Diagnostic ability of Peptidase S8 gene in the Arthrodermataceae causing dermatophytoses: A metadata analysis.

An unambiguous identification of dermatophytes causing dermatophytoses is necessary for accurate clinical diagnosis and epidemiological implications. In the current taxonomy of the Arthrodermataceae, the etiological agents of dermatophytoses consist of seven genera and members of the genera Trichophyton are the most prevalent etiological agents at present. The genera Trichophyton consists of 16 species that are grouped as clades, but the species borderlines are not clearly delimited. The aim of the present study was to determine the discriminative power of subtilisin gene variants (SUB1-SUB12) in family Arthrodermataceae, particularly in Trichophyton. Partial and complete reads from 288 subtilisin gene sequences of 12 species were retrieved and a stringent filtering following two different approaches for analysis (probability of correct identification (PCI) and gene gap analysis) conducted to determine the uniqueness of the subtilisin gene subtypes. SUB1 with mean PCI value of 60% was the most suitable subtilisin subtype for specific detection of T.rubrum complex, however this subtype is not reported in members of T. mentagrophytes complex which is one of the most prevalent etiological agent at present. Hence, SUB7 with 40% PCI value was selected for testing its discriminative power in Trichophyton species. SUB7 specific PCR based detection of dermatophytes was tested for sensitivity and specificity. Sequences of SUB7 from 42 isolates and comparison with the ITS region showed that differences within the subtilisin gene can further be used to differentiate members of the T. mentagrophytes complex. Further, subtilisin cannot be used for the differentiation of T. benhamiae complex since all SUB subtypes show low PCI scores. Studies on the efficiency and limitations of the subtilisin gene as a diagnostic tool are currently limited. Our study provides information that will guide researchers in considering this gene for identifying dermatophytes causing dermatophytoses in human and animals.

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.

Potential Sexual Transmission of Tinea Pubogenitalis From TMVII.

This case report describes a patient with Trichophyton mentagrophytes internal transcribed spacer genotype VII resulting in tinea genitalis, glutealis, and corporis.

Common Skin Conditions in Children and Adolescents: Nonbacterial Infections.

Tinea infections are caused by dermatophytes, except for tinea versicolor, which is caused by yeasts in the Malassezia genus. If available, potassium hydroxide preparation should be performed to confirm diagnosis of tinea capitis or onychomycosis. In some cases, fungal culture, UV light examination, or periodic acid-Schiff stain can be helpful. Topical drugs are effective for tinea corporis, tinea cruris, and tinea pedis. Tinea incognito is an atypical presentation that usually requires systemic treatment. Management of tinea capitis always requires oral drugs. Oral drugs are preferred for onychomycosis treatment but should not be prescribed without confirmation of fungal infection. Localized cases of tinea versicolor can be managed with topical drugs, but oral drugs might be needed for severe, widespread, or recurrent cases. Warts are superficial human papillomavirus infections. Common treatments include irritant, destructive (eg, cryotherapy), immune stimulant (eg, intralesional Candida antigen), and debridement and excision methods. Scabies infestation results in intensely itchy papules, nodules, or vesicles. Mites and burrows on the skin are pathognomonic but difficult to identify. Dermoscopy, particularly with UV light, can make identification easier. Topical permethrin and oral ivermectin are two of the most commonly used treatments. All household and close contacts should be treated regardless of the presence or absence of symptoms.

Dermatophytosis in cats: A comprehensive study on diagnostic methods and their accuracy.

Background: Dermatophytosis is a contagious fungal infection that affects mainly cats. It poses significant challenges in veterinary medicine due to its zoonotic potential and impact on animal and public health. Rapid and reliable diagnosis is crucial for preventing the spread of the disease, guiding treatment decisions, and monitoring disease control efforts. Although there are several studies on diagnostic methods in feline dermatophytosis, the comparison between them from the same sample lacks data. The absence of a universally accepted gold standard diagnostic method highlights the need for a multifaceted approach to diagnosing feline dermatophytosis. Aim: This study aims to assess the accuracy and efficacy of different diagnostic techniques comprehensively. Methods: For this, 48 samples of cats were analyzed by dermoscopy, direct hair examination, fungal culture using various media (Mycosel, Sabouraud, and Dermatophyte Test Medium), and polymerase chain reaction (PCR). Results: Direct examination and dermoscopy yielded unsatisfactory results. Mycosel and Sabouraud were suboptimal. DTM demonstrated superior selectivity, making it the most reliable among traditional methods. PCR was the top performer, exhibiting singular sensitivity, specificity, and accuracy. Conclusion: The study suggests that PCR may be the preferred choice for diagnosing feline dermatophytosis in clinical practice, especially when rapid and accurate results are essential.

Dermatophytomas in Onychomycosis: A Scoping Review of Prevalence, Diagnosis, and Treatment.

BACKGROUND: Dermatophytoma, also described as a longitudinal streak/spike, is a form of onychomycosis that presents as yellow/white streaks or patches in the subungual space, with dense fungal masses encased in biofilm. This scoping review of the literature was conducted to address a general lack of information about the epidemiology, pathophysiology, and treatment of dermatophytomas in onychomycosis. METHODS: A search was performed in the PubMed and Embase databases for the terms "longitudinal spike" or "dermatophytoma." Outcomes of interest were definition, prevalence, methods used for diagnosis, treatments, and treatment efficacy. Inclusion and exclusion of search results required agreement between two independent reviewers. RESULTS: Of a total of 51 records, 37 were included. Two reports provided the first unique definitions/clinical features of dermatophytomas. Overall, many descriptions were found, but one conclusive definition was lacking. Prevalence data were limited and inconsistent. The most frequently mentioned diagnostic techniques were clinical assessment, potassium hydroxide/microscopy, and fungal culture/mycology. Oral terbinafine and topical efinaconazole 10% were the most frequently mentioned treatments, followed by topical luliconazole 5% and other oral treatments (itraconazole, fluconazole, fosravuconazole). In studies with five or more patients without nail excision, cure rates were highest with efinaconazole 10%, which ranged from 41% to 100% depending on the clinical and/or mycologic assessment evaluated. Other drugs with greater than or equal to 50% cure rates were topical luliconazole 5% (50%), oral fosravuconazole (57%), and oral terbinafine (67%). In studies that combined oral terbinafine treatment with nail excision using surgical or chemical (40% urea) methods, cure rates ranged from 50% to 100%. CONCLUSIONS: There is little published information regarding dermatophytomas in onychomycosis. More clinical research and physician education are needed. Although dermatophytomas have historically been considered difficult to treat, the efficacy data gathered in this scoping review have demonstrated that newer topical treatments are effective, as are oral antifungals in combination with chemical or surgical methods.

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.

Clinical Course, Antifungal Susceptibility, and Genomic Sequencing of Trichophyton indotineae.

Importance: Trichophyton indotineae is an emerging dermatophyte causing outbreaks of extensive tinea infections often unresponsive to terbinafine. This species has been detected worldwide and in multiple US states, yet detailed US data on infections with T indotineae are sparse and could improve treatment practices and medical understanding of transmission. Objective: To correlate clinical features of T indotineae infections with in vitro antifungal susceptibility testing results, squalene epoxidase gene sequence variations, and isolate relatedness using whole-genome sequencing. Design, Setting, and Participants: This retrospective cohort study of patients with T indotineae infections in New York City spanned May 2022 to May 2023. Patients with confirmed T indotineae infections were recruited from 6 New York City medical centers. Main Outcome and Measure: Improvement or resolution at the last follow-up assessment. Results: Among 11 patients with T indotineae (6 male and 5 female patients; median [range] age, 39 [10-65] years), 2 were pregnant; 1 had lymphoma; and the remainder were immunocompetent. Nine patients reported previous travel to Bangladesh. All had widespread lesions with variable scale and inflammation, topical antifungal monotherapy failure, and diagnostic delays (range, 3-42 months). Terbinafine treatment failed in 7 patients at standard doses (250 mg daily) for prolonged duration; these patients also had isolates with amino acid substitutions at positions 393 (L393S) or 397 (F397L) in squalene epoxidase that correlated with elevated terbinafine minimum inhibitory concentrations of 0.5 µg/mL or higher. Patients who were treated with fluconazole and griseofulvin improved in 2 of 4 and 2 of 5 instances, respectively, without correlation between outcomes and antifungal minimum inhibitory concentrations. Furthermore, 5 of 7 patients treated with itraconazole cleared or had improvement at the last follow-up, and 2 of 7 were lost to follow-up or stopped treatment. Based on whole-genome sequencing analysis, US isolates formed a cluster distinct from Indian isolates. Conclusion and Relevance: The results of this case series suggest that disease severity, diagnostic delays, and lack of response to typically used doses and durations of antifungals for tinea were common in this primarily immunocompetent patient cohort with T indotineae, consistent with published data. Itraconazole was generally effective, and the acquisition of infection was likely in Bangladesh.

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.

Actualización en taxonomía, diagnóstico y tratamiento de las dermatofitosis / Update on taxonomy, diagnosis and treatment

Los dermatofitos son un grupo de hongos responsables de las dermatofitosis o tiñas, pudiendo afectar piel, uñas y pelo. En la actualidad están constituidos por los géneros Epidermophyton, Trichophyton, Microsporum, Arthroderma, Paraphyton, Lophophyton y Nannizzia. El examen microscópico directo y el cultivo en agar siguen siendo el estándar de oro para la identificación, sin embargo, en ocasiones se requiere de la biología molecular para poder corroborar una determinada especie. Dependiendo de la localización, del número de lesiones y de la extensión, el tratamiento de las dermatofitosis puede ser tópico o sistémico. Trichophyton indotineae y T tonsurans pueden expresar resistencia a la terbinafina y azoles, respectivamente.

Dermatophytes are a group of fungi responsible for dermatophytosis or ringworm, which can affect the skin, nails and hair. Currently, they are assembled by the genera Epidermophyton, Trichophyton, Microsporum, Arthroderma, Paraphyton, Lophophyton and Nannizzia. Direct microscopic examination and culture on agar remain the gold standard for identification, however, molecular biology is sometimes required to confirm a certain species. Depending on the location, the number of lesions and the extension, the treatment of dermatophytosis can be topical or systemic. Trichophyton indotineae and T tonsurans can express resistance to terbinafine and azoles, respectively.

Expert Panel Review of Skin and Hair Dermatophytoses in an Era of Antifungal Resistance.

Dermatophytoses are fungal infections of the skin, hair, and nails that affect approximately 25% of the global population. Occlusive clothing, living in a hot humid environment, poor hygiene, proximity to animals, and crowded living conditions are important risk factors. Dermatophyte infections are named for the anatomic area they infect, and include tinea corporis, cruris, capitis, barbae, faciei, pedis, and manuum. Tinea incognito describes steroid-modified tinea. In some patients, especially those who are immunosuppressed or who have a history of corticosteroid use, dermatophyte infections may spread to involve extensive skin areas, and, in rare cases, may extend to the dermis and hair follicle. Over the past decade, dermatophytoses cases not responding to standard of care therapy have been increasingly reported. These cases are especially prevalent in the Indian subcontinent, and Trichophyton indotineae has been identified as the causative species, generating concern regarding resistance to available antifungal therapies. Antifungal-resistant dermatophyte infections have been recently recognized in the United States. Antifungal resistance is now a global health concern. When feasible, mycological confirmation before starting treatment is considered best practice. To curb antifungal-resistant infections, it is necessary for physicians to maintain a high index of suspicion for resistant dermatophyte infections coupled with antifungal stewardship efforts. Furthermore, by forging partnerships with federal agencies, state and local public health agencies, professional societies, and academic institutions, dermatologists can lead efforts to prevent the spread of antifungal-resistant dermatophytes.

Widespread dermatophytosis in a healthy adolescent: the first report of multidrug-resistant Trichophyton indotineae infection in the UAE.

A multidrug-resistant dermatophyte species recently arose in India, first described as terbinafine-resistant Trichophyton interdigitale and soon given a separate name: T. indotineae. Thanks to its treatment recalcitrance, person-to-person spread, and frequent travel, before long it was identified in many countries on all continents. We describe here the case of a boy with widespread, extremely pruritic, inflammatory dermatophytosis affecting his face, neck, trunk, and extremities, unsuccessfully treated for months with oral terbinafine and fluconazole and a range of topical antimycotics. Qualitative polymerase chain reaction of skin scrapings from his lesions identified a T. interdigitale complex fungus, highly probably T. indotineae due to conspecificity and antifungal resistance. Oral itraconazole, administered over 8 weeks, cleared the infection. Because the patient had not traveled outside the United Arab Emirates for months before the infection became obvious, it must have been acquired from a local source.