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.

Fungal Skin Disease Classification Using the Convolutional Neural Network.

Skin is the outer cover of our body, which protects vital organs from harm. This important body part is often affected by a series of infections caused by fungus, bacteria, viruses, allergies, and dust. Millions of people suffer from skin diseases. It is one of the common causes of infection in sub-Saharan Africa. Skin disease can also be the cause of stigma and discrimination. Early and accurate diagnosis of skin disease can be vital for effective treatment. Laser and photonics-based technologies are used for the diagnosis of skin disease. These technologies are expensive and not affordable, especially for resource-limited countries like Ethiopia. Hence, image-based methods can be effective in reducing cost and time. There are previous studies on image-based diagnosis for skin disease. However, there are few scientific studies on tinea pedis and tinea corporis. In this study, the convolution neural network (CNN) has been used to classify fungal skin disease. The classification was carried out on the four most common fungal skin diseases: tinea pedis, tinea capitis, tinea corporis, and tinea unguium. The dataset consisted of a total of 407 fungal skin lesions collected from Dr. Gerbi Medium Clinic, Jimma, Ethiopia. Normalization of image size, conversion of RGB to grayscale, and balancing the intensity of the image have been carried out. Images were normalized to three sizes: 120 × 120, 150 × 150, and 224 × 224. Then, augmentation was applied. The developed model classified the four common fungal skin diseases with 93.3% accuracy. Comparisons were made with similar CNN architectures: MobileNetV2 and ResNet 50, and the proposed model was superior to both. This study may be an important addition to the very limited work on the detection of fungal skin disease. It can be used to build an automated image-based screening system for dermatology at an initial stage.

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.

Onychomatricoma on the fourth toenail: A rare tumor in a rare localization.

Onychomatricoma is a rare benign tumor of the nail matrix, characterized by finger-like projections that invade the nail plate. The fingernails of Caucasian women are most commonly affected. Because this tumor can easily mimic other more prevalent ungual diseases, it is crucial to be acquainted with its characteristic clinical and histopathologic features. The authors present a case of a 40-year-old man with an onychomatrichoma in the fourth left toenail, which was initially misdiagnosed and treated as onychomycosis.

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

Background: Dermatophytoma is a recalcitrant condition of onychomycosis (OM). It presents as a white- or yellow-colored fungal mass that appears linear/triangular or round on a nail plate. Traumatic onychodystrophy (TO) can present with dermatophytoma-like lesions. Typically, OM and TO are not clinically distinguishable. Mycological testing is the gold standard for differentiating these disorders. Objectives: This study is aimed at differentiating between the clinical and dermoscopic factors related to dermatophytoma onychomycosis (DP-OM) and dermatophytoma-like traumatic onychodystrophy (DP-TO). Methods: A retrospective study was conducted of patients with dermatophytoma-like nail lesions who visited the Siriraj Nail Clinic between January 2010 and July 2020. The diagnosis of DP-OM was made by direct microscopy, fungal cultures, and histopathology of nail clippings. Results: A total of 36 nails were included in the study. Thirteen nails were DP-OM, and 23 nails were DP-TO. The demographic data and risk factors for the 2 groups were not significantly different. Dermatophytoma lesions were found on the lateral side of nails in 12 cases of DP-OM (92.3%) and 11 cases of DP-TO (47.8%; P = 0.008). DP-OM was associated with longitudinal striae adjacent to dermatophytoma (69.2% vs. 30.4%; P = 0.024), sulfur-nugget-like subungual debris (23.1% vs. 0%; P = 0.040), and scale on the ipsilateral foot (69.2% vs. 8.7%; P < 0.001). DP-TO was associated with a homogenous, whitish discoloration (47.8% vs. 7.7%; P = 0.014) and a sharp edge of the onycholytic area (43.5% vs. 0%; P = 0.005). Conclusions: The lateral location of dermatophytoma, adjacent striae, sulfur-nugget-like debris, and scale on the ipsilateral foot were significantly associated with DP-OM. Dermoscopic examination (dorsal and hyponychium views) and foot examination are beneficial for distinguishing between DP-OM and DP-TO.

Invasive Fatal Scopulariopsis brevicaulis Infection in Canaries.

Scopulariopsis brevicaulis, a soil saprophyte, is the most common dermatomycotic mould and causes deep fungal infection. Ten canaries died in a flock of 200 and, at necropsy, S. brevicaulis was isolated from lung and beak samples. Macroscopically, the colonies were flat, velvety or powdery, white, tan, dark brown, grey or black. Microscopically, the isolated fungus had hyaline and septate hyphae, finger-like conidiophores on which annelids produced chains of conidia. On histopathological examination, multiple irregular thin red hyphae were seen in lung tissue of the canaries. Although S. brevicaulis may be involved in onychomycosis, pulmonary mycosis or invasive infection in humans, this infection has not been reported in canaries. This study shows that S. brevicaulis can cause invasive and fatal infection in canaries.

Insights on the etiopathogenesis of onychomycosis by dermatophyte, yeast and non-dermatophyte mould in ex vivo model.

Fungal biofilms have been involved in the pathogenesis of onychomycosis, but the aspects contributing to this association need to be enlightened. This study aimed to investigate the ability of three different fungi to form biofilm on the nail. All evaluated fungi were able to grow on the nails, using them as the only nutritional source and formed a structure strongly suggestive of biofilms. However, their architecture and morphology were highly contrasting: Candida albicans showed dense growth, exhibited a well-structured community and a large amount of extracellular matrix (ECM), and FTIR-ATR spectroscopy reinforced these findings revealing components suggestive of the biofilm. For Fusarium oxysporum, these events were also observed, but in lower intensity. Furthermore, while Trichophyton rubrum presented a well-organized architecture, the ECM was not visualized. We hypothesize that these findings are related to the symptomatology of onychomycosis. When it is caused by a non-dermatophyte, it usually is accompanied with paronychia, pain, oedema, inflammation and few signals of keratolysis, while dermatophytes are more associated with intense onycholysis and absence of the inflammatory signals. Biofilm seems to be crucial for non-dermatophytes to cause onychomycosis, but not for T. rubrum.

Epidemiología de la Onicomicosis Pedis en adultos hospitalizados en un servicio de medicina en un hospital de tercer nivel en Chile / Epidemiology of Onychomycosis pedisinhospitalized adults at the internal medicine ward of a high complexity hospital in Chile

La prevalencia global de la onicomicosis pedis es de 4,3%, y en hospitalizados puede llegar hasta 8,9%. Aun así, se propone que está ampliamente subdiagnosticada. Personas añosas con comorbilidades presentan mayor riesgo de onicomicosis pedis y de sus complicaciones. Se examinaron aleatoriamente a 64 pacientes hospitalizados en el Servicio de Medicina del Hospital San José. A aquellos con signos clínicos de onicomicosis pedis se les realizó un examen micológico directo (MD) y estudio histopatológico de un corte de uña teñido con PAS (Bp/PAS). Muestra de 64 pacientes, un 78,1% presentó onicomicosis pedis clínica y en un 70,3% se confirmó el diagnóstico con MD y/o Bp/PAS positivo. De los pacientes con onicomicosis confirmada, el promedio de edad fue de 67,8 +/- 12,3 años. Un 44% correspondió al sexo femenino y un 56% al sexo masculino. La onicomicosis pedis en el servicio de medicina interna del Hospital San José es una condición frecuente. El conjunto de MD y Bp/PAS podría ser considerado como una buena alternativa diagnóstica. (AU)

Onychomycosis of the toenails has a global prevalence of 4,3% and can reach up to 8,9% in hospitalized patients. It has been hypothesized that it is widely under diagnosed. Aged patients with multiple diseases have an increased risk of Onychomycosis and its complications. 64 patients of the internal medicine ward were randomly selected. Those who had clinical signs of onychomycosis of the toenails were tested with direct microscopy and histological study of the nail plate with PAS staining. Of the 64 patients, 78,1% (50) had clinical signs of onychomycosis of the toenails and in 70,3% (45) the diagnosis was confirmed either by direct microscopy and/or by histological study of the nail plate with PAS staining. The mean age for the group with onychomycosis was 67,8 +/- 12,3 ages. 44% were female and 56% were male. Onychomycosis of the toenails is a frequent condition at the internal medicine ward of the San José Hospital. The direct microscopy together with the histological study of the nail plate with PAS staining seem to be a good diagnosis alternative. (AU)

Onychoscopy in a Colombian population with a diagnosis of toenail onychomycosis: an evaluation study for this diagnostic test.

BACKGROUND: Onychoscopy is a technique that uses a dermatoscope for the evaluation of specific features of different skin conditions that are not visible to the naked eye. There are few studies establishing parameters for the diagnosis of onychomycosis based on onychoscopy. Determining the sensitivity and specificity of a potentially new diagnostic test for onychomycosis requires an evaluation study of this new diagnostic test, as there are limited studies reporting onychoscopy results. AIM: To determine the sensitivity, specificity, positive predictive value and negative predictive value of onychoscopy findings in a Colombian population with onychomycosis. METHODS: We assessed outpatients with a diagnosis of toenail onychomycosis confirmed by potassium hydroxide preparation or fungal culture. Onychoscopy was performed using a dermatoscope, and digital images collected using a smartphone. RESULTS: The onychoscopy findings were: longitudinal striae, distal spiked pattern, distal irregular termination, linear edge and ruins aspect, while some patients were confirmed as having traumatic onycholysis. A statistically significant association was found between the clinical symptoms of onychomycosis and both the clinical feature of dyschromia and the onychoscopy feature of longitudinal striae. CONCLUSION: We suggest that this technique is an alternative method that should be used in patients with onychopathies because it has the potential to differentiate onychomycosis from traumatic onycholysis and another nail involvement.

A Case of Tinea Faciei, Tinea Corporis, and Tinea Unguium with Dermatophytoma Successfully Treated with Oral Fosravuconazole L-lysine Ethanolate.

We present a 76-year-old Japanese male with tinea faciei, tinea corporis, and tinea unguium with dermatophytoma. We performed fungal culture and confirmed the causative fungus to be Trichophyton rubrum. We treated the patient using oral fosravuconazole l-lysine ethanolate (F-RVCZ). More than one year has passed since the end of treatment, but there has been no recurrence. This case suggests that F-RVCZ is effective for tinea other than tinea unguium.

Identification and in vitro antifungal susceptibility of causative agents of onychomycosis due to Aspergillus species in Mashhad, Iran.

Aspergillus species are emerging causative agents of non-dermatophyte mold onychomycosis. In this study, 48 Aspergillus isolates were obtained from patients with onychomycosis in Mashhad, Iran, during 2015-2018. The aim is to identify the Aspergillus isolates to the species level by using partial calmodulin and beta-tubulin gene sequencing and MALDI-TOF MS, and to evaluate their in vitro susceptibility to ten antifungal drugs: terbinafine, itraconazole, voriconazole, posaconazole, ravuconazole, isavuconazole, caspofungin, micafungin, anidulafungin and amphotericin B according to CLSI M38-A3. Our results indicate that A.flavus (n = 38, 79%) is the most common Aspergillus species causing onychomycosis in Mashhad, Iran. Other detected species were A. terreus (n = 3), A. tubingensis (n = 2), A. niger (n = 1), A. welwitschiae (n = 1), A. minisclerotigenes (n = 1), A. citrinoterreus (n = 1) and A. ochraceus (n = 1). Aspergillus flavus, A. terreus and A. niger isolates were correctly identified at the species level by MALDI-TOF MS, while all cryptic species were misidentified. In conclusion, A. flavus is the predominant Aspergillus species causing onychomycosis due to Aspergillus spp. in Mashhad, Iran. MALDI-TOF MS holds promise as a fast and accurate identification tool, particularly for common Aspergillus species. It is important that the current database of reference spectra, representing different Aspergillus species is expanded to increase the precision of the species-level identification. Terbinafine, posaconazole and echinocandins were in vitro most active against the studies Aspergillus isolates and terbinafine could be the first choice for treatment of onychomycosis due to Aspergillus.

Dermatophytic melanonychia: A case series of an increasing disease.

BACKGROUND: Melanonychia refers to brown-black colour pigmentation due to melanin or not-melanin deposition in the nail plate. Onychoscopy allows to distinguish if the pigmentation is due by melanin or not. The main causes of non-melanic pigmentation are subungual haematoma and pigmented onychomycosis. Fungal melanonychia (FM) is rare and may present as diffuse or longitudinal pigmentation. Differential diagnosis includes melanic activation, such as ethnic-type nail pigmentation or frictional melanonychia, but also versus melanic proliferation, such as nevus or nail melanoma. Fungal melanonychia can be due to a colonisation by fungi with black variant or by melanin activation due to inflammation of fungal invasion. OBJECTIVES: The aim of paper is to increase clinical and dermoscopic knowledge of this increasingly frequent disease. METHODS: In this retrospective observational study, twenty patients with dermatophytic melanonychia were collected, with available clinical and dermoscopic pictures. The diagnosis of dermatophytic melanonychia was made based on clinical manifestation and mycological examination. KOH smear was performed in all cases. For each patient, clinical data included: age, gender, type of melanonychia and involved fingers. RESULTS: This study aimed to show increased incidence of dermatophytic melanonychia and its correct management. In addition, we reviewed our collected cases and described the clinical and dermoscopic features of dermatophytic melanonychia. CONCLUSIONS: The results of this study showed that physicians should keep in mind the diagnosis of this increasing disease, and that it cannot be performed relying only on clinical grounds. We would like to highlight the importance of tools as KOH examination, culture and dermoscopy.

Direct examination, histopathology and fungal culture for the diagnosis of onychomycosis: A retrospective, comparative study on 2245 specimens.

BACKGROUND: Onychomycosis affects 5.5% of the general population and represents up to 50% of all nail diseases. Diagnosis and pathogen identification are essential in order to plan an adequate treatment. Many diagnostic techniques are available, and however, no solid data regarding comparison between different techniques over a large number of specimens are available to date. OBJECTIVES: To compare sensitivity and specificity of direct examination, histopathology and fungal culture in our referral mycology laboratory. METHODS: Nail specimens received at the cutaneous pathology and mycology laboratory of the University Hospital Saint-Pierre (Brussels, Belgium) between 1 January and 15 May 2018 were retrospectively analysed. All specimens were submitted to direct examination and culture. In cases of adequate specimen size, histopathology was performed. Fungal culture was considered the gold standard for diagnosis. RESULTS: A total of 2245 nail samples were included in the study. Onychomycosis was diagnosed in 1266 specimens. Sensitivity and positive predictive value were found to be higher for direct examination compared to histopathology, while sensitivity of direct examination was found to be lower. Combined approach with all the three techniques showed the highest rate of positivity, followed by the association of direct examination and histopathology. CONCLUSIONS: To our knowledge, this study included the largest number of nail specimens to date, allowing a comparison between direct examination, culture and histopathology. Direct examination showed to be the most performing technique in routine practice. Histopathology represents the most effective option in cases where both specimen size and laboratory resources are adequate. Our paper adds to the literature the 'real-life' experience of the mycology laboratory of a referral centre for nail diseases.

Development of an Animal Model of Onychomycosis in Guinea Pigs.

Onychomycosis is a common and intractable superficial mycosis that occurs worldwide. Treatment with both oral and topical drugs is recommended, but the objective evaluation procedure to determine the efficacy of and the appropriate delivery system for the drugs remains controversial. This may be attributed to the lack of a reliable animal model that not only mirrors the pathophysiology of human onychomycosis but is also feasible. Therefore, we attempted to establish an animal model of onychomycosis using immunosuppressed guinea pigs and elucidate the pathophysiology of human onychomycosis. In the present study, we applied Trichophyton mentagrophytes TIMM2789 to the hind limb nails of corticosteroid-treated guinea pigs. The nails were examined macroscopically and histopathologically at 0, 14, and 42 days after a 2-week exposure period to the fungus. A large portion of the experimentally infected nails showed discoloration, which is an important clinical sign, and most infections were confirmed histopathologically in the deep layer of the nail plate at all time points. The infection rates at 0, 14, and 42 days after exposure were 39%, 61%, and 78%, respectively. Thus, we established an animal model of onychomycosis with good reproducibility and that might be appropriate for extrapolation to the pathophysiology of the human disease.

Non-dermatophyte Mould Onychomycosis in Japan.

The incidence of non-dermatophyte mould onychomycosis has been increasing worldwide for the past several decades, but it is not well recognized in Japan. Recent molecular techniques and phylogenetic analyses contributed to the identification of uncommon and emerging species. We came across 13 (0.5%) cases of non-dermatophyte onychomycosis among a total of 2,591 onychomycosis cases in 106,703 outpatients during the past 5 years (January 2015-December 2019). The cases included 5 patients with Aspergillus species, 4 patients with Fusarium species, and one patient each with Scopulariopsis brevicaulis and Botryosphaeria dothidea, respectively. Botryosphaeria dothidea is closely related phylogenetically to Neoscytalidium dimidiatum. In Japan, at the time of writing this report, there are 26 reported cases of ungual aspergillosis and 18 cases of hyalohyphomycosis caused by Fusarium species. We summarize these cases and report the symptoms and mycological features.

Usefulness of Wood's Lamp for the Diagnosis and Treatment Follow-up of Onychomycosis.

Wood's lamp was demonstrated to be useful in three cases of dermatophytoma treated during clinical dermatological practice. Clinical signs of onychomycosis are longitudinal yellow and white striae on the nail plate and are diagnosed by KOH direct microscopic examination. For its treatment, surgical debridement is recommended. Usefulness of the Wood's lamp for diagnosis of tinea capitis caused by Microsporum canis is standard. In the first and second cases, we used Wood's lamp (Woody™) to make a clear margin for debridement of onychomycosis. In the third case, onychomycosis was unsuccessfully treated using topical 5% luliconazole nail solution for 1 year and 10 months with yellow nail discoloration. Under Wood's lamp, we were able to distinguish luliconazole crystal staining from onychomycosis. This method is simple and quick, and useful for nail observation in dermatology clinics.

Keratin Biomembranes as a Model for Studying Onychomycosis.

Difficulties in obtaining human nails that are large enough for examining the penetration of drug formulations led us to produce keratin films regenerated from human hair. We assume that these films can simulate human nail plates in drug penetration and permeation tests and can serve as a biological model for studying onychomycosis. The films were formed from keratin extracted from human hair using dithiothreitol, urea and thiourea. The obtained keratin extract was dispensed into Teflon rings and dried at 40 °C and then cured at 110 °C. The structure, surface morphology, chemical characterization and thermal stability of the films were characterized and were compared to those of human nail, hair and bovine hoof samples using SDS-electrophoresis, scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The structure of the obtained films was found to be closer to human nails than to hair or bovine hooves. The keratin films were infected with Trichophyton rubrum and were proven to be appropriate for serving as a model for studying onychomycosis.