendency of microbes growing in confined spaces, contributing to microbial pathogenesis and biofouling [21-26].

Mycology - an update Part 3: Dermatomycoses: topical and systemic therapy

Treatment of dermatophyte infections is based on the clinical picture and mycological detection of the causative pathogen. Based on the appropriate indication, onychomycosis can be treated topically using an antimycotic nail lacquer. Atraumatic nail abrasion with 40 % urea ointment has a beneficial effect on healing. Continuous treatment of onychomycosis with terbinafine represents the most effective systemic therapy. Terbinafine or itraconazole are the safest and most effective antimycotic agents for the treatment of onychomycosis in children. For laser therapy of onychomycosis, only a few studies on clinical efficacy are available. Regarding tinea capitis, targeted species-specific therapy of dermatophytosis of the scalp is currently recommended. Terbinafine, yet also itraconazole and fluconazole, are effective in tinea capitis caused by Trichophyton species. Microsporum infections of the scalp are preferably treated with griseofulvin, alternatively with itraconazole or fluconazole. Terbinafine is less effective. Candidal intertrigo are topically treated with nystatin, but azoles or ciclopirox olamine are also suitable candidates. Systemically, fluconazole or itraconazole are used. Topical and systemic antimycotics are equivalent forms of therapy in acute vulvovaginal mycosis. Fluconazole is the drug of choice in chronic recurrent vulvovaginal mycosis caused by Candida albicans. Ketoconazole shows very good efficacy in tinea versicolor. With respect to systemic treatment of severe and widespread tinea versicolor, itraconazole is the drug of choice.

Evaluation of improvement of onychomycosis in HIV-infected patients after initiation of combined antiretroviral therapy without antifungal treatment

Onychomycosis in HIV-infected patients has a prevalence of 20-44% and is more frequently seen with CD4(+) T cell counts ≤450 cel μl(-1). There are case reports of improvement in onychomycosis after initiation of combined antiretroviral therapy (cART), but there are no prospective studies that prove the existence and frequency of this phenomenon. The aim of this study was to evaluate if HIV-infected patients with onychomycosis who begin cART improve and/or cure without antifungal treatment. We included HIV-infected patients with onychomycosis who had not started cART and nor received antifungal therapy during 6 months prior to the study. We evaluated affected the nails with the Onychomycosis Severity Index (OSI); nail scrapings were collected and direct microscopy with potassium hydroxide (KOH) as well as mycological culture were performed. We repeated these procedures at 3 and 6 months to assess changes. CD4 T cell counts and HIV viral load were obtained. A total of 16 patients were included, with male gender predominance (68.7%); distal and lateral subungual onychomycosis (DLSO) was the most common form (31.3%). Trichophyton rubrum was the most frequently isolated microorganism. OSI decreased 21.5% at 3 months and 40% at 6 months after initiation of antiretrovirals (P = 0.05). We found a non-significant tendency towards improvement with higher CD4(+) T cell counts and with viral loads <100 000 copies ml(-1). This could be due to the increase in CD4(+) T cells, decreased percentage of Treg (CD4(+)CD25(+)) among CD4(+) Tcells and/or a decreased viral load; further studies are necessary to prove these hypothesis.

Descriptive study of onychomycosis in a hospital in São Paulo

Onychomychosis, a nail fungus infection is the most frequent nail ailment, constituting about half of all nail disorders. It can be caused by dermatophytes, non-dermatophytes, yeasts and Prothoteca spp. Methods include 5407 samples of patients with suspected onychomycosis, studied from January 2002 to December 2006, by direct mycological examination and fungi culture. The diagnosis of onychomycosis was confirmed in samples from 3822 direct mycological and/or culture positive. The diagnosis was established by culture for fungi. Among the 1.428 identified agents, the dermatophytes were responsible for 68.6% (N = 980) of cases, followed by yeasts with 27.6% (N = 394), non-dermatophytes fungi with 2.2% (N = 31), Prothoteca spp with 0.1% (N = 2), and associations with 1.5% (N = 22). Females were more affected, with 66% (N = 2527) of cases, and the most affected age group ranged from 31 to 60 years of age (median 47 years). Fungal microbiota is often changed in the world, both quantitatively and qualitatively, and is affected by several environmental factors. Thus, the periodic review of the composition of this microbiota is important to evaluate the epidemiology and thus proportion a better therapeutic response.

The prevalence of culture-confirmed toenail onychomycosis in at-risk patient populations

Onychomycosis is a fungal infection of the nail and is the most common nail affliction in the general population. Certain patient populations are at greater risk of infection and the prevalence of onychomycosis reported in the literature has yet to be summarized across these at-risk groups. We performed a systematic review of the literature and calculated pooled prevalence estimates of onychomycosis in at-risk patient populations. The prevalence of dermatophyte toenail onychomycosis was as follows: general population 3.22% (3.07, 3.38), children 0.14% (0.11, 0.18), the elderly 10.28% (8.63, 12.18), diabetic patients 8.75% (7.48, 10.21), psoriatic patients 10.22% (8.61, 12.09), HIV positive patients 10.40% (8.02, 13.38), dialysis patients 11.93% (7.11, 19.35) and renal transplant patients 5.17% (1.77, 14.14). Dialysis patients had the highest prevalence of onychomycosis caused by dermatophytes, elderly individuals had the highest prevalence of onychomycosis caused by yeasts (6.07%; 95% CI = 3.58, 10.11) and psoriatic patients had the highest prevalence of onychomycosis caused by non-dermatophyte moulds (2.49%; 95% CI = 1.74, 3.55). An increased prevalence of onychomycosis in certain patient populations may be attributed to impaired immunity, reduced peripheral circulation and alterations to the nail plate which render these patients more susceptible to infection.

Efinaconazole topical solution, 10%: the development of a new topical treatment for toenail onychomycosis

BACKGROUND

Toenail onychomycosis is a common disease with limited treatment options; treatment failure and relapse are frequently encountered. Many patients experience long-standing disease affecting multiple toenails, with substantial discomfort and pain. Although some patients might prefer a topical therapy, efficacy with ciclopirox nail lacquer has been disappointing.

METHODS

Efinaconazole topical solution, 10% is the first topical triazole antifungal agent specifically developed for the treatment of onychomycosis. This paper reviews the preclinical and clinical data on efinaconazole topical solution, 10%.

RESULTS

Efinaconazole has a broad spectrum of antifungal activity in vitro and is more potent than ciclopirox against common onychomycosis pathogens. It has a more optimal keratin affinity than ciclopirox, and it exhibits significantly greater in vivo activity owing to its superior nail penetration. Mycologic cure rates at week 52 were 55.2% (study 1) and 53.4% (study 2) with efinaconazole topical solution, 10% compared with 16.8% and 16.9%, respectively, with vehicle (P<.001 for both). In addition, efinaconazole is well tolerated.

CONCLUSIONS

Efinaconazole topical solution, 10% may likely become a preferred topical agent for the management of mild-to-moderate onychomycosis.

Potential role of tavaborole for the treatment of onychomycosis

ABSTRACT 

Systemic antifungal treatments are believed to be more effective than topicals for the treatment of onychomycosis; however, they are associated with more risks of adverse events. Tavaborole is the first member of a new class of antifungals that has been developed as a new topical nail solution for the treatment of toenail onychomycosis caused by dermatophytes. During Phase I–III clinical trials, tavaborole 5.0% nail solution showed a favorable safety and efficacy profile. Tavaborole 5.0% received US FDA market approval on 8 July 2014.

The unique chemistry of benzoxaboroles: current and emerging applications in biotechnology and therapeutic treatments

Benzoxaboroles have garnered much attention in recent years due to their diverse applications in bio-sensing technology, material science, and therapeutic intervention. Part of the reason arises from the benzoxaboroles' unique chemical properties, especially in comparison to their acyclic boronic acid counterparts. Furthermore, the low bio-toxicity combined with the high target specificity associated with benzoxaboroles make them very attractive as therapeutic agents. Herein, we provide an updated summary on the current knowledge of the fundamental chemical reactivity of benzoxaboroles, followed by highlighting their major applications reported to date.

Morphopathological aspects of healthy nails and nails affected by onychomycosis

Patients of onychomycosis are common in the dermatology practice. Contemporary morphology creates opportunities to study the functional units of the nail when such infections occur from morphopathological point of view. There were 22 nails biopsies from onychomycosis patients taken for the research of morphopathological changes in the thickened nail plate affected by onychomycosis. Samples of cadaverous' nails were used as a control material. The material was stained with haematoxylin and eosin and immunohistochemical methods. Terminal deoxynucleotidyl transferase dUTP nick end labelling reaction and periodic acid-Schiff reaction were also performed. We found patchy hypertrophy in the granulose layer of the epidermis, with focal acanthosis. In the horn layer, we identified nests of parakeratosis of various sizes, with incorporations of homogenous and eosinophil masses. We found high levels of interleukin 6 and interleukin 10 positive cells in the nail bed and in the bloodstream. Interleukin 1, however, was not a part of any of the functional units of any of the nails. Significant amount of fibres containing human beta defensin-2 were found in the bed and plate of the nail. Therefore one can conclude that as regards the nails affected by onychomycosis, the most effective morphopathogenical processes include cytokine and defensin excretion occurrence in the nail bed.

An investigation into the inhibitory effect of ultraviolet radiation on Trichophyton rubrum

Fungal infection of nails, onychomycosis, is predominantly caused by Trichophyton rubrum. This infection is an important public health concern due to its persistent nature and high recurrence rates. Alternative treatments are urgently required. One such alternative is phototherapy involving the action of photothermal or photochemical processes. The aim of this novel study was to assess which wavelengths within the ultraviolet (UV) spectrum were inhibitory and equally important nail transmissible. Initial irradiations of T. rubrum spore suspensions were carried out using a tunable wavelength lamp system (fluence ≤3.1 J/cm(2)) at wavelengths between 280 and 400 nm (UVC to UVA) to evaluate which wavelengths prevented fungal growth. Light-emitting diodes (LEDs) of defined wavelengths were subsequently chosen with a view to evaluate and potentially implement this technology as a low-cost "in-home" treatment. Our experiments demonstrated that exposure at 280 nm using an LED with a fluence as low as 0.5 J/cm(2) was inhibitory, i.e., no growth following a 2-week incubation (p < 0.05; one-way ANOVA), while exposure to longer wavelengths was not. A key requirement for the use of phototherapy in the treatment of onychomycosis is that it must be nail transmissible. Our results indicate that the treatment with UVC is not feasible given that there is no overlap between the antifungal activity observed at 280 nm and transmission through the nail plate. However, a potential indirect application of this technology could be the decontamination of reservoirs of infection such as the shoes of infected individuals, thus preventing reinfection.

Aspergillus terreus complex: an emergent opportunistic agent of Onychomycosis

The incidence of onychomycosis due to non-dermatophyte moulds (NDM) is increasing. Aspergillus terreus is relatively undocumented as an agent of this fungal infection. The aim of this work is to show the prevalence of onychomycosis caused by A. terreus and to describe its clinical features. Nail samples were collected for microscopic examination and culturing in selective media. All cases of onychomycosis due to NDM were confirmed by a second sample. Aspergillus terreus isolates were identified through their morphological characteristics and using molecular methods. A total of 2485 samples were obtained. Positive cultures were obtained in 1639 samples. From 124 NDM confirmed cultures, 23 were identified as A. terreus (18.5%). Superficial white onychomycosis was the most frequent clinical pattern. A high percentage was found in fingernails. The prevalence of A. terreus in this study considerably exceeded the percentages reported by other authors. Onychomycosis due to A. terreus presents similar clinical patterns to those caused by dermatophytes, but is difficult to eradicate and is associated with less predictable treatment outcomes. Better knowledge of the aetiology of A. terreus may be important for accomplishing more accurate and effective treatment.

Histopathological periodic acid-schiff stains of nail clippings as a second-line diagnostic tool in onychomycosis

The diagnosis of onychomycosis, using direct microscopy and fungal cultures, is often negative despite the presence of disease. Periodic acid-Schiff (PAS) staining of nail clippings, using histopathological processing, may be positive in these cases. It is not always clear, however, whether the fungal elements detected by PAS staining are pathogenic fungi or some are saprophytes. We aimed to study the efficacy of histopathological PAS staining of nail clippings as a second-line diagnostic tool in onychomycosis. The study included 100 consecutive cases in which direct microscopy and fungal cultures from suspected onychomycosis were negative on one occasion or more. The obtained nail clippings were processed for routine histology, stained with hematoxylin and eosin and PAS, and examined microscopically. Of the 100 cases, 38 (38%) showed positive fungal elements. As a result, 9 patients had sought and received oral antifungal therapy and all achieved complete clinical cure. The histological examination also revealed parakeratosis and globules of plasma, which were statistically significantly more common in the fungal infected nail samples. This may indicate an ongoing inflammatory process associated with onychomycosis. Neutrophils and bacteria were not statistically and significantly more common in the fungal infected nails. We conclude that as a second-line diagnostic tool, PAS stain of nail clippings increases markedly the diagnostic yield of onychomycosis and, consequently, the outcome of therapy.

[Fungal nail infections--an update: Part 1--Prevalence, epidemiology, predisposing conditions, and differential diagnosis]

Onychomycosis describes a chronic fungal infection of the nails most frequently caused by dermatophytes, primarily Trichophyton rubrum. In addition, yeasts (e. g. Candida parapsilosis), more rarely molds (Scopulariopsis brevicaulis), play a role as causative agents of onychomycosis. However, in every case it has to be decided if these yeasts and molds are contaminants, or if they are growing secondarily on pathological altered nails. The point prevalence of onychomycosis in Germany is 12.4%, as demonstrated within the "Foot-Check-Study", which was a part of the European Achilles project. Although, onychomycosis is rarely diagnosed in children and teens, now an increase of fungal nail infections has been observed in childhood. More and more, diabetes mellitus becomes important as significant disposing factor both for tinea pedis and onychomycosis. By implication, the onychomycosis represents an independent and important predictor for development of diabetic foot syndrome and foot ulcer. When considering onychomycosis, a number of infectious and non-infectious nail changes must be excluded. While psoriasis of the nails does not represent a specific risk factor for onychomycosis, yeasts and molds are increasing isolated from patients with psoriatic nail involvement. In most cases this represents secondary growth of fungi on psoriatic nails. Recently, stigmatization and impairment of quality of life due to the onychomycosis has been proven.

Confocal laser scanning microscopy as a new valuable tool in the diagnosis of onychomycosis - comparison of six diagnostic methods

Onychomycosis is common and can mimic several different nail disorders. Accurate diagnosis is essential to choose the optimum antifungal therapy. The aim of this study was to evaluate the use of confocal laser scanning microscopy (CLSM) and optical coherence tomography (OCT) as new non-invasive diagnostic tools in onychomycosis and to compare them with the established techniques. In a prospective trial, 50 patients with suspected onychomycosis and 10 controls were examined by CLSM and OCT. Parallel KOH preparation, culture, PAS-staining and PCR were performed. PCR showed the highest sensitivity, followed by CLSM, PAS and KOH preparation. OCT offered the second best sensitivity but displayed the lowest specificity. CLSM and KOH preparation showed a high specificity and CLSM offered the best positive predictive value, similar to KOH preparation and OCT. Fungal culture showed the lowest sensitivity and the worst negative predictive value, yet culture and PCR are the only techniques able to identify genus and species. In summary, CLSM was comparable to PAS staining and superior to KOH preparation. Due to the low specificity we assess OCT not as appropriate. In the differentiation of species PCR outplays the fungal culture in terms of time and sensitivity.

Antifungal susceptibility patterns of yeasts and filamentous fungi isolated from nail infection

BACKGROUND

Onychomycosis is the nail infection caused by a wide spectrum of fungi species, including yeasts, dermatophytes and filamentous fungi non-dermatophytes (FFND). This fungal infection represents an important medical problem because it involves the patient's life quality.

OBJECTIVE

The aim was to isolate and identify the fungal agents of onychomycosis, and to determine the in vitro susceptibility to antifungal agents.

METHODS

During the period of March 2008 to March 2009, 114 patients clinically suspected of having onychomycosis were examined. Demographic data, mainly age and gender were obtained from each patient. The nail samples collected (136) were submitted to direct examination with potassium hydroxide 20% and grown on Sabouraud dextrose agar. The in vitro antifungal susceptibility testing was performed according to the method of broth microdilution, recommended by the Clinical Laboratory Standards Institute (CLSI).

RESULTS

Onychomycosis was observed in 95 (83.3%) patients, including 16 men (16.8%) and 79 women (83.2%), with mean age of 48.1 years. Candida parapsilosis, Trichophyton rubrum and Fusarium spp were the fungi most frequently isolated. The most of the isolated yeasts showed susceptibility to antifungal agents studied. Among filamentous fungi, high MIC values to itraconazole were found for T. rubrum and T. mentagrophytes, while Fusarium spp showed decreased susceptibility to itraconazole and voriconazole.

CONCLUSION

C. parapsilosis was the most common fungal species isolated from patients with onychomycosis. The different response obtained by in vitro susceptibility testing to drugs shows the importance of these methods to assist clinicians in choosing the best therapeutic option.

Clinical diagnosis of toenail onychomycosis is possible in some patients: cross-sectional diagnostic study and development of a diagnostic rule

BACKGROUND

Suspected toenail onychomycosis is a frequent problem. Clinical diagnosis has been considered inadequate.

OBJECTIVES

To assess the diagnostic accuracy of clinical findings for detecting fungi in toenails, and to develop and validate a clinical diagnostic rule aimed at improving dermatologists' diagnosis of onychomycosis.

METHODS

A cross-sectional diagnostic study was performed including a total of 277 patients seen by 12 dermatologists. The gold standard was the presence of dermatophytes on culture or a positive nail plate biopsy. For each sign we described prevalence, sensitivity, specificity, positive and negative predictive values, and likelihood ratios for positive and negative results. We developed a diagnostic clinical rule and validated it in a subsample.

RESULTS

Helpful findings to predict the presence of fungi are: previous diagnosis of fungal disease; abnormal plantar desquamation (affecting > 25% of the sole); onychomycosis considered the most probable diagnosis by a dermatologist; and presence of interdigital tinea. When dermatologists considered onychomycosis the most probable diagnosis and plantar desquamation was present (13% of patients), the positive predictive value for presence of fungi was 81%. When both signs were absent (34% of patients), the positive predictive value for absence of fungi was 71%. In other situations, clinical diagnosis might not give enough information to decide on therapy.

CONCLUSIONS

In 13% of the patients (a large number in absolute terms), when dermatologists consider onychomycosis the most probable diagnosis and plantar desquamation is present, therapy should be started without any further test, as clinical diagnosis is at least as accurate as laboratory tests. In other situations, an optimal management strategy should be defined.