Molecular Detection of Dermatophytes and Nondermatophytes in Onychomycosis in Antalya, Turkey.

BACKGROUND: Onychomycosis is a chronic nail infection, and dermatophytes, yeasts, and nondermatophytic molds may be the causative agents. This study aimed to determine the etiological agents of onychomycosis by using conventional and molecular methods. METHODS: Between June 2020 and July 2021, 37 patients with a presumptive diagnosis of onychomycosis and mycological evidence (culture and/or EUROArray Dermatomycosis assay) were included in the study. Organisms detected in cultured nail specimens were identified by combined phenotypic characteristics and by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). An EUROarray Dermatomycosis assay was used for molecular detection of fungal pathogens. RESULTS: The EUROArray Dermatomycosis assay was positive for a single fungal target in 23 samples, and 14 samples were positive by culture. The most common pathogen was Trichophyton rubrum in both methods. Coinfection was detected in 14 samples by using molecular methods, and Trichophyton rubrum and Fusarium solani (9 samples) were the most common pathogens detected together. Trichophyton spp., nondermatophyte molds, and Candida spp. were detected in 33 (89.2%), 16 (43.2%), and 6 (16.2%) samples, respectively, when the two methods were evaluated together. CONCLUSIONS: Our results revealed that fungal culture allows the diagnosis of onychomycosis, but it is not as sensitive as the EUROArray Dermatomycosis test, especially in patients receiving antifungal therapy.

Onychoscopic characteristics of Trichophyton rubrum and Trichophyton interdigitalis fungal infections: A multicentric study.

BACKGROUND: Trichophyton rubrum and Trichophyton mentagrophytes variant interdigitalis are the most frequent etiologic agents of onychomycosis. Diagnosis of certainty requires mycological examination, which often results unfeasible. OBJECTIVES: The aim of our study is to describe pathogen specific dermoscopic features, allowing a differential diagnosis without the need for cultural examination, in order to prescribe the most appropriate treatment anyway. PATIENTS AND METHODS: We conducted an observational retrospective study on 54 patients with a culture proven diagnosis of distal subungual onychomycosis of the toenail, caused by Trichophyton rubrum or Trichophyton mentagrophytes variant interdigitalis. Using a videodermatoscope we collected data on nail colour (white, yellow, orange, brown, dark) and on dermoscopic patterns (aurora, spikes, jagged, ruin, linear edge, dots, striae). RESULTS: Fifty-four patients, with a total of 72 nails, were eligible for this study. Analysing the association between discoloration of the nail plate and type of infection (T. rubrum or T. interdigitalis), no correlation turned out to be statistically significant. Instead, significant associations between spikes and T. rubrum infection and striae and infection from T. interdigitalis were identified. Finally, a 100% specificity was identified for white colour and ruin pattern for T. rubrum infection, and brown colour, jagged border and aurora pattern for T. interdigitalis. CONCLUSIONS: Trying to find relationships between specific pathogens and dermoscopic patterns, we found out an association between spikes and striae and T. rubrum and T. interdigitalis respectively. Further larger studies are however necessary to evaluate our preliminary findings.

Inter-observer reliability of the Onychomycosis Severity Index depending on clinical experience: A review of 50 cases.

BACKGROUND: Onychomycosis (ONM) is the most prevalent nail unit pathology, and its severity and monitoring are often based on the visual judgement of clinicians. OBJECTIVE: The objective of this study is to assess the reliability of the Onychomycosis Severity Index (OSI) classification when utilized by three clinicians with varying levels of clinical experience: an experienced podiatrist (with 5 years of experience), a moderately experienced podiatrist (with 2 years of experience) and an inexperienced podiatrist (a recent graduate familiar with the OSI classification but lacking clinical experience). Additionally, we compared the severity assessments made through visual inspection with those determined using the OSI by different clinicians. METHODS: We evaluated reliability using the intraclass correlation index (ICC), analysing 50 images of ONM. RESULTS: The OSI demonstrated a very high level of reliability (ICC: 0.889) across clinicians, irrespective of their experience levels. Conversely, a statistically significant increase in severity was observed when comparing visual assessments with the OSI (p < .001) for ONM severity evaluation. CONCLUSION: The OSI proves to be a reproducible classification system, regardless of the clinical experience of the practitioner employing it.

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

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

Diagnostic Accuracy of Dermatoscopy Versus Microbiological Culture and Polymerase Chain Reaction in the Diagnosis of Onychomycosis: A Cross-Sectional Study.

BACKGROUND: Several clinical signs in dermatoscopy are very characteristic of onychomycosis and can be a quick complement for the diagnosis of onychomycosis. OBJECTIVES: The aim of this study was to evaluate the diagnostic accuracy of dermatoscopy compared to microbiological culture and polymerase chain reaction (PCR), as well as the clinical signs associated with onychomycosis. METHODS: The clinical signs of 125 patients were assessed cross-sectionally using dermatoscopy, and a positive or negative result was assigned. A sample was then taken for PCR and microbiological culture. RESULTS: Of the 125 patients, 69.6% (87/125) had positive results when both laboratory tests were combined. When they were not combined, the prevalence was lower at 48% (60/125) with PCR and at 43.2% (54/125) with culture. Furthermore, 76.8% (96/125) were classified as positive with dermatoscopy with a sensitivity of 1, a specificity of 0.76, positive predictive value of 0.91 and negative predictive value of 1 (with 95% confidence intervals). Of the 96 dermatoscopy-positive samples, 36 were negative with PCR (p < 0.001), 42 were negative with culture (p < 0.001) and nine were negative when both tests were combined (p < 0.001). Clinical signs that were significantly associated with the presence of onychomycosis were subungual hyperkeratosis (dermatoscopy: p = 0.004, odds ratio (OR) = 2.438; PCR + microbiological culture: p = 0.004, OR = 3.221), subungual detritus (p = 0.033, OR = 3.01, only with dermatoscopy) and dermatophytoma (dermatoscopy: p = 0.049, OR = 3.02; PCR + microbiological culture: p = 0.022, OR = 2.40). CONCLUSIONS: The results suggest that dermatoscopy is a good tool for the diagnosis of onychomycosis but should be used as a complementary test or for screening patients to be sampled for laboratory testing. The combination of the three tests can lead to a reduction of false-positive and false-negative clinical and laboratory results. This allows for early diagnosis and specific treatment based on test results.

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

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

Nail psoriasis in China: A prospective multicentre study.

BACKGROUND: Data on nail psoriasis (PsO) in China are scarce. OBJECTIVES: To provide nail PsO-related data regarding epidemiologic characteristics, manifestations, fungal infections, arthritic complaints and treatments that may facilitate improved patient management globally. METHODS: From August 2021 to August 2022, patients with nail PsO were enrolled in a prospective multicentre observational study at 25 hospitals in China. We collected and analysed data concerning nail PsO demography, clinical signs, fungal detection, arthritic symptoms and treatment. RESULTS: A total of 817 patients with nail PsO were involved, with a mean body mass index of 24.13 ± 2.93. In addition, 71.41% of the patients were male. The Nail PsO Severity Index score was weakly positively correlated with body surface area. The percentage of nail involvement was 95.29% for fingernails and 57.18% for toenails, with pitting (67.11%) and subungual hyperkeratosis (60.40%) being the most prevalent manifestations, respectively. Toenails showed a significantly higher frequency of nailfold scales, subungual hyperkeratosis and nail plate crumbling and a lower frequency of splinter haemorrhages, pitting and erythema of the lunula. A total of 13.26% of the PsO patients had onychomycosis, and 77.08% were observed in the toenails. Articular symptoms were reported by 12.17% of the patients, with the peripheral type being predominant. Significant associations between articular symptoms and nailfold swelling, subungual hyperkeratosis, nailfold scales, onycholysis and longitudinal ridges were found. Only 2.30% (20 out of 871) of patients with nail PsO received treatment. The most frequently employed therapy for cutaneous PsO with nail involvement was biologic therapy (n = 366). CONCLUSIONS: PsO showed distinct manifestations in the toenails and fingernails. Additionally, toenail PsO combined with onychomycosis requires special attention. Articular symptoms in psoriatic patients are associated with specific nail changes. It is important to research and advocate for more potent treatments for nail PsO.

Number of Affected Nails Is the Primary Determinant of Efinaconazole 10% Solution Usage for Onychomycosis.

Good adherence to treatment is necessary for the successful treatment of onychomycosis and requires that an appropriate amount of medication be prescribed. Most prescriptions for efinaconazole 10% solution, a topical azole antifungal, are for 4 mL per month but there are no data on patient factors or disease characteristics that impact how much medication is needed. Data from two phase 3 studies of efinaconazole 10% solution for the treatment of toenail onychomycosis were pooled and analyzed to determine monthly medication usage based on the number of affected toenails, percent involvement of the target toenail, body mass index (BMI), and sex. Participants with two or more affected nails required, on average, >4 mL of efinaconazole per month, with increasing amounts needed based on the number of nails with onychomycosis (mean: 4.39 mL for 2 nails; 6.36 mL for 6 nails). In contrast, usage was not greatly impacted by target toenail involvement, BMI, or sex. Together, these data indicate that the number of affected nails should be the major consideration when determining the monthly efinaconazole quantity to prescribe. J Drugs Dermatol. 2024;23(2):110-112.    doi:10.36849/JDD.7676.

Line-field confocal optical coherence tomography, a novel non-invasive tool for the diagnosis of onychomycosis.

BACKGROUND AND OBJECTIVES: Onychomycosis is common and important to distinguish from other nail diseases. Rapid and accurate diagnosis is necessary for optimal patient treatment and outcome. Non-invasive diagnostic tools have increasing potential for nail diseases including onychomycosis. This study evaluated line-field confocal optical coherence tomography (LC-OCT) as a rapid non-invasive tool for diagnosing onychomycosis as compared to confocal laser scanning microscopy (CLSM), optical coherence tomography (OCT), and conventional methods. PATIENTS AND METHODS: In this prospective study 86 patients with clinically suspected onychomycosis and 14 controls were examined using LC-OCT, OCT, and CLSM. KOH-preparation, fungal culture, PCR, and histopathology were used as comparative conventional methods. RESULTS: LC-OCT had the highest sensitivity and negative predictive value of all methods used, closely followed by PCR and OCT. Specificity and positive predictive value of LC-OCT were as high as with CLSM, while OCT scored much lower. The gold standard technique, fungal culture, showed the lowest sensitivity and negative predictive value. Only PCR and culture allowed species differentiation. CONCLUSIONS: LC-OCT enables quick and non-invasive detection of onychomycosis, with advantages over CLSM and OCT, and similar diagnostic accuracy to PCR but lacking species differentiation. For accurate nail examination, LC-OCT requires well-trained and experienced operators.

Is Raman Spectroscopy of Fingernails a Promising Tool for Diagnosing Systemic and Dermatological Diseases in Adult and Pediatric Populations?

Background: Raman spectroscopy is a well-known tool used in criminology, molecular biology, and histology. It is also applied to diagnose bone mineral disorders by taking advantage of the similarity of the structure of keratin and bone collagen. Raman spectroscopy can also be used in dermatology and diabetology. The purpose of the present review is to critically evaluate the available research about the use of Raman spectroscopy in the mentioned areas of medicine. Methodology: PubMed was searched for peer-reviewed articles on the subject of use of Raman spectroscopy in bone mineral disorders, dermatology, and diabetes mellitus. Results: Nail keratin and bone collagen are related structural proteins that require disulfide bond for structural stability. Therefore, Raman spectroscopy of keratin may have potential as a diagnostic tool for screening bone quality and distinguishing patients at risk of fracture for reasons different from low bone mineral density (BMD) in the adult women population. Raman spectroscopy can also investigate the changes in keratin's structure in nails affected by onychomycosis and distinguish between healthy and onychomycosis nail samples. It could also reduce the need for nail biopsy by distinguishing between dermatophytic and non-dermatophytic agents of onychomycosis. Additionally, Raman spectroscopy could expedite the diagnostic process in psoriasis (by assessing the secondary structure of keratin) and in diabetes mellitus (by examining the protein glycation level). Conclusions: In adult populations, Raman spectroscopy is a promising and safe method for assessing the structure of fingernails. However, data are scarce in the pediatric population; therefore, more studies are required in children.

Clinical evaluation of a dermatophyte RT-PCR assay and its impact on the turn-around-time: A prospective study.

Onychomycosis is an important public health problem whose prevalence continues to grow and impact public health at several levels. Nevertheless, today the main diagnostic methods used in routine practice have many drawbacks. The aim of this study was to evaluate, for the first time, the clinical performance of a new multiplex polymerase chain reaction (PCR) (Novaplex®) in the identification of the causative agent on nail samples, and its impact on the turnaround time, compared to our traditional laboratory methods. From June 2022 to December 2022, all nail samples sent to our laboratory for suspected onychomycosis were included in this prospective study. We collected for each sample the results obtained with the Novaplex® PCR method and with the traditional direct microscopy examination and culture. Each discordant result was checked using a third method, which is another PCR method (DermaGenius® kit) as a resolver. For culture-positive samples, a turnaround time was calculated and compared to the one obtained with the Novaplex® method. A total of 131 samples were included. Among them, 5 were positive (3.8%) on direct microscopy, 33 were positive (25.2%) after culture, and 98 were negative (74.8%). All positive (n = 33) and negative (n = 69) cultures were also positive/negative with the Novaplex® PCR. Twenty-nine samples were positive with the Novaplex® method but negative with culture (discordant results). The percentage agreement between the culture and the Novaplex® methods was 77.9% (102 out of 131). While tested with the resolver (DermaGenius® PCR), 28 out of 29 discordant results were similarly found positive. The percentage agreement between the two PCR methods (Novaplex® and DermaGenius®) was 96.6%. The Novaplex® PCR method evaluated proved to be very reliable and allowed the direct identification of 62 out of 131 positive samples (47.3%) with the following distribution: 79.0% of Trichophyton rubrum complex, 11.3% of Trichophyton mentagrophytes complex, 6.5% of both Trichophyton rubrum complex and Trichophyton mentagrophytes complex, and 3.2% of Candida albicans. The median time [± 95% CI] for positive culture (between incubation and validation of the final identification) was 15 [12-23] days, while the turnaround time for the Novaplex® method adapted to our clinical laboratory routine is ≤7 days. Laboratory confirmation of onychomycosis is crucial and should always be obtained before starting treatment. The evaluated PCR method offered a rapid, reliable, robust, and inexpensive method of identification of the causative agent compared to traditional methods.

The aim of this study was to evaluate the clinical performance of a multiplex PCR in the identification of the causative agent of onychomycosis on nail samples, and its impact on the turnaround time, compared to our traditional laboratory methods. This new method is rapid, reliable, robust, and inexpensive.

Onychomycosis in immunocompromised population: Phenotypic and molecular identification.

Onychomycosis is common among immunosuppressed individuals. Renal transplant recipients (RTR) and lupus nephritis (LN) patients are submitted to corticosteroid and other immunosuppressive therapy; and diabetes mellitus (DM) patients are intrinsically immunocompromised. OBJECTIVES: The aim of this study was to characterise and identify fungal infections on the nails (feet and hands) in immunocompromised patients. METHODS: The clinical material, nail scales (foot and/or hand), was collected from 47 RTR, 66 LN, 67 DM, and 78 immunocompetent individuals (control group). Phenotypic and molecular analyses were performed. RESULTS: A total of 258 patients were examined. There was a female predominance, except in the RTR. The average age was 52 years old. Lateral distal subungual onychomycosis (OSDL) (75.2%), mainly affecting the hallux nail, was frequent. The predominance of dermatophyte on toenails and Candida species on fingernails was statistically significant. A higher frequency of fingernail involvement in LN and DM, and for LN, the difference was significant (p = .0456). Infections by Candida spp. were more frequent in DM. Using molecular methods, 87.2% of diagnoses were confirmed, identifying fungal agents at the species level. Dermatophytes, Trichophyton rubrum and Trichophyton interdigitale and the species of Candida, C. parapsilosis and C. albicans, were the most frequent fungal agents. CONCLUSIONS: Molecular techniques (sequencing of ITS regions of rDNA) offer greater accuracy, although there is no difference, regarding the detection. Clinical presentation and fungal species may differ somewhat from the general population. Immunosuppression did not increase fungal detection positivity.

Children onychomycosis, a neglected dermatophytosis: A retrospective study of epidemiology and treatment.

BACKGROUND: Onychomycosis was an ignored disease in children, and the prevalence was still unknown worldwide. OBJECTIVES: This study was conducted to investigate the prevalence and treatment regimens of onychomycosis in children younger than 18 years old. METHODS: We systemically reviewed all publications by searching the key terms to reveal the onychomycosis in children from 1990 to 2022. RESULTS: A total of 44 articles including 2,382 children with onychomycosis were enrolled in this study. The male to female ratio was 1.29:1. The youngest child was 35 days old and the average age was 9.8 years old. The duration of disease usually ranged from 7 days to 4 years. Onychomycosis in children was more prevalent in toenails compared to fingernails (77.6% vs. 18.4%), and 4% patients had both. A total of 527 children (22.12%) had concomitant tinea pedis infection, and in 267 patients (11.21%), their family members had onychomycosis or tinea pedis. The most common clinical type of onychomycosis was DLSO (67.74%) and the predominant isolates were T. rubrum (66.13%), followed by C. albicans (9.08%) and T. mentagrophytes complex (5.34%). There were 419 children (74.03%) receiving systematic treatment only, 74 patients (13.07%) receiving topical treatment only, and 73 patients (12.90%) receiving both systematic and topical treatment. Twelve patients (2.12%) had mild drug-related side effects. During the follow-up, 71.25% children were cured, 17.50% symptoms improved and 4.17% failed. CONCLUSIONS: Onychomycosis was underestimated in children and the diagnosis of onychomycosis should be properly considered in children with nail disorders. For mild patients, topical treatment can be a good choice, and oral antifungal drugs could be added to severe individuals under monitoring.

Onychomycosis associated with diabetic foot syndrome: A systematic review.

BACKGROUND: A systematic review was conducted to investigate the prevalence of onychomycosis in patients with diabetes. The association of onychomycosis with risk factors in patients with diabetic foot syndrome was also examined. METHODS: The recommendations in the preferred reporting items for systematic reviews and meta-analysis (PRISMA) checklist were applied, and the included studies were assessed using the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) method. Searches were conducted in October 2022 using PubMed (Medline) and Scopus for clinical studies, clinical trials, comparative studies, observational studies, and randomised clinical trials or controlled clinical trials addressing the prevalence and consequences of onychomycosis in patients with diabetes, diagnoses or treatments. Two authors performed the study selection and data extraction, and any discrepancies between the two reviewers were resolved through discussion with a third reviewer. RESULTS: The systematic review included ten studies that met the inclusion criteria, and these studies enrolled 5664 patients with diabetes. Among these patients, 29.18% had onychomycosis that was mainly caused by Trichophyton rubrum. A significant association was found between the occurrence of onychomycosis and the presence of diabetic neuropathy (p = .012) and elevated glycosylated haemoglobin values (p = .039). There was no significant association between onychomycosis and ulceration (p = .185). Eight studies had a grade 4 level of evidence and a grade C recommendation, and one study had a grade 1b level of evidence and a grade A recommendation. CONCLUSION: The information described in the literature is insufficient and heterogeneous regarding the association of risk factors and ulceration in patients with diabetic foot compared with developing onychomycosis. There is also a need to implement onychomycosis diagnostic testing instead of relying only on a clinical diagnosis. Additional prospective, randomised, comparative studies are needed to increase the quality of studies in the literature.

Microbiological culture combined with PCR for the diagnosis of onychomycosis: Descriptive analysis of 121 patients.

BACKGROUND: Onychomycosis is the most common nail pathology, involving various pathogens such as dermatophytes, moulds and yeasts. OBJECTIVE: The objective of this study was to observe the prevalence of onychomycosis, analyse the most appropriate diagnostic test, and assess the distribution of pathogens based on age, sex, quarter of the year, duration of symptoms and previous treatment. METHODS: Retrospectively, mycological culture and PCR data and results were collected from 121 patients. RESULTS: Of the 121 samples, 57% (69/121) tested positive when both microbiological study techniques were combined. The prevalence of onychomycosis was higher when PCR was performed (52.1%) compared to microbiological culture (33.1%). Among the 81 samples negative by microbiological culture, 31 were positive by PCR. Similarly, of the 58 samples negative by PCR, eight were positive by microbiological culture. Diagnostic accuracy data (with 95% confidence intervals) for PCR, using microbiological culture as the gold standard, were as follows: sensitivity of 0.8, specificity of 0.62, positive predictive value of 0.51 and negative predictive value of 0.86. The most frequently identified pathogen was Trichophyton rubrum, and the hallux nail plate was the most commonly affected location. However, no statistically significant associations were found between sex, age, quarter of the year and affected area with culture and PCR results. CONCLUSION: Combining microbiological culture and PCR can increase the detection rate of onychomycosis and help avoid false-negative results.

Combatting antifungal resistance: Paradigm shift in the diagnosis and management of onychomycosis and dermatomycosis.

Antifungal resistance has become prevalent worldwide. Understanding the factors involved in spread of resistance allows the formulation of strategies to slow resistance development and likewise identify solutions for the treatment of highly recalcitrant fungal infections. To investigate the recent explosion of resistant strains, a literature review was performed focusing on four main areas: mechanisms of resistance to antifungal agents, diagnosis of superficial fungal infections, management, and stewardship. The use of traditional diagnostic tools such as culture, KOH analysis and minimum inhibitory concentration values on treatment were investigated and compared to the newer techniques such as molecular methods including whole genome sequencing, and polymerase chain reaction. The management of terbinafine-resistant strains is discussed. We have emphasized the need for antifungal stewardship including increasing surveillance for resistant infection.

Comparing the Efficacy for Pulse Versus Continuous Dose Terbinafine Therapy in Patients With Onychomycosis.

Recently, treatment outcomes in patients with toenail onychomycosis have improved considerably due to more effective oral antifungal medications such as terbinafine and itraconazole. These medications can either be used continuously for several weeks at a lower dose or intermittently (pulsed) at a higher dose. Previous literature comparing pulse and continuous therapy has generated mixed results.  Our study aims to compare the efficacy, in terms of clinical cure rate, of continuous vs pulse dose terbinafine regimens for toenail onychomycosis. Sixty patients with onychomycosis of Fitzpatrick skin types IV to VI, between 15 and 65 years of age, were divided into a continuous treatment group receiving 250 mg terbinafine once daily for 12 weeks and a pulse treatment group receiving 250 mg twice daily terbinafine for 1 week repeated every 4 weeks for 12 weeks. Each patient was followed up at weeks 4, 8, and 12.  Efficacy of the continuous treatment group was significantly greater at 76.67% compared with 26.67% in the pulse treatment group. Thus, we conclude that the clinical cure rate of a continuous dose regimen of terbinafine is a superior treatment option for toenail onychomycosis. However, we also suggest further studies including combinations of multiple agents and hybrid regimen models for the optimal onychomycosis treatment.   J Drugs Dermatol. 2023;22(10):     doi:10.36849/JDD.7323R1.

Onychomycosis Treatment Prescribed at Only Twenty Percent of Visits: A Cross-Sectional Analysis of the National Ambulatory Medical Care Survey 2007 to 2016.

BACKGROUND: Onychomycosis represents the highest proportion of nail disorders seen in clinical practice. Onychomycosis management may differ amongst specialties, with impact on patient outcomes and quality of life (QoL). OBJECTIVE: We aimed to characterize onychomycosis treatment across specialties, accounting for patient demographics, to assess for potential onychomycosis practice gaps. MATERIALS/METHODS: We conducted a population based cross-sectional analysis using the National Ambulatory Medical Care Survey (NAMCS) 2007 to 2016 (the most recent years available). RESULTS: Overall, 71.6% of onychomycosis visits were with general practitioners (GPs), 25.8% with dermatologists, and 2.58% with pediatricians. No onychomycosis treatment was prescribed at 82.0% of dermatology visits and 78.9% of GP visits. Dermatologists (Odds Ratio (OR):2.27 [95% Confidence Interval (CI):[2.14-2.41]; P<0.0001) and GPs (OR:2.32 [2.21-2.44]; P<0.0001) were more likely than pediatricians to prescribe treatment vs no treatment. Dermatologists were more likely than GPs to prescribe both no treatment vs treatment and topical vs oral antifungals (OR:1.33 [1.16-1.52]; P<0.0001 and OR:4.20 [3.80-4.65]; P<0.0001), respectively. DISCUSSION: Our study showed that there is a low treatment rate for onychomycosis, with treatment prescribed at only 20% of visits. Untreated onychomycosis might result in secondary infection, pain, and negative QoL impact.1 Although dermatologists are specialists in nail disease management, they saw only about 25% of onychomycosis visits. Future efforts should be directed towards promoting onychomycosis therapy, and educating both patients and referring physicians that dermatologists are primary resources for nail disorder treatment.J Drugs Dermatol. 2023;22(10):1040-1045 doi:10.36849/JDD.6770.

The Role of Histological Examination of Nail Clipping in the Diagnosis of Onychomycosis.

BACKGROUND: Diagnosis of onychomycosis is based on potassium hydroxide (KOH), direct smear, culture, and polymerase chain reaction. Nail clippings are rarely used as a diagnostic tool. OBJECTIVES: To evaluate nail clippings for the diagnosis of onychomycosis and to compare it to KOH smears. METHODS: Nail clipping specimens of 39 patients were collected: 34 with onychomycosis proved by positive culture and 5 from normal nails. The specimens were submitted to histological processing and then stained with periodic acid-Schiff (PAS) and Grocott-Gomori's methenamine silver (GMS) stains. For each nail, KOH smear was also performed. Two pathologists who had no information on the KOH smear and the culture results evaluated the nail clipping histology for the presence of fungal element. Their assessment was compared to the KOH smear and culture results. RESULTS: Of the 34 specimens that had positive culture, 25 were dermatophytes, 5 were molds, and 4 were candida. Clipping specimens were positive in 30 cases (88%): 23/25 dermatophyte, 4/5 molds, and 3/4 candida. Pathologists were able to classify the pathogens into dermatophytes and non-dermatophytes based on the morphology. PAS stain results were the same as GMS in evaluation of the nail specimen. KOH smear was positive in 29 nails (85%): 20/25 dermatophytes, all 5 molds, and 4 candida. In all five nails where the culture was negative, both clipping and KOH smear did not show fungal elements. CONCLUSIONS: Nail clippings can serve as a rapid, inexpensive, and reliable method for evaluation of onychomycosis, comparable to KOH smear, with the advantage of pathogen group identification.

S1 Guideline onychomycosis.

Onychomycosis is a fungal infection of the fingernails and toenails. In Europe, tinea unguium is mainly caused by dermatophytes. The diagnostic workup comprises microscopic examination, culture and/or molecular testing (nail scrapings). Local treatment with antifungal nail polish is recommended for mild or moderate nail infections. In case of moderate to severe onychomycosis, oral treatment is recommended (in the absence of contraindications). Treatment should consist of topical and systemic agents. The aim of this update of the German S1 guideline is to simplify the selection and implementation of appropriate diagnostics and treatment. The guideline was based on current international guidelines and the results of a literature review conducted by the experts of the guideline committee. This multidisciplinary committee consisted of representatives from the German Society of Dermatology (DDG), the German-Speaking Mycological Society (DMykG), the Association of German Dermatologists (BVDD), the German Society for Hygiene and Microbiology (DGHM), the German Society of Pediatric and Adolescent Medicine (DGKJ), the Working Group for Pediatric Dermatology (APD) and the German Society for Pediatric Infectious Diseases (DGPI). The Division of Evidence-based Medicine (dEBM) provided methodological assistance. The guideline was approved by the participating medical societies following a comprehensive internal and external review.