A new classification of onychomycosis

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.

Post-Traumatic Single-Digit Onychomycosis

Onychomycoses are a group of fungal nail infections commonly classified either according to the pathogenic fungus, to the duration of the disease or to the mode of fungal invasion. Most cases are diagnosed clinically, although there is a general consensus that the pathogen should be identified prior to initiating a treatment. However, this is often difficult as the classical mycologic methods of direct microscopy and culture frequently remain negative. We came across a particular subset of onychomycoses, which posed extreme diagnostic and therapeutic challenges. Over a period of 15 years, 44 patients were seen in specialized nail clinics with a single nail dystrophy that was examined and treated in vain by many practitioners and dermatologists prior to their consultation. Of the forty-four cases, thirty-nine patients had a fingernail affected and five had a toenail affected. The nail was almost completely onycholytic, the nail bed visibly keratotic, the proximal nail fold smooth and shiny and slightly swollen. All patients except five brought the results of negative mycologic cultures. Thirty-four patients had received antifungal therapy, mostly topical, as a single nail would not qualify for systemic treatment according to most national and international guidelines. The diagnosis was finally confirmed by histopathology of the nail plate showing an invasive onychomycosis in all cases. After nail avulsion and combined topical and systemic antifungal therapy, thirty-six patients were cured, three were lost from follow-up, and five showed improved nails but not a complete clinical and mycologic cure. A single-digit nail disease raises the suspicion of a tumor or a trauma; although, in rare cases, diseases normally affecting several nails may only affect a single nail. Such a case should prompt the clinician to ask for a previous trauma to this digit and to intensify the search for a specific pathogen. This study also underlines the importance of histopathology for the diagnosis of onychomycoses.

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.

Neoscytalidium dimidiatum as onychomycosis causative agent in an Iranian patient: a case report and literature review

A 38-year-old healthy male presented to our medical mycology center with whitish opaque discoloration of the right toenail. He reported a history of some sand scratches subsequent to walking barefoot on the beach two years ago and wearing hard safety shoes for a period of two years. On clinical examination, onycholysis, onychodystrophy, and apparent thickening of the ungual bed in the left big toe were found. The microscopic examination of nail clippings using 15% potassium hydroxide (KOH/) revealed the presence of septate pigmented hyphae. The fungus was identified as Neoscytalidium dimidiatum based on the cultural characteristics, the arrangement of arthroconidia on lactophenol cotton blue (LPCB) staining, blocky-brown pigmented hyphae on serum physiology mounts, and sequencing. Susceptibility of the isolated fungi to amphotericin B, itraconazole, voriconazole, and terbinafine was tested using the standard broth microdilution M38-A2 method developed by the Clinical and Laboratory Standards Institute (CLSI). The minimum inhibitory concentrations (MICs) of the four antifungal drugs used in this study were: amphotericin B: 1 mg/L, itraconazole: 2 mg/L, voriconazole: 0.25 mg/L, and terbinafine: 1 mg/L. The patient underwent terbinafine and clobetasol topical treatments for 6 months.

Nondermatophyte mould onychomycosis

Nondermatophyte moulds (NDMs) onychomycosis is often difficult to diagnose as NDMs have been considered contaminants of nails. There are several diagnostic methods used to identify NDMs, however, repeated laboratory isolation is recommended to validate pathogenicity. With NDM and mixed infection (dermatophytes plus NDM) onychomycosis on the rise, accurate clinical diagnosis along with mycological tests is recommended. Systemic antifungal agents such as itraconazole and terbinafine (e.g. pulse regimen: 1 pulse = every day for one week, followed by no treatment for three weeks) have shown efficacy in treating onychomycosis caused by various NDMs such as Aspergillus spp., Fusarium spp., Scopulariopsis brevicaulis, and Onychocola canadensis. Studies investigating topical therapy and devices for NDM onychomycosis are limited. The emergence of antifungal resistance necessitates the incorporation of antifungal susceptibility testing into diagnosis when possible, for the management of recalcitrant infections. Case studies documented in the literature show newer azoles such as posaconazole and voriconazole as sometimes effective in treating resistant NDM onychomycosis. Treatment with broad-spectrum antifungal agents (e.g. itraconazole and efinaconazole) and other combination therapy (oral + oral and/or oral + topical) may be considerations in the management of NDM onychomycosis.

Candidal Onychomycosis: Clinicoepidemiological Profile, Prevailing Strains, and Antifungal Susceptibility Pattern-A Study from a Tertiary Care Hospital

Background:

Despite an increasing trend of onychomycosis caused by Candida species in recent years, there is a scarcity of published data.

Objective:

To determine the epidemiological and clinical characteristics of Candida onychomycosis, to identify the prevalent, and perform in-vitro antifungal susceptibility testing (AFST) of the isolates.

Methodology:

A total of 506 consecutive patients with a clinical suspicion of onychomycosis were included in a cross-sectional clinical study. Nail scrapings and clippings were subjected to KOH examination and culture. Species identification and antifungal drug sensitivity testing were done for Candida isolates using Vitek 2YST Compact system using Vitek 2 cards.

Results:

Out of 384 (75.88%) culture-positive cases, dermatophytes were isolated in 58.08%, yeast in 26.30%, and NDM in 12.24%. Of the yeast, Candida albicans was isolated in 59.4% and non-albicans species in 40.59%. AFST showed that most of Candida species exhibited 100% susceptibility to most of the antifungal drugs tested, while intermediate resistance to fluconazole and flucytosine was seen in some non-albicans species (C. krusei, C. glabrata, and C. guilliermondii). Time taken for species identification was 14–18 h (average 15.5 h), while determination of minimum inhibitory concentration took 9–27 h (average 13 h).

Conclusions:

Our study showcases the present scenario of Candida distribution and the resistance patterns of various species afflicting the nail unit. Furthermore, our findings clearly indicate that the carriage of this pathogenic yeast is seen in both healthy individuals as well as with immunosuppression.

Treatment and management strategies of onychomycosis

Onychomycosis is one of the most prevalent and severe nail fungal infections, which is affecting a wide population across the globe. It leads to variations like nail thickening, disintegration and hardening. Oral and topical drug delivery systems are the most desirable in treating onychomycosis, but the efficacy of the results is low, resulting in a relapse rate of 25-30%. Due to systemic toxicity and various other disadvantages associated with oral therapy like gastrointestinal, hepatotoxicity, topical therapy is commonly used. Topical therapy improves patient compliance and reduces the cost of treatment. However, due to poor penetration of topical therapy across the nail plate, research is focused on different chemical, mechanical and physical methods to improve drug delivery. Penetration enhancers like Thioglycolic acid, Hydroxypropyl-β-cyclodextrin (HP-β-CD), Sodium lauryl sulfate (SLS), carbocysteine, N-acetylcysteine etc. have shown results enhancing the drug penetration across the nail plate. Results with physical techniques such as iontophoresis, laser and Photodynamic therapy are quite promising, but the long-term suitability of these devices is in need to be determined. In this article, a brief analysis of the treatment procedures, factors affecting drug permeation across nail plate, chemical, mechanical and physical devices used to increase the drug delivery through nails for the onychomycosis management has been achieved.

Mechanistic Insights of Formulation Approaches for the Treatment of Nail Infection: Conventional and Novel Drug Delivery Approaches

Onychomycosis is a chronic disorder that is difficult to manage and hard to eradicate with perilous trends to relapse. Due to increased prevalence of HIV, use of immunosuppressant drugs and lifestyle-related factors, population affected with fungal infection of nail (Onychomycosis) happens to increase extensively in last two decades. Modalities available for the treatment of onychomycosis include systemically administered antifungals, mechanical procedures, and topical drug therapy. But the efficacy of the most of approaches to deliver drug at targeted site, i.e., deep-seated infected nail bed is limited due to compact and highly keratinized nail structure. A series of advanced formulation approaches, such as transfersomes, liposomes, nano/micro emulsion, nail lacquers etc., have been attempted to improve the drug penetration into nail plate more efficiently. The manuscript reviews these formulation approaches with their possible mechanisms by which they improve the drug penetration.Comparative analysis of available treatment modalities for onychomycosis has been provided with pros and cons of each alternatives. Additionally, ongoing research about the application of biological materials such as modified cationic antimicrobial peptides (AMPs), plant-derived proteins, and synthetic antimicrobial peptidomimetics have also been explored.

Fusarium onychomycoses in Switzerland-A mycological and histopathological study

Onychomycoses in temperate climates are most commonly due to dermatophytes, particularly Trichophyton rubrum. Non-dermatophyte nail infections are much less frequent, and their diagnosis requires a careful and repeated search for a potential dermatophyte that may have been overgrown in culture. A series of histological slides of suspected onychomycoses with uncommon fungal morphology prompted us to search for non-dermatophytic moulds causing dermatophytosis-like nail infections. Thirty cases were identified by culture as F solani, F oxysporum, F dimerum or F spp, and two more were only diagnosed histopathologically. None of these patients was immunocompromised. Treatment was mostly unsuccessful with terbinafine whereas itraconazole showed a moderately better treatment result; in all cases, a topical ciclopirox nail varnish in a hydroxychitosan base was added.

[Onychomycosis: Practical treatment strategies]

BACKGROUND

Onychomycosis is one of the most common nail diseases with an increasing number of cases. There is always a need for therapy because fungal nail infection never shows a tendency to spontaneous self-healing. Thus, the disease belongs to core competency of dermatologists.

CONCLUSION

Successful treatment requires a correct diagnosis based on meticulous anamnesis, the clinical findings as well as the identification of the pathogen fungus. Dermatoscopy and histological examination play an important role in this context. The algorithm as presented gives a concise overview of treatment.

Clinico-aetiologic profile of Onychomycoses in a tertiary care centre in northeast India

Onychomycosis refers to fungal nail infection. Despite a clearly diseased appearance, it is often deemed a merely cosmetic problem of relatively minor importance. However, it may result in much psychological or occupational turmoil, diminished self-esteem and resulting reluctance for public interaction. A wide number of factors determine the treatment outcome and its prevalence varies greatly. Our study was conducted between January 2011 and December 2014 in northeast India. Of 243 patients presenting with nail abnormalities, 158 (65%) were positively diagnosed by either direct microscopy or culture or both. A distal lateral subungual infection was the most predominant clinical pattern observed, and the most frequent aetiological agents were dermatophytes, of which Trichophyton rubrum was predominant.

Prevalence and Epidemiology of Onychomycosis

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

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.

Use of restriction fragment length polymorphism to identify Candida species, related to onychomycosis

Background:

Onychomycosis is one of the most common clinical forms of fungal infections due to both filamentous fungi and yeasts. The genus of Candida is one of the most prominent causes of onychomycosis in all around the world. Although Candida albicans is still the most frequent cause of nail infections, use of broad-spectrum antifungal agents has led to a shift in the etiology of C. albicans to non-albicans species. The aim of the present study is rapid and precise identification of candida species isolated from nail infection by using of PCR-RFLP technique.

Materials and Methods:

A total of 360 clinical yeast strains were collected from nail infections in Iran. Genomic DNA was extracted using FTA^; cards. ITS1-5.8SrDNA-ITS2 region was amplified using universal primers and subsequently products were digested with the restriction enzyme MspI. For identification of newly described species (C. parapsilosis complex), the SADH gene was amplified, followed by digestion with Nla III restriction enzyme.

Results:

Candida albicans was the most commonly isolated species (41.1%), followed by C. parapsilosis (21.4%), C. tropicalis (12.8%), C. kefyr (9.4%), C. krusei (5.5%), C. orthopsilosis (4.1%), C. glabrata (2.8%), C. guilliermondii (1.4%), C. rugosa (0.8%), and C. lusitaniae (0.5%). Patients in the age groups of 51-60 and 81-90 years had the highest and lowest distribution of positive specimens, respectively.

Conclusion:

Rapid and precise identification of Candida species from clinical specimens lead to appropriate therapeutic plans.

Patient considerations in the management of toe onychomycosis - role of efinaconazole

Onychomycosis is a difficult diagnosis to manage and treatment is sometimes avoided, as this diagnosis is often wrongly perceived as a cosmetic problem. However, onychomycosis has a negative impact on patients' quality of life, affecting social interaction, psychological well-being, and physical activities. Onychomycosis is also a risk factor for patients with diabetes, with proven increased rates of cellulitis, gangrene, and foot ulcers. Treatments are only mild to moderately effective, and rates of relapse and reinfection are high. Oral treatments require laboratory monitoring due to risk of hepatotoxicity and may be contraindicated in some patients due to risk of drug-drug interactions. Topical treatments require prolonged application and are not very effective. Efinaconazole 10% solution is a new topical triazole treatment for mild to moderate distal subungual onychomycosis, with good efficacy and without the need for debridement of nails. In onychomycosis of the toenails, efinaconazole 10% solution is documented to have a statistically significant, positive impact on patient satisfaction and quality of life.

Tavaborole for the treatment of onychomycosis

INTRODUCTION

Onychomycosis causes approximately one-half of all nail disorders and its prevalence has been steadily increasing. It is difficult to treat, partly due to the subungual location and the inability of both oral and topical antifungals to reach the site of infection. Published cure rates with oral drugs are < 50% and even lower with topical drugs. Pathogenic factors include the diversity of fungal organisms and the difficulty of drugs penetrating the nail plate. Tavaborole is a broad-spectrum oxaborole antifungal agent with low molecular weight, permitting optimal nail plate penetration. In vitro and ex vivo studies have demonstrated the superior nail-penetrating properties of tavaborole compared to existing topical antifungal medications approved for the treatment of onychomycosis.

AREAS COVERED

The clinical characteristics and prevalence of onychomycosis, currently available treatments, and the chemistry, safety and pharmacokinetic properties of tavaborole for the treatment of onychomycosis.

EXPERT OPINION

Tavaborole is a novel, topical antifungal pharmaceutical agent pending FDA approval for the treatment of toenail onychomycosis due to dermatophytes. Efficacy has been demonstrated by a clinical development program including in vitro data and two large Phase III trials that enrolled ∼ 1200 patients. When approved, tavaborole topical solution, 5% may become a safe and effective option for the treatment of onychomycosis.

Onychomycosis in children: an experience of 59 cases

Background

Although tinea unguium in children has been studied in the past, no specific etiological agents of onychomycosis in children has been reported in Korea.

Objective

The purpose of this study was to investigate onychomycosis in Korean children.

Methods

We reviewed fifty nine patients with onychomycosis in children (0~18 years of age) who presented during the ten-year period between 1999 and 2009. Etiological agents were identified by cultures on Sabouraud's dextrose agar with and without cycloheximide. An isolated colony of yeasts was considered as pathogens if the same fungal element was identified at initial direct microscopy and in specimen-yielding cultures at a follow-up visit.

Results

Onychomycosis in children represented 2.3% of all onychomycosis. Of the 59 pediatric patients with onychomycosis, 66.1% had toenail onychomycosis with the rest (33.9%) having fingernail onychomycosis. The male-to-female ratio was 1.95:1. Fourteen (23.7%) children had concomitant tinea pedis infection, and tinea pedis or onychomycosis was also found in eight of the parents (13.6%). Distal and lateral subungual onychomycosis was the most common (62.7%) clinical type. In toenails, Trichophyton rubrum was the most common etiological agent (51.3%), followed by Candida albicans (10.2%), C. parapsilosis (5.1%), C. tropicalis (2.6%), and C. guilliermondii (2.6%). In fingernails, C. albicans was the most common isolated pathogen (50.0%), followed by T. rubrum (10.0%), C. parapsilosis (10.0%), and C. glabrata (5.0%).

Conclusion

Because of the increase in pediatric onychomycosis, we suggest the need for a careful mycological examination of children who are diagnosed with onychomycosis.

[Diseases of the nails]

Nail alterations are frequently seen in daily practice, but they are often difficult to interpret. Basic knowledge of the anatomy and biology of the nail facilitates their diagnosis as this frequently allows their development and morphology to be explained. The following short review gives hints at the most important infections, inflammatory nail diseases and tumors.

A preformulation strategy for the selection of penetration enhancers for a transungual formulation

Onychomycosis is associated with the cutaneous fungal infection of the nail and the nail folds (skin surrounding the nail). It is therefore important to target drug delivery into the nail folds along with nail plate and the nail bed. Systematic and strategic selection of the penetration enhancers specific for the skin and the nail is discussed. Twelve penetration enhancers were screened for their ability to improve solubility, in vitro nail penetration, in vitro skin permeation, and in vitro skin penetration of the antifungal drug ciclopirox olamine. In contrast to transdermal drug delivery, the main selection criteria for skin penetration enhancer in topical drug delivery were increased drug accumulation in the epidermis and minimal permeation across the skin. Thiourea improved the solubility and nail penetration of ciclopirox olamine. It also showed enhancement in the transungual diffusion of the drug. Propylene glycol showed a 12-fold increase in solubility and 3-fold increase in epidermal accumulation of ciclopirox olamine, while minimizing the transdermal movement of the drug. Thiourea was the selected nail permeation enhancer and propylene glycol was the selected skin penetration enhancer of ciclopirox olamine. A combination of the selected enhancers was also explored for its effect on drug delivery to the nail and nail folds. The enhancer combination reduced the penetration of ciclopirox in the skin and also the permeation through the nail. The proposed preformulation strategy helps to select appropriate enhancers for optimum topical delivery and paves way towards an efficient topical formulation for passive transungual drug delivery.

Fingernail Onychomycosis Due to Aspergillus niger

Onychomycosis is usually caused by dermatophytes, but some species of nondermatophytic molds and yeasts are also associated with nail invasion. Aspergillus niger is a nondermatophytic mold which exists as an opportunistic filamentous fungus in all environments. Here, we report a case of onychomycosis caused by A. niger in a 66-year-old female. The patient presented with a black discoloration and a milky white base and onycholysis on the proximal portion of the right thumb nail. Direct microscopic examination of scrapings after potassium hydroxide (KOH) preparation revealed dichotomous septate hyphae. Repeated cultures on Sabouraud's dextrose agar (SDA) without cycloheximide produced the same black velvety colonies. No colony growth occurred on SDA with cycloheximide slants. Biseriate phialides covering the entire vesicle with radiate conidial heads were observed on the slide culture. The DNA sequence of the internal transcribed spacer region of the clinical sample was a 100% match to that of A. niger strain ATCC 16888 (GenBank accession number AY373852). A. niger was confirmed by KOH mount, colony identification, light microscopic morphology, and DNA sequence analysis. The patient was treated orally with 250 mg terbinafine daily and topical amorolfine 5% nail lacquer for 3 months. As a result, the patient was completely cured clinically and mycologically.

Natural coniferous resin lacquer in treatment of toenail onychomycosis: an observational study

In in vitro tests, natural coniferous resin from the Norway spruce (Picea abies) is strongly antifungal. In this observational study, we tested the clinical effectiveness of a lacquer composed of spruce resin for topical treatment of onychomycosis. Thirty-seven patients with clinical diagnosis of onychomycosis were enrolled into the study. All patients used topical resin lacquer treatment daily for 9 months. A mycological culture and potassium hydroxide (KOH) stain were done from nail samples in the beginning and in the end of the study. Treatment was considered effective, if a mycological culture was negative and there was an apparent clinical cure. At study entry, 20 patients (20/37; 54%; 95% CI: 38-70) had a positive mycological culture and/or positive KOH stain for dermatophytes. At study end, the result of 13 patients was negative (13/19; 68%; 95% CI: 48-89). In one case (1/14; 7%; 95% CI: 0-21) the mycological culture was initially negative, but it turned positive during the study period. By 14 compliant patients (14/32; 44%; 95% CI: 27-61), resin lacquer treatment was considered clinically effective: complete healing took place in three cases (9%) and partial healing in 11 cases (85%). The results indicate some evidence of clinical efficacy of the natural coniferous resin used for topical treatment of onychomycosis.

[The mould onychomycosis in Morocco: about 150 isolated cases in 20 years]

INTRODUCTION

the involvement of moulds in the fungal ungueal pathology is very variable. In fact a big confusion reigns because of numerous errors in the clinico-biological diagnosis, which could be responsible for therapeutic failure of onychomycosis.

AIMS OF STUDY

The aim of this study was to evaluate the relative frequency of moulds involved in onychomycosis over a period of 20 years.

PATIENTS AND METHODS

This is a retrospective study, conducted at the laboratory of parasitology-mycology of the Ibn Sina hospital over a period of 20 years. The patients were referred by dermatologists or general practitioners for suspected onychomycosis. The samples were studied according to good rules for performing mycological analysis.

RESULTS

One hundred and fifty cases of onychomycosis were diagnosed with mould, with global prevalency of 2.78%. They mainly concern the toes (95%) with a slight female predominance (60%). The total dystrophy of the nail was the predominant clinical representation (88.3%). Moulds isolated were Aspergillus spp. in 53 cases (35.3%) and Fusarium spp. in 45 cases (30%), 19 cases (12.7%) of Scopulariopsis brevicaulis, 17 cases (11.3%) of Penicillium spp., 14 cases (9.3%) of Acremonium spp., one case of Onychocola canadensis (0.7%) and one case of Scytalidium dimitiatum (0.7%).

CONCLUSION

A significant number of onychomycosis remains attributed to moulds, which highlights the contribution of the laboratory, which remains essential for the clinician to confirm the involvement of mould in onychomycosis, which allows taking into support early treatment avoiding the emergence of aesthetic complications.

Onychomycosis caused by Scopulariopsis brevicaulis: report of two cases

Onychomycosis is usually caused by dermatophytes, but some nondermatophytic molds and yeasts are also associated with invasion of nails. Scopulariopsis brevicaulis is a nondermatophytic mold found in soil as a saprophyte. We report two cases of onychomycosis caused by S. brevicaulis in a 48-year-old male and a 79-year-old female. The two patients presented with a typical distal and lateral subungual onychomycosis. Direct microscopic examination of the potassium hydroxide preparation revealed fungal elements. From toenail lesions of the patients, brown colonies with powdery surface, which are a characteristic of S. brevicaulis, were cultured on two Sabouraud's dextrose agar plates. Three cultures taken from nail plates within a 2-week interval yielded similar findings. Numerous branched conidiophores with chains of rough walled, lemon-shaped conidia were observed in slide culture by light microscopy and scanning electron microscopy. The nucleotide sequences of the internal transcribed spacer for the two clinical isolates were identical to that of S. brevicaulis strain WM 04.498. To date, a total of 13 cases of S. brevicaulis onychomycosis including the two present cases have been reported in Korea. Mean age of the patients was 46.1 years, with a higher prevalence in males (69.2%). Toenail involvement was observed in all cases including a case involving both fingernail and toenail. The most frequent clinical presentation was distal and lateral subungual onychomycosis in 12 cases, while one case was proximal subungual onychomycosis.

Onychomycosis due to nondermatophytic molds

BACKGROUND

Although there have been many studies about onychomycosis due to nondermatophytic molds (NDM), few studies about etiologic agents including NDM in onychomycosis have been reported in Korea.

OBJECTIVE

This study investigated onychomycosis due to NDM in the Gyeongju area of Korea.

METHODS

In the 10-year period from 1999~2009, we reviewed 59 patients with onychomycosis due to NDM. The etiologic agents were identified by cultures on Sabouraud's Dextrose agar with and without cycloheximide. In some cases, internal transcribed spacer sequence analysis was done. NDM isolated considered pathogens when the presence of fungal elements was identified by direct microscopy observation and in follow-up cultures yielding the same fungi.

RESULTS

Onychomycosis due to NDM comprised 2.3% of all onychomycosis. Of the 59 patients with onychomycosis due to NDM, 84.7% were toenail onychomycosis and 15.3% were fingernail onychomycosis. The incidence rate was highest in the fifth decade (27.1%). The ratio of male to female patients was 1:1.6. The frequency of associated diseases, in descending order, was hypertension, diabetes mellitus, and cerebral hematoma. Distal and lateral subungual onychomycosis (86.4%) was the most common clinical type of onychomycosis. Aspergillus spp. was the most frequently isolated etiologic agent of onychomycosis due to NDM (83.0%). Other causative agents were Scopulariopsis brevicaulis (10.2%), Acremonium spp. (3.4%), Fusarium solani (1.7%), and Chaetomium globosum (1.7%).

CONCLUSION

Because of the increase in onychomycosis due to NDM, we suggest the need of a careful mycological examination in patients with onychomycosis.

[Onychomycosis: multicentre epidemiological, clinical and mycological study]

BACKGROUND

Onychomycosis accounts for up to 50% of all nail disorders. They can be caused by: yeasts, dermatophytes and non-dermatophyte moulds.

OBJECTIVES AND METHODS

A multicentre study designed to determine the prevalence, mycological test results, aetiological agents, and clinical presentation of onychomycosis was carried out. All fingernail and toenail samples taken during a one year period at 9 diagnostic centres were included.

RESULTS

A total of 5,961 samples were analysed, of which 82.3% were from toenails and 17.7% from fingernails. The mean age of the patients was 49.7 years, and 66% were females. Direct microscopic examination was positive in 61% of the samples. In adults, 61.2% of toenails were positive using potassium hydroxide (KOH), and 43.7% were positive in cultures. The prevailing aetiological agents belong to the dermatophyte group (82.8%), and distal subungual was the most common clinical form. In fingernails, direct examination showed 59.8% positive samples, and cultures were positive in 52.9%. The prevailing agents were yeasts belonging to Candida species, and onycholysis was the most common lesion.

CONCLUSIONS

Direct mycological examinations were positive in 61%, a higher value than that found in other series. Dermatophytes were prevalent in toenails of both sexes, and in finger nails yeast were prevalent in females, and dermatophytes in males. Non-dermatophyte moulds corresponded to 4.8% of toenail and 2.05% of fingernails isolates.

Avaliação clínica e micológica de onicomicose em pacientes brasileiros com HIV/AIDS

INTRODUÇÃO: Onicomicoses são comuns em pacientes imunocomprometidos embora espécies emergentes tenham sido verificadas, modificado o perfil epidemiológico desta micose. Assim, o objetivo desta pesquisa é avaliar o perfil clínico e micológico da onicomicose em pacientes com infecção pelo HIV/AIDS. MÉTODOS: Amostras clínicas foram coletadas, processados para exame direto e a cultura mantida a temperatura de 30°C e 37ºC durante 15 dias. RESULTADOS: Dos 100 pacientes, 32 apresentavam onicomicose. Os agentes isolados foram Candida albicans, C. parapsilosis, C. tropicalis, C. guilliermondii, Trichophyton rubrum, T. mentagrophytes, Fusarium solani, Scytalidium hialinum, S. japonicum, Aspergillus niger, Cylindrocarpon destructans e Phialophora reptans. CONCLUSÕES: Onicomicoses em HIV/AIDS apresentam variadas manifestações clínicas e podem ser causadas por fungos emergentes. As peculiaridades apresentadas pelos diferentes agentes de origem fúngica justificam a necessidade de identificação ao nível da espécie, com a finalidade de orientar uma melhor abordagem terapêutica e minimizar a exposição desses pacientes a condições de risco de uma infecção disseminada.

A study on the etiological agent and clinico-mycological correlation of fingernail onychomycosis in eastern India

Background:

Onychomycosis manifests itself in various forms, notably onychodystrophy, onycholysis, subungual hyperkeratosis, or nail-plate discoloration. Not necessarily nail changes mentioned here should always be of fungal origin.

Objective:

The present study is planned to get an idea about etiological agent and clinical correlation in fingernail onychomycosis.

Materials and Methods:

Nail-clipping and subungual debris of patients with above mentioned nail changes were subjected to KOH preparation. Culture was done on SDA and SDCCA media. Species identification was done by colony character, pigment production, LCB staining, and some special tests like germ tube test, etc.

Results:

Out of 85 cases, 44 cases showed the growth of fungus, amounting to 51.76% positivity. Among those 44 cases, the infective fungal agents were predominantly dermatophytes (50%), and the rest were due to yeasts (27.27%) and moulds (22.72%). Among the different species, Trichophyton rubrum (29.54%) accounted for the majority of dermatophytes; Candida albicans (11.78%) was the predominant yeast; and Aspergillus niger (18.18%) the commonest mold. No significant association could be established between the different fungal species and various clinical manifestations. Positive results were found more with fungal culture (95.45%) than KOH preparation (63.64%).

Conclusion:

The results show that nail changes are not always a reliable marker for predicting the causative organism, and relying only on the clinical manifestation (i.e., pattern of nail changes) in the diagnosis of onychomycosis is often misleading. The present study highlights the need for microbiological confirmation in case of onychomycosis.

Other fungi causing onychomycosis

Nondermatophyte onychomycosis account for 2% to 12% of all nail fungal infections and can be caused by a wide range of fungi, mainly Scopulariopsis brevicaulis, Aspergillus versicolor, A. flavus, A. niger, A. fumigatus, Fusarium solani, F. oxysporum and Scytalidium spp. Among the predisposing factors are footwear, hyperhidrosis, local trauma, peripheral circulatory disease, and immunosuppression. These nondermatophyte fungi lack the keratinolytic capacity of dermatophytes, but they still can infect alone or in combination with the latter. Because most are considered laboratory contaminants, special criteria have been created for the correct diagnosis of nondermatophyte onychomycosis. The etiologic agent does not determine the clinical pattern of nail invasion, but superficial onychomycosis is frequently observed; leukonychia and melanonychia can also be clinical manifestations.

Intermittent versus continuous terbinafine in the treatment of toenail onychomycosis: A randomized, double‐blind comparison

BACKGROUND

Terbinafine is an established drug for the treatment of toenail onychomycosis. Minimizing the total dose of terbinafine and giving it intermittently could improve tolerability as well as compliance, provided efficacy is not compromised.

OBJECTIVE

Two identical trials were conducted to compare the efficacy, safety and tolerability of the current standard regimen of terbinafine 250 mg daily with a new formulation of terbinafine given intermittently for three cycles of 2 weeks of treatment (350 mg daily) followed by 2 weeks off treatment.

METHODS

A total of 2005 patients with a clinical diagnosis of subungual onychomycosis of the large toenail confirmed by microscopy and culture for a dermatophyte were recruited into the two trials and treated for 12 weeks.

RESULTS

Patients with onychomycosis of prolonged duration (mean 9 years) and a median nail involvement of 63% with or without spikes, lateral involvement and white superficial onychomycosis (WSO) were included in the trial. The studies found a significant difference (p<0.05) in favour of standard daily dosing with terbinafine. Response rates for the primary variable complete cure (mycological and clinical cure) were lower with the new formulation in both Trial I (-5.8%; 95% CI -11.8, 0.07) and Trial II (difference -5.9%; 95% CI -12, 0.1). Both treatments were equally well tolerated, with approximately 11% of patients in both groups reporting at least one treatment-related adverse event.

CONCLUSIONS

Pulsed dosing with terbinafine did not provide any clear safety advantages and was significantly less effective. Consequently, continuous treatment with terbinafine tablets remains the optimal therapy for onychomycosis.

Candidal onychomycosis: a mini-review

Onychomycosis is a common fungal infection affecting nails. The primary cause for onychomycosis is dermatophytes, while Candida species have emerged as second-line pathogens. Onychomycosis due to Candida (candidal onychomycosis) is increasingly found in individuals having defective immunity consequential to aging, diabetes mellitus, vascular diseases, HIV infection and drug therapies such as immunosuppressives and broad-spectrum antibiotics. Breached local immunity at the nail complex due to trauma, chronic exposure to moisture and chemicals including smoke, detergents, soap, etc., also contribute to candidal onychomycosis. Adhesion, filamentation, secretion of extracellular enzymes and the development of antifungal resistance are some of the virulence mechanisms of Candida species associated with onychomycosis. Diagnosis of onychomycosis depends on history and clinical examination, direct microscopic investigation, mycological culture and histopathology. Restoration of immune defenses, elimination of fungi using appropriate drug therapy and improvement of nail hygiene with the removal of predisposing factors are key aspects in the management of candidal onychomycosis.

Onychomycosis caused by Fusarium sp in Sri Lanka: prevalence, clinical features and response to itraconazole pulse therapy in six cases

OBJECTIVES

The aims of our study were to ascertain the proportion of Fusarium onychomycosis among patients with suspected onychomycosis, to record clinical features and to assess the efficacy of itraconazole pulse therapy in treatment.

METHODS

Six patients with positive isolates of Fusarium sp were treated in an open, prospective manner with itraconazole: two pulses for fingernails and three pulses for toenails. Significant growth of Fusarium sp was considered when both microscopy of direct mounts in KOH and culture were positive for mold. Efficacy parameters were mycological cure and clinical cure. Mycological cure was negative direct microscopy (KOH) and culture. Clinical cure was complete absence of signs of onychomycosis.

RESULTS

Prevalence of Fusarium onychomycosis was 6.25% (8/128). Three women and three men were studied. All had bilateral big toenails involved which were of the distal and lateral onychomycosis. Three of them had associated fingernail onychomycosis with periungual inflammation. All our patients were immunocompetent. At month 12 from the start of treatment, mycological cure was 100% while only three out of five patients showed normal nail growth and clinical cure. There were no significant clinical or laboratory adverse effects.

CONCLUSIONS

Our data reconfirmed that Fusarium nail infections are difficult to eradicate. Since the therapeutic reservoir in toenails is 11 months, these patients should be followed up for a total of 12 months before coming to the final conclusion.