The unprecedented epidemic-like scenario of dermatophytosis in India: III. Antifungal resistance and treatment options

Abstract

One of the canonical features of the current outbreak of dermatophytosis in India is its unresponsiveness to treatment in majority of cases. Though there appears to be discordance between in vivo and in vitro resistance, demonstration of in vitro resistance of dermatophytes to antifungals by antifungal susceptibility testing is essential as it may help in appropriate management. The practical problem in the interpretation of antifungal susceptibility testing is the absence of clinical breakpoints and epidemiologic cutoff values. In their absence, evaluation of the upper limit of a minimal inhibitory concentration of wild type isolates may be beneficial for managing dermatophytosis and monitoring the emergence of isolates with reduced susceptibility. In the current scenario, most of the cases are unresponsive to standard dosages and duration of treatment recommended until now. This has resulted in many ex-cathedra modalities of treatment that are being pursued without any evidence. There is an urgent need to carry out methodical research to develop an evidence base to formulate a rational management approach in the current scenario.

Trichophyton indotineae—An Emerging Pathogen Causing Recalcitrant Dermatophytoses in India and Worldwide—A Multidimensional Perspective

“…This may be due to in vitro resistance or at least reduced in vitro sensitivity of the respective dermatophytes [ 40 ]. The treatment failure of terbinafine, however, primarily affects Indian strains of T. indotineae [ 41 ]. It is not possible to properly estimate the approximate timing of the mutation(s) that occurred with the emergence of T. indotineae .…”

“…As mentioned earlier, a significant number of chronic recurrent dermatophytoses show no response to topical and oral terbinafine [ 41 ]. T. indotineae is predominantly resistant to terbinafine in vitro ( Figure 9 ).…”

“…The drug of choice for treating dermatophytosis caused by this pathogen is itraconazole [ 39 ]. The dosage is 100 mg itraconazole twice daily for 4 to 8 weeks, and in some individuals even up to 12 weeks [ 41 ]. Recently, itraconazole manufactured with SUBA (super bioavailability) technology has been found to be efficacious [ 63 ] in 50 mg twice-a-day preparation, for the same duration as for conventional itraconazole.…”

Detection of emerging genotypes in Trichophyton mentagrophytes species complex: A proposal for handling biodiversity in dermatophytes

“…Several species of dermatophytes are involved in this new problem, including T. rubrum ( Shankarnarayan et al, 2020 ) and particularly species of the T. mentagrophytes complex ( Singh et al, 2019 ). Inappropriate use of antifungal creams with corticosteroids has been hypothesized to be a main reason for this emergence ( Verma et al, 2021 ).…”

Erythrodermic dermatophytosis: an alarming consequence of steroid abuse and misuse. A multicentre prospective study from India

“…Some of the pivotal steps include rectification of the underlying hypothalamic-pituitary-adrenal axis suppression (especially in patients who have received parenteral steroids for a long duration), referral to endocrinology specialists where necessary, complete avoidance of systemic and topical corticosteroids, symptomatic relief with antihistamines and topical and oral antifungals, addressing the underlying comorbid conditions, and treating any contacts. 6 In conclusion, we describe a case series on erythrodermic dermatophytosis as a harrowing sequelae of unwarranted prescription of corticosteroid medications by unqualified practitioners. In patients presenting with erythroderma, dermatophytosis should be considered as a differential diagnosis.…”