Dual quantitative PCR assays for the rapid detection of Trichophyton indotineae from clinical samples.

Trichophyton indotineae is an emerging species of the Trichophyton mentagrophytes complex (TMC), responsible for an epidemic of widespread hairless skin infections that is frequently (50-70%) resistant to terbinafine. In order to initiate appropriate treatment as quickly as possible without waiting for culture positivity (10-15 days) and molecular identification from the strain, we developed a dual quantitative PCR (qPCR) for the direct detection of T. indotineae in clinical samples. We first designed a T. indotineae-specific qPCR assay (TI-qPCR) targeting a single specific polymorphism in the internal transcribed spacer region. Although none of the 94 non-dermatophyte and 7 dermatophyte species were amplified, this TI-qPCR allowed amplification of other TMC species at a lower yield. With equal amounts (0.1 ng) of DNA per reaction, the mean quantitative cycle (Cq) values for T. indotineae and non-indotineae TMC were 27.9 (±0.1) and 38.9 (±0.3), respectively. Therefore, we normalized this assay against a previously validated pan-dermatophyte qPCR assay (PD-qPCR) and relied on the ΔCq [(TI-qPCR) - (PD-qPCR)] to identify T. indotineae versus other TMC species. Dual assay was validated using 86 clinical samples of culture-confirmed T. indotinea and 19 non-indotineae TMC cases. The mean ΔCq for non-indotineae TMC was 9.6 ± 2.7, whereas the ΔCq for T. indotinea was -1.46 ± 2.1 (P < .001). Setting the ΔCq at 4.5 as a cutoff value resulted in 100% specificity for the detection of T. indotineae. This dual qPCR assay quickly detects T. indotineae from skin scrapings, aiding in early diagnosis and treatment for patients with suspected infection.

Identifying the emerging species Trichophyton indotineae is long and requires to wait for culture positivity. We developed a dual qPCR strategy to detect T. indotineae directly from clinical sample with a 100% sensitivity.

Clinico-mycological and therapeutic updates on cutaneous dermatophytic infections in the era of Trichophyton indotineae.

Trichophyton indotineae has emerged as a novel dermatophyte species resulting in treatment recalcitrant skin infections. While the earliest reports came from India, T. indotineae has now spread to many parts of the world and is rapidly becoming a global health concern. Accurate identification of T. indotineae requires elaborate mycological investigations which is beyond the domain of routine microbiology testing. Extensive, non-inflammatory and atypical presentations are commonly seen with this novel species. T. indotineae shows an alarmingly high rate of mutations in the squalene epoxidase gene leading to lowered in vitro susceptibility to terbinafine. This has also translated into a lowered clinical response and requirement of a higher dose and much longer durations of treatment with the drug. Although the species remains largely susceptible to itraconazole, prolonged treatment durations are required to achieve cure with itraconazole. Fluconazole and griseofulvin do not have satisfactory in vitro or clinical activity. Apart from requirement of prolonged treatment durations, relapse postsuccessful treatment is a distressing and yet unexplained consequence of this "species-shift." Use of third generation azoles and combinations of systemic antifungals is unwarranted as both have not demonstrated clear superiority over itraconazole given alone, and the former is an important class of drugs for invasive mycoses.

Chrysosporium articulatum mimicking Trichophyton spp. infection in a cat: a case presentation and literature review.

BACKGROUND: Dermatophytosis is a common skin infection of cats and many other animals. A reliable diagnosis is crucial because of the zoonotic potential of dermatophytes. The routine mycological diagnostic procedures for dermatophytosis are widely known, but in the case of some isolates, identification based on phenotypic characteristics may be incorrect. Infections caused by Chrysosporium spp. are usually described in reptiles, but in other animals they are uncommon. CASE PRESENTATION: This study presents a description of a cat with dermatological lesions, that was mistakenly diagnosed with Trichophyton spp. dermatophytosis. Clinical material for mycological examination was collected from alopecic areas on the back of the neck, the ventral abdomen, and the hindlimbs. The initial identification based on phenotypic properties indicated Trichophyton spp. The result of the MALDI-ToF MS allowed the exclusion of the Trichophyton genus. Ultimately, the correct identification as Chrysosporium articulatum was obtained based on the sequencing of ribosomal genes. CONCLUSIONS: Interpretation of the results of the mycological examination of samples collected from animals' skin or hair shafts is always challenging. Thus, careful consideration of the primary cause of the clinical lesions observed on the skin is mandatory, and the culture results are worth supporting by molecular methods.

A clinical prevalence of dermatophytic mycoses with an assessment of its clinical manifestations in a tertiary care hospital at Salem, South India.

BACKGROUND: Dermatophytosis is very common among all age groups throughout the world. The incidence of the same is increasing on a steady basis. AIM: Estimating the clinical prevalence of dermatophytes mycoses among the patients visiting the outpatient unit and assessing its distinct manifestations. METHODOLOGY: A prospective observational study was conducted with the patients attending the Skin and STD outpatient unit of a tertiary care teaching hospital in Salem. A total of 3068 outpatients attended the department, of which 420 patients were diagnosed with dermatophytic mycoses and were taken for investigating the prevalence. RESULTS: A total of 420 dermatophytosis patients were included giving a percentage prevalence of 13.69%. There were more female patients (n = 213, 50.71%) than males (n = 207, 49.29%). The most common afflicted age group was 31-40 years (n = 99, 50.71%). Most of the patients had an atypical lesion called tinea incognita (n = 265, 63.09%) where there was no typical classic appearance of dermatophytic infections. The most prevalent clinical manifestation was tinea corporis (n = 73, 17.38%) followed by tinea cruris (n = 69, 16.43%). There were more newly diagnosed dermatophytosis cases (n = 326) than the previously diagnosed cases (n = 94). CONCLUSION: This study concludes that dermatophytic mycoses were more prevalent among females than males and among the age groups of 31-40 years. The most common clinical presentation was tinea incognita followed by tinea corporis.

Identification of primary metabolites in fungal species of Trichophyton mentagrophyte and Trichophyton rubrum by NMR spectroscopy.

BACKGROUND: Superficial mycoses are fungal infections limited to the outermost layers of the skin and its appendages. The chief causative agents of these mycoses are dermatophytes and yeasts. The diagnosis of dermatophytosis can be made by direct mycological examination with potassium hydroxide (10%-30%) of biological material obtained from patients with suspected mycosis, providing results more rapid than fungal cultures, which may take days or weeks. This information, together with clinical history and laboratory diagnosis, ensures that the appropriate treatment is initiated promptly. However, false negative results are obtained in 5%-15%, by conventional methods of diagnosis of dermatophytosis. OBJECTIVES: To study the metabolic profiles of the commonly occurring dermatophytes by NMR spectroscopy. PATIENTS/MATERIALS: We have used 1D and 2D Nuclear Magnetic Resonance (NMR) experiments along with Human Metabolome Database (HMDB) and Chenomx database search for identification of primary metabolites in the methanol extract of two fungal species: Trichophyton mentagrophyte (T. mentagrophyte) and Trichophyton rubrum (T. rubrum). Both standard strains and representative number of clinical isolates of these two species were investigated. Further, metabolic profiles obtained were analysed using multivariate analysis. RESULTS: We have identified 23 metabolites in the T. mentagrophyte and another 23 metabolites in T. rubrum. Many important metabolites like trehalose, proline, mannitol, acetate, GABA and several other amino acids were detected, which provide the necessary components for fungal growth and metabolism. Altered metabolites were defined between Trichophyton mentagrophyte and T. rubrum strains. CONCLUSION: We have detected many metabolites in the two fungal species T. mentagrophyte and T. rubrum by using NMR spectroscopy. NMR spectroscopy provides a holistic snapshot of the metabolome of an organism. Key metabolic differences were identified between the two fungal strains. We need to perform more studies on metabolite profiling of the samples from these species for their rapid diagnosis and prompt treatment.

Clinico-mycological validation of dermatophytosis severity score and its correlation with patient-reported outcome measures.

BACKGROUND: Dermatophytosis impacts a significant portion of the global population. Recent shifts in the disease's presentation, severity and response to treatment, primarily due to emerging drug resistance, underscore the need for reliable assessment tools. The Dermatophytosis Severity Score (DSS) aims to standardise the evaluation of the disease's severity and monitor therapeutic responses. METHODS: In a cross-sectional pilot study, 25 adults with clinically diagnosed dermatophytosis were evaluated using the DSS. The study also aimed to establish the correlation of DSS with different stages of treatment, dermatophyte species and patient-reported outcomes. Participants were recruited from a dermatology outpatient clinic, and the DSS was applied at baseline, Weeks 4 and 8. The validity and reliability of the DSS were assessed using statistical measures, including Cronbach's alpha and intraclass correlation coefficient. RESULTS: The study comprised of a near-equal distribution of male (52%) and female (48%) patients, primarily within the age group of 20-39 years. A high recurrence rate of dermatophytosis (60%) was noted, and more than half of the patients (56%) had used topical steroids before presentation. The mean DSS significantly decreased from baseline to the final visit, mirroring the substantial reduction in the 5D itch scale and Dermatology Life Quality Index, with strong positive correlations observed between these measures. CONCLUSION: The DSS demonstrated high inter-rater reliability and internal consistency, indicating its utility as a reliable clinical tool for assessing dermatophytosis severity. The strong correlation of DSS with itch intensity and quality of life validates its role in patient-centered care. Continued use and further validation of the DSS are recommended to enhance dermatophytosis management and treatment outcomes.

Chinese expert consensus on management of antifungal-resistant dermatophytoses (2024 edition).

Antifungal-resistant dermatophytes (ARD) infection is a hotspot issue in clinical microbiology and the dermatology field. Trichophyton indotineae as the dominant species of dermatophyte with terbinafine-resistance or multidrug resistance, is easy to be missed detection clinically, which brings severe challenges to diagnosis and treatment. ARD infection cases have emerged in China, and it predicts a risk of transmission among human. Based on the existing medical evidence and research data, the Mycology Group of Combination of Traditional and Western Medicine Dermatology and Chinese Antifungal⁃Resistant Dermatophytoses Expert Consensus Group organized experts to make consensus on the management of the infection. Here, the consensus formulated diagnosis and treatment recommendations, to raise attention to dermatophytes drug resistance problem, and expect to provide reference information for the clinical diagnosis, treatment, prevention and control.

Inappropriate Use of Steroids in Superficial Dermatophytosis: An Uncommon Case of Erythroderma.

Erythroderma is a dermatological emergency presenting with generalized erythema and scaling involving <90% of the body surface.1 There are various causes of erythroderma, such as psoriasis, atopic dermatitis, phytophotodermatitis, pityriasis rubra pilaris, pemphigus foliaceus, cutaneous T-cell lymphoma, and drug eruptions.2 However, erythroderma induced by dermatophytosis is encountered rarely. We, here, describe a case of erythroderma developed secondary to extensive dermatophytosis.

Nannizzia polymorpha as Rare Cause of Skin Dermatophytosis.

Nannizzia polymorpha is a dermatophyte that rarely infects humans. We describe 2 case-patients from Asia who had an inflammatory type of tinea capitis and tinea manuum caused by infection with this fungus. The diagnosis was confirmed on the basis of the morphologic and molecular characteristics of the microorganism.

Sexually Transmitted Trichophyton mentagrophytes Genotype VII Infection among Men Who Have Sex with Men.

Transmission of dermatophytes, especially Trichophyton mentagrophytes genotype VII, during sexual intercourse has been recently reported. We report 13 such cases in France. All patients were male; 12 were men who have sex with men. Our findings suggest sexual transmission of this pathogen within a specific population, men who have sex with men.

Defining the relationship between phylogeny, clinical manifestation, and phenotype for Trichophyton mentagrophytes/interdigitale complex; a literature review and taxonomic recommendations.

This study looked for correlations between molecular identification, clinical manifestation, and morphology for Trichophyton interdigitale and Trichophyton mentagrophytes. For this purpose, a total of 110 isolates were obtained from Czech patients with various clinical manifestations of dermatophytosis. Phenotypic characters were analyzed, and the strains were characterized using multilocus sequence typing. Among the 12 measured/scored phenotypic features, statistically significant differences were found only in growth rates at 37 °C and in the production of spiral hyphae, but none of these features is diagnostic. Correlations were found between T. interdigitale and higher age of patients and between clinical manifestations such as tinea pedis or onychomychosis. The MLST approach showed that internal transcribed spacer (ITS) genotyping of T. mentagrophytes isolates has limited practical benefits because of extensive gene flow between sublineages. Based on our results and previous studies, there are few taxonomic arguments for preserving both species names. The species show a lack of monophyly and unique morphology. On the other hand, some genotypes are associated with predominant clinical manifestations and sources of infections, which keep those names alive. This practice is questionable because the use of both names confuses identification, leading to difficulty in comparing epidemiological studies. The current identification method using ITS genotyping is ambiguous for some isolates and is not user-friendly. Additionally, identification tools such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry fail to distinguish these species. To avoid further confusion and to simplify identification in practice, we recommend using the name T. mentagrophytes for the entire complex. When clear differentiation of populations corresponding to T. interdigitale and Trichophyton indotineae is possible based on molecular data, we recommend optionally using a variety rank: T. mentagrophytes var. interdigitale and T. mentagrophytes var. indotineae.

Species in the T. mentagrophytes complex lack support from usual taxonomic methods and simple identification tools are missing or inaccurate. To avoid recurring confusions, we propose naming the entire complex as T. mentagrophytes and optionally use rank variety to classify the observed variability.

Sheep serve as a reservoir of Trichophyton mentagrophytes genotype V infection.

Human infections by Trichophyton mentagrophytes occur mainly due to contact with diseased animals. In Iran, T. mentagrophytes genotype V is the most prevalent variant of the fungus. We aimed to determine the animal reservoir of T. mentagrophytes genotype V infection. The study was done on a total of 577 dermatophyte strains obtained from animals with signs of dermatophytosis and human patients. The list of extensively sampled animals included sheep, cows, cats and dogs. For human cases, epidemiological data were collected. All dermatophyte isolates from animals along with 70 human isolates morphologically similar to T. verrucosum and T. mentagrophytes genotype V were identified by rDNA internal transcribed spacer region restriction fragment length polymorphism analysis and DNA sequencing. A total of 334 animal dermatophyte strains were identified as Microsporum canis, T. mentagrophytes genotype V, T. verrucosum, Nannizzia gypsea, T. mentagrophytes genotype II*, T. mentagrophytes genotype VII, T. quinckeanum, and N. fulva. All clinical isolates identified as T. mentagrophytes genotype V originated from skin and scalp infections. Almost all veterinary isolates of T. mentagrophytes genotype V were cultured from sheep, but epidemiological data on animal-to-human transmission of T. mentagrophytes genotype V infection were limited and we found evidence in favor of interhuman transmission. In Iran, sheep maintain T. mentagrophytes genotype V population and therefore serve as animal reservoir of respective infections. The role of sheep as the source of human dermatophytosis due to T. mentagrophytes genotype V isolates is yet to be proven.

In this study, we sampled a variety of animals to determine a reservoir of Trichophyton mentagrophytes genotype V infection. With the use of molecular identification techniques, we show that this infection reservoir is represented by sheep.

Erythroderma combined with deeper dermal dermatophytosis due to Trichophyton rubrum in a patient with myasthenia gravis: first case report and literature review.

BACKGROUND: Dermatophytes are the most common causative pathogens of mycoses worldwide and usually cause superficial infections. However, they can enter deep into the dermis lead to invasive dermatophytosis such as deeper dermal dermatophytosis on rare occasions. Erythroderma is a severe dermatological manifestation of various diseases resulting in generalized skin redness, but erythroderma due to fungi infections is barely reported. In this article, we reported the first case of erythroderma combined with deeper dermal dermatophytosis due to Trichophyton rubrum (T. rubrum) in a patient with myasthenia gravis. CASE PRESENTATION: A 48-year-old man was hospitalized because of erythema with scaling and nodules covering his body for a month. The patient had a history of myasthenia gravis controlled by regularly taking prednisolone for > 10 years and accompanied by onychomycosis and tinea pedis lasting > 8 years. Based on histopathological examinations, fungal cultures, and DNA sequencing results, the patient was finally diagnosed with dermatophyte-induced erythroderma combined with deeper dermal dermatophytosis caused by T. rubrum. After 2 weeks of antifungal treatment, the patient had recovered well. CONCLUSIONS: This case report shows that immunosuppressed patients with long histories of superficial mycoses tend to have a higher risk of developing invasive dermatophytic infections or disseminated fungal infections. Dermatologists should be alert to this condition and promptly treat the superficial dermatophytosis.

Time and cost-efficient identification of Trichophyton indotineae.

BACKGROUND: During the past 5 years, an outbreak of recalcitrant dermatophytosis due to a novel Trichophyton species generally resistant to terbinafine, T. indotineae, has spread out from South Asia to many countries around the World. These isolates cannot be reliably differentiated from other Trichophyton spp. on the basis of morphological traits and the current laboratory diagnostics relies on sequencing of ribosomal DNA ITS region. OBJECTIVES: In this study, we aimed to introduce two inexpensive and rapid PCR-based assays for differentiation between T. indotineae and other dermatophytes. METHODS: The first introduced assay is based on PCR-restriction fragment length polymorphism (PCR-RFLP) analysis, involving the amplification of TOP2 sequences and the digestion of PCR products by Cfr13I restriction enzyme. The second assay is proposed as conventional endpoint species-specific PCR amplification of the C120-287 intergenic locus. To validate the assays, a total of 191 Trichophyton spp. and 2 Microsporum canis strains with known ITS region sequences were used. From the T. mentagrophytes / T. interdigitale species complex (TMTISC), strains with 18 different ITS genotypes were tested. The sample of TMTISC isolates included 41 T. indotineae strains. RESULTS: TOP2 PCR-RFLP and T. indotineae-specific PCR were positive with testing on DNA of all 41 T. indotineae isolates and two strains of T. mentagrophytes belonging to ITS Types XIII and XVI, but negative with other species and other TMTISC ITS genotypes (n = 152). Therefore, the specificity of both new assays was 99%. CONCLUSION: The two developed diagnostic assays provide accurate and cost-effective means of identifying cultured T. indotineae isolates.

Dermatophytoses Severity Score - A novel point-of-care scoring tool to assess the severity of dermatophytosis.

The rising prevalence of dermatophytosis in tropical countries coupled with drug resistance necessitates an objective scoring system to define the severity, monitor therapeutic response and predict prognoses. We attempted to establish and validate a new scoring system - Dermatophytoses Severity Score (DSS), for dermatophytoses affecting non-glabrous skin. A consensus group was convened to develop an objective and reproducible scoring system to describe the extent and severity of dermatophytosis of 200 consecutive patients with dermatophytosis. A second assessment entailed independent DSS scoring of the same patients by dermatologists and residents who were not part of the consensus group. The main outcome measured was index reliability, assessed in two steps, between the observers. A two-step assessment and DSS grading of 200 consecutive patients with clinically diagnosed dermatophytoses showed high reliability (Cronbach's α test and intraclass correlation coefficient). The DSS has demonstrated high reliability, and it could serve as a novel, reproducible and objective scoring tool for dermatophytosis.

Tinea capitis caused by Trichophyton tonsurans among adults: Clinical characteristics and treatment response.

BACKGROUND: Trichophyton tonsurans tinea capitis has become a growing epidemiological concern. Yet, its clinical manifestations and treatment response, specifically among adults, have only been described among small sample size studies. OBJECTIVE: To assess clinical manifestations and treatment outcome of T. tonsurans tinea capitis among adults. PATIENTS AND METHODS: A retrospective cohort study was carried out among 111 adults with T. tonsurans tinea capitis. Diagnosis was confirmed by fungal culture or polymerase chain reaction. Examinees' demographics, disease characteristics and treatment response were measured. The risk factors for the treatment failure were evaluated. RESULTS: The mean age was 20.1 years (±3.1), with men (98.2%) outnumbering women. The follow-up lasted 12.2 months (±5.6). The majority of T. tonsurans tinea capitis was seen in the occipital area (87.6%). In 78.9% of the cases, the scalp manifestation was non-inflammatory (scaly plaques and papules:76.1% and seborrhoea-like: 2.8%). 21.1% of cases presented with inflammatory tinea capitis (21.1%; Kerion: 10.1% and pustular: 11%). Concomitant involvement of other than scalp areas was common: tinea corporis was seen in 38.7% of the cases; tinea faciei and barbae in 24.3%; nape and anterior neck in 76.6% and 2.7% of the cases, respectively. An adequate treatment course with oral terbinafine resulted in 83.2% clinical cure rate. Treatment failure was significantly associated with concomitant tinea corporis (odds ratio 3.9; 95% confidence interval 1.3-12.1, p-Value< .02). CONCLUSION: The most common clinical presentation of T. tonsurans tinea capitis included occipital scaly plaques and papules with concomitant non-scalp lesions. Oral terbinafine was found to be highly effective. Concomitant tinea corporis increased the risk for treatment failure.

Reliable and rapid identification of terbinafine resistance in dermatophytic nail and skin infections.

BACKGROUND: Fungal infections are the most frequent dermatoses. The gold standard treatment for dermatophytosis is the squalene epoxidase (SQLE) inhibitor terbinafine. Pathogenic dermatophytes resistant to terbinafine are an emerging global threat. Here, we determine the proportion of resistant fungal skin infections, analyse the molecular mechanisms of terbinafine resistance, and validate a method for its reliable rapid identification. METHODS: Between 2013 and 2021, we screened 5634 consecutively isolated Trichophyton for antifungal resistance determined by hyphal growth on Sabouraud dextrose agar medium containing 0.2 µg/mL terbinafine. All Trichophyton isolates with preserved growth capacity in the presence of terbinafine underwent SQLE sequencing. Minimum inhibitory concentrations (MICs) were determined by the broth microdilution method. RESULTS: Over an 8-year period, the proportion of fungal skin infections resistant to terbinafine increased from 0.63% in 2013 to 1.3% in 2021. Our routine phenotypic in vitro screening analysis identified 0.83% (n = 47/5634) of Trichophyton strains with in vitro terbinafine resistance. Molecular screening detected a mutation in the SQLE in all cases. Mutations L393F, L393S, F397L, F397I, F397V, Q408K, F415I, F415S, F415V, H440Y, or A398 A399 G400 deletion were detected in Trichophyton rubrum. Mutations L393F and F397L were the most frequent. In contrast, all mutations detected in T. mentagrophytes/T. interdigitale complex strains were F397L, except for one strain with L393S. All 47 strains featured significantly higher MICs than terbinafine-sensitive controls. The mutation-related range of MICs varied between 0.004 and 16.0 µg/mL, with MIC as low as 0.015 µg/mL conferring clinical resistance to standard terbinafine dosing. CONCLUSIONS: Based on our data, we propose MIC of 0.015 µg/mL as a minimum breakpoint for predicting clinically relevant terbinafine treatment failure to standard oral dosing for dermatophyte infections. We further propose growth on Sabouraud dextrose agar medium containing 0.2 µg/mL terbinafine and SQLE sequencing as fungal sporulation-independent methods for rapid and reliable detection of terbinafine resistance.

The Persistence of Nystatin Use for Dermatophyte Infections.

BACKGROUND: Despite the limited use of nystatin for tinea infections, physicians may continue to use it. METHODS: We assessed the National Ambulatory Medical Care Survey for all to determine the extent of topical nystatin use in tinea infections. RESULTS: Topical nystatin was used at 4.3% (2.1%, 6.0%) of all tinea infection visits. It was not used at visits with dermatologists and was most common among family medicine physicians (P=.02). DISCUSSION: Physicians are continuing to use nystatin for the treatment of tinea infections. Dermatologists have discontinued this treatment regimen, whereas other specialties have an opportunity to further improve their knowledge in this regard. J Drugs Dermatol. 2023;22(12):e49-e50.     doi:10.36849/JDD.5606e.

Tinea Gladiatorum Detection With a Dermatophyte Test Strip.

OBJECTIVE: Determine sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and concordance of diafactory hs-TP (DTS) to detect tinea gladiatorum using direct potassium hydroxide (KOH) microscopy as the reference standard. DESIGN: Prospective, comparative study. SETTING: Seventeen Minnesota high schools during the winter wrestling season. PATIENTS: Seventy-one consecutive high school wrestlers identified with a suspicious rash during skin inspection. INTERVENTIONS: Samples were obtained from each rash for both DTS and direct KOH microscopy. MAIN OUTCOME MEASURES: Readings were recorded as positive or negative. RESULTS: Direct KOH microscopy identified tinea gladiatorum in 35 of the 71 samples (46%). DTS sensitivity was 80% (95% confidence interval 63%-92%), and specificity was 82% (66%-92%). PPV was 85% (68%-95%), and NPV was 86% (72 %-91%). The DTS result was 83% concordant (72%-91%) with direct KOH microscopy. CONCLUSIONS: Similar to rapid Covid antigen tests, DTS required brief, basic training to perform and gave onsite results in 5 to 30 minutes. Although DTS is not approved for use in the United States by the FDA, concordance compared with direct KOH microscopy in diagnosing tinea gladiatorum was similar to results reported for DTS-TU in tinea unguium and tinea pedis. Further study comparing DTS to a reference standard using PCR plus direct microscopy is warranted.

Dermoscopic Features seen in Tinea Capitis, Tinea Corporis and Tinea Cruris.

BACKGROUND: Superficial fungal infections (SFIs) are infections affecting the keratinized layer of the skin, nail and hair that are mainly caused by dermatophytes. Although diagnosis is routinely done clinically and confirmed by direct potassium hydroxide (KOH) microscopy, fungal culture remains the gold standard for diagnosis and speciation of aetiological agents. Dermoscopy is a recent non-invasive diagnostic tool used to identify features of tinea infections. This study is aimed primarily at identifying specific dermoscopic features seen in tinea capitis, tinea corporis and tinea cruris, and secondarily, to compare dermoscopic features between the three diseases. METHODOLOGY: This is a cross sectional study of 160 patients with suspected superficial fungal infection using a handheld dermoscope. Skin scrapping with 20% KOH microscopy was done, fungal culture was grown on Sabouraud dextrose agar (SDA) and species identified further. RESULTS: There were 20 different dermoscopic features observed in tinea capitis, thirteen in tinea corporis, and twelve in tinea cruris. The commonest dermoscopic feature in tinea capitis was corkscrew hairs, observed in 49 of the 110 patients. This was followed by black dots and comma hairs. There were similar dermoscopic features in tinea corporis and tinea cruris with interrupted hairs and white hairs being the most common features seen respectively. The presence of scales was the dominant feature observed across these three tinea infections. CONCLUSION: Dermoscopy is being used constantly in dermatology practice to improve clinical diagnosis of skin disorders. It has been shown to improve the clinical diagnosis of tinea capitis. We have described the dermoscopic features of tinea corporis and cruris and compared them with that of tinea capitis.

CONTEXTE: Les infections fongiques superficielles (IFS) sont des infections affectant la couche kératinisée de la peau, des ongles et des cheveux, principalement causées par des dermatophytes. Bien que le diagnostic soit systématiquement effectué cliniquement et confirmé par microscopie directe au KOH, la culture fongique reste l'étalon-or pour le diagnostic et la spéciation des agents étiologiques. La dermoscopie est un outil de diagnostic non invasif récent utilisé pour identifier les caractéristiques des infections à tinea. Cette étude vise à identifier les caractéristiques dermoscopiques spécifiques observées dans la tinea capitis, la tinea corporis et la tinea cruris. Ensuite, elle compare les caractéristiques dermoscopiques de ces trois maladies. MÉTHODOLOGIE: Il s'agit d'une étude transversale portant sur 160 patients soupçonnés d'être atteints d'une infection fongique superficielle, réalisée à l'aide d'un dermoscope portatif. Un grattage de la peau avec un microscope à 20 % de KOH a été effectué, une culture fongique a été réalisée sur une gélose dextrose de Sabouraud (SDA) et les espèces ont été identifiées. RÉSULTATS: Vingt caractéristiques dermoscopiques différentes ont été observées dans la tinea capitis, treize dans la tinea corporis et douze dans la tinea cruris. La caractéristique dermoscopique la plus courante dans la tinea capitis était les poils en tire-bouchon, qui ont été observés chez 49 des 110 patients. Viennent ensuite les points noirs et les poils en virgule. La tinea corporis et la tinea cruris présentaient des caractéristiques dermoscopiques similaires, les poils interrompus et les poils blancs étant respectivement les caractéristiques les plus courantes. La présence de squames était la caractéristique dominante observée dans ces trois infections à tinea. CONCLUSION: La dermoscopie est constamment utilisée dans la pratique dermatologique pour améliorer le diagnostic clinique des troubles cutanés. Il a été démontré qu'elle améliorait le diagnostic clinique de la tinea capitis. Nous avons décrit les caractéristiques dermoscopiques des tinea corporis et cruris et les avons comparées à celles de la tinea capitis. Mots clés: Dermoscopiques, Superficielle, Infection fongique, Tinea capitis, Tinea corporis, Tinea cruris.