Background: Exosomes are small extracellular vesicles with potential roles in modulating the hair growth cycle and are an emerging therapy for patients with alopecia. In recent years, researchers have made significant progress in deciphering the network of cellular interactions and signaling pathways mediated by the transfer of exosomes. This has opened the door to a wide range of potential therapeutic applications with an increasing focus on its application in precision medicine.Aim: To evaluate current published evidence, both preclinical and clinical, on the use of exosomes for hair restoration.Methods: In January 2023, a systematic search was conducted using PubMed, Embase, and the Cochrane Library. Records were identified, screened, and assessed for eligibility as per the PRISMA guideline.Results: We identified 16 studies (15 preclinical and 1 clinical) showing varying degrees of efficacy using exosomes derived from sources including adipose‐derived stem cells (ADSCs) and dermal papilla cells (DPCs). Applications of exosomes isolated from ADSCs (ADSC‐Exo) and DPCs have shown early promising results in preclinical studies corroborated by results obtained from different model systems. Topical ADSC‐Exo has been tried successfully in 39 androgenetic alopecia patients demonstrating significant increases in hair density and thickness. No significant adverse reactions associated with exosome treatment have been reported thus far.Conclusions: Although current clinical evidence supporting the use of exosome treatment is limited, there is a growing body of evidence suggesting its therapeutic potential. Further studies are warranted to define its mechanism of action, optimize its delivery and efficacy, and to address important safety concerns.

Background/Objectives: Terbinafine has been the gold standard for the management of superficial fungal infections. The etiological agent generally is Trichophyton rubrum (T. rubrum); however, there has been increased reporting of a new terbinafine-resistant strain of the T. mentagrophytes complex (T. mentagrophytes ITS genotype VIII otherwise known as T. indotineae). Here, we review the epidemiology, clinical features, diagnosis, and treatment of T. rubrum and T. indotineae infections. Methods: We conducted a systematic literature search using PubMed, Embase (Ovid), and Web of Science, resulting in 83 qualified studies with data summarized for clinical features, antifungal susceptibility, and terbinafine resistance mechanisms and mutations. Results: Dermatophytosis is most commonly caused by T. rubrum; however, in certain parts of the world, especially in the Indian subcontinent, T. indotineae infections have been reported more frequently. The majority of T. rubrum isolates remain susceptible to terbinafine (over 60% of isolates show MIC₅₀ and MIC₉₀ < 0.5 µg/mL). In contrast, for T. indotineae, 30% of isolates exhibit MIC₅₀ ≥ 0.5 µg/mL and 80% exhibit MIC₉₀ ≥ 0.5 µg/mL. Frequently detected squalene epoxidase (SQLE) mutations in T. rubrum are Phe397Leu/Ile (41.6%) and Leu393Phe (20.8%); in T. indotineae, these include Phe397Leu (33.0%) and Ala448Thr (24.5%). Other potential terbinafine resistance mechanisms in T. rubrum and T. indotineae are discussed. Conclusions: T. rubrum generally remain susceptible in vitro to terbinafine in contrast to T. indotineae. The essential components of an effective antifungal stewardship emphasize accurate clinical and laboratory diagnosis, susceptibility testing, and appropriate antifungal therapy selection with a multidisciplinary approach.

There has been a recent shift in the epidemiology of superficial fungal infections (tinea, dermatophytosis, dermatomycoses). Trichophyton indotineae is an emerging dermatophyte species of significant global concern for its contagious nature and antifungal drug resistance. This scoping review includes available clinical and laboratory assessments of T. indotineae to provide a comprehensive up‐to‐date overview of its epidemiology, clinical manifestations, diagnostic approaches, antifungal susceptibility patterns, resistance mechanisms and management strategies. We discuss T. indotineae resistance against standard and newer antifungals (terbinafine, griseofulvin and triazoles including fluconazole, itraconazole, voriconazole and posaconazole). In particular, the terbinafine susceptibility profile of T. indotineae can be linked to squalene epoxidase ( SQLE ) single‐nucleotide variations. For diagnosis, it is not possible to separate T. indotinea e from other members of the T. mentagrophytes complex ( T. mentagrophytes and T. interdigitale ) without access to molecular diagnostic methods. So, in patients presenting with extensive dermatophytoses, with a history of treatment resistance and/or recent travel, molecular diagnosis to confirm T. indotineae infection should be considered. Healthcare providers often face challenges in choosing between terbinafine and itraconazole treatments. While the use of terbinafine is limited due to resistance, itraconazole is hindered by erratic absorption, possible drug interactions and side effects as well as resistance in some cases. Newer treatments being investigated include super‐bioavailable itraconazole, third‐generation triazoles (voriconazole, posaconazole) and topical‐oral combination regimens. The need for improved diagnostic accessibility, judicious antifungal prescribing, and implementing an effective antifungal stewardship program are highlighted.

Background: Onychomycosis is a chronic nail disorder commonly seen by healthcare providers; toenail involvement in particular presents a treatment challenge.Objective: To provide an updated estimate on the prevalence of toenail onychomycosis.Methods: We conducted a literature search using PubMed, Embase and Web of Science. Studies reporting mycology‐confirmed diagnoses were included and stratified into (a) populations‐based studies, and studies that included (b) clinically un‐suspected and (c) clinically suspected patients.Results: A total of 108 studies were included. Based on studies that examined clinically un‐suspected patients (i.e., with or without clinical features suggestive of onychomycosis), the pooled prevalence rate of toenail onychomycosis caused by dermatophytes was 4% (95% CI: 3–5) among the general population; special populations with a heightened risk include knee osteoarthritis patients (RR: 14.6 [95% CI: 13.0–16.5]), chronic venous disease patients (RR: 5.6 [95% CI: 3.7–8.1]), renal transplant patients (RR: 4.7 [95% CI: 3.3–6.5]), geriatric patients (RR: 4.7 [95% CI: 4.4–4.9]), HIV‐positive patients (RR: 3.7 [95% CI: 2.9–4.7]), lupus erythematosus patients (RR: 3.1 [95% CI: 1.2–6.3]), diabetic patients (RR: 2.8 [95% CI: 2.4–3.3]) and hemodialysis patients (RR: 2.8 [95% CI: 1.9–4.0]). The prevalence of onychomycosis in clinically suspected patients was significantly higher likely due to sampling bias. A high degree of variability was found in a limited number of population‐based studies indicating that certain pockets of the population may be more predisposed to onychomycosis. The diagnosis of non‐dermatophyte mould onychomycosis requires repeat sampling to rule out contaminants or commensal organisms; a significant difference was found between studies that performed single sampling versus repeat sampling. The advent of PCR diagnosis results in improved detection rates for dermatophytes compared to culture.Conclusion: Onychomycosis is an underrecognized healthcare burden. Further population‐based studies using standardized PCR methods are warranted.

Dermatophytes are commonly encountered pathogens in clinical practice causing superficial infections of the skin, hair, and nails. These pathogens are often found on animals such as livestock (e.g., cattle, rabbits) and pets (e.g., cats, hedgehogs) that can lead to spillover infections in human populations. Here, we reviewed published reports (2009–2024) of dermatophyte infections in animals and in humans with a history of animal contact. A literature search was completed in October 2024 using PubMed, Embase (Ovid), and Web of Science (Core Collection), which identified 250 articles. Generally, dermatophytes tend to infect younger animals with long hair and exhibit a species-specific host range. Microsporum canis was the most commonly reported species—linked to cats—that can cause tinea capitis, especially concerning the development of kerion in children. Trichophyton verrucosum is strongly associated with cattle. The Trichophyton mentagrophytes complex shows a diverse range of animal hosts, with rabbits being most frequently reported; however, T. mentagrophytes var. erinacei is almost exclusively isolated from hedgehogs, and T. mentagrophytes var. benhamiae is more commonly found on rodents (e.g., guinea pigs). Lastly, the geophilic Nannizia gypsea has been isolated from both dogs and cats. Managing dermatophyte zoonoses is an ongoing challenge, as healthcare providers may empirically treat with corticosteroids or antibacterial agents due to its atypical inflammatory appearance. Evidence of in vitro resistance against griseofulvin and fluconazole has been documented in multiple zoonotic dermatophyte species. Resistance development against terbinafine and itraconazole is also a possibility, although the number of reports is scarce. Under the principles of the One Health approach, research on human fungal diseases should take animal and environmental factors into account. A renewed call for increased testing efforts is warranted.