The CARDS (China Antifungal Resistance Dermatophytes Surveillance network Study) report, published by Kong et al.1 in this issue of JEADV, serves as a timely and crucial epidemiological warning. This systematic evaluation of antifungal susceptibility in the Trichophyton mentagrophytes species complex (TMSC) in China confirms emerging global public health concerns. Lineage number VIII, also known as Trichophyton indotineae and initially surging in the Indian subcontinent,2 epitomizes an apparent adaptive shift to high levels of virulence and TBF-resistance, driven by drug selection pressure. Now showing community transmission reported across Asia, Europe and the United States,3 this clone constitutes a genuine global threat. First Chinese reports of the lineage were in immigrants from India,4 but the CARDS report indicates that it is now established and spreading more widely. Recently, genotype VII also emerges by host-to-host transmission.5 The ancestral species T. mentagrophytes was long thought to be zoophilic.6 The host shift to humans is a classic example of dermatophyte evolution. With human-to-human transmission, the widespread inappropriate use of antifungal creams compounded with steroids globally has created immense selection pressure. Dermatophytes successfully evolve into TBF-resistant clones such as T. indotineae by acquiring SQLE gene mutation Phe397Leu. This functional transformation allows strains to survive conventional treatment and dominate the ecological niche within the human population. Accelerated global travel facilitates the geographic spread of resistant clones, rapidly establishing new transmission cycles across continents and escalating dermatophytosis from an endemic problem to an international public health crisis. The significance of the study by Kong et al. lies in its robust data, grounded in molecular diagnosis and standardized EUCAST susceptibility testing. Although T. indotineae only accounted for 7.83% of the total samples, its danger should not be underestimated. The most critical finding is that all isolated T. indotineae strains demonstrated resistance to terbinafine, with the majority carrying the signature SQLE mutation, consistent with its status as a global resistant clone. Even more alarming is the observed increase in minimum inhibitory concentrations (MICs) for several alternative agents, including miconazole and griseofulvin, suggesting a trend towards Multi-Drug Resistance (MDR). These findings present an immediate and urgent MDR crisis for clinical practice. Terbinafine and azoles represent the empirical first-line therapy for dermatophytosis in China and globally. Clinicians must maintain a high index of suspicion for resistant strains when patients experience high treatment failure rates or when the disease progresses to chronic, recalcitrant tinea corporis or cruris. The epidemiological data from CARDS—particularly the difference between the susceptible T. mentagrophytes prevalence in Central China and the T. indotineae prevalence in Eastern China—can guide clinicians in more precisely assessing risk based on a patient's geography and travel history. The study also points the way towards treatment alternatives. All strains, including resistant T. indotineae, maintained high susceptibility to luliconazole and amorolfine. This provides powerful topical or adjunctive therapeutic options for recalcitrant cases. In summary, the CARDS study is a forward-looking surveillance paradigm that not only reveals the status of ARD in China but also serves as a global wake-up call. In the context of globalization, antifungal resistance knows no borders. The dermatology community urgently needs to (1) enhance genotype-guided diagnosis for recalcitrant dermatophytosis; (2) encourage the use of non-terbinafine agents such as luliconazole as alternative therapies for resistant cases; and (3) establish unified global ARD surveillance networks to rapidly track and contain newly emerging resistant strains such as T. indotineae; similar initiatives have also been undertaken in Europe.7, 8 We must regard the management of dermatophytosis as a critical, ongoing global public health concern. None declared. Data sharing is not applicable to this article as no new data were created or analysed in this study.
Zhou et al. (Tue,) studied this question.