Is Antifungal Resistance a Cause for Treatment Failure in Dermatophytosis: A Study Focused on Tinea Corporis and Cruris from a Tertiary Centre?

Design, synthesis, docking studies and bioactivity evaluation of 1,2,3-triazole eugenol derivatives

Aim: The design, synthesis, docking studies and evaluation of the in vitro antifungal and cytotoxic properties of eugenol (EUG) containing 1,2,3-triazole derivatives are reported. Most of the derivatives have not been reported.Materials & methods: The EUG derivatives were synthesized, molecular docked and tested for their antifungal activity.Results: The compounds showed potent antifungal activity against Trichophyton rubrum, associated with dermatophytosis. Compounds 2a and 2i exhibited promising results, with 2a being four-times more potent than EUG. The binding mode prediction was similar to itraconazole in the lanosterol-14-α-demethylase wild-type and G73E mutant binding sites. Additionally, the pharmacokinetic profile prediction suggests good gastrointestinal absorption and potential oral administration.Conclusion: Compound 2a is a promising antifungal agent against dermatophytosis caused by T. rubrum.

Prolonged treatment of dermatophytosis caused by Trichophyton indotinea with terbinafine or itraconazole impacts better outcomes irrespective of mutation in the squalene epoxidase gene

BACKGROUND

Over the past decades, the increasing incidence of recurrent dermatophytosis associated with terbinafine-resistant Trichophyton has posed a serious challenge in management of dermatophytosis. Independent reports of failure of treatment and high minimum inhibitory concentrations (MIC) of antifungals are available, but data correlating MIC and clinical outcomes is still sparse. Therefore, the present study was conducted to evaluate the outcomes of systemic treatment of dermatophytosis and its correlation with MIC of the etiological agents isolated from such patients.

METHODS

Retrospective analysis of 587 consecutive patients with dermatophytosis was done from March 2017 to March 2019. Demographic and clinical details of the patients were noted, along with the results of direct microscopy and fungal culture. The isolates were identified by sequencing the internal transcribed spacer region of rDNA. Antifungal susceptibility testing was performed following the CLSI M38 protocol. Mutation in the squalene epoxidase (SE) gene was detected by DNA sequencing and ARMS-PCR. Based on the culture-positivity and prescribed systemic antifungal, patients were categorised into Group I culture-positive cases treated with systemic terbinafine and Group II culture-positive cases treated with systemic itraconazole, each for a total period of 12 weeks.

RESULTS

In the present study, 477 (81.39%) were culture-positive; however, 12 weeks follow-up was available for 294 patients (Group I-157 and Group II-137) who were included for statistical analysis. In both groups [Group I-37/63 (51.4%) and Group II-14/54 (58.3%)], a better cure rate was observed if the initiation of therapy was performed within <6 months of illness. Treatment outcome revealed that if therapy was extended for 8-12 weeks, the odds of cure rate are significantly better (p < .001) with either itraconazole (Odd Ratio-15.5) or terbinafine (Odd Ratio-4.34). Higher MICs for terbinafine were noted in 41 cases (cured-18 and uncured-23) in Group I and 39 cases (cured-16 and uncured-23) in Group II. From cured (Group I-17/18; 94.4% and Group II-14/16; 87.5%) and uncured (Group I-20/23; 86.9% and Group II-21/23; 91.3%) cases had F397L mutation in the SE gene. No significant difference in cure rate was observed in patients with Trichophyton spp. having terbinafine MIC ≥ 1or <1 μg/mL (Group I-p = .712 and Group II-p = .69).

CONCLUSION

This study revealed that prolonging terbinafine or itraconazole therapy for beyond 8 weeks rather than the standard 4 weeks significantly increases the cure rate. Moreover, no correlation has been observed between antifungal susceptibility and clinical outcomes. The MIC remains the primary parameter for defining antifungal activity and predicting the potency of antifungal agents against specific fungi. However, predicting therapeutic success based solely on the MIC of a fungal strain is not always reliable, as studies have shown a poor correlation between in vitro data and in vivo outcomes. To address this issue, further correlation of antifungal susceptibility testing (AFST) data with clinical outcomes and therapeutic drug monitoring is needed. It also highlights that initiation of the treatment within <6 months of illness increases cure rates and reduces recurrence. Extensive research is warranted to establish a better treatment regime for dermatophytosis.

Bioinformatics-Driven mRNA-Based Vaccine Design for Controlling Tinea Cruris Induced by Trichophyton rubrum

Tinea cruris, a dermatophyte fungal infection predominantly caused by Trichophyton rubrum and Epidermophyton floccosum, primarily affects the groin, pubic region, and adjacent thigh. Its recurrence is frequent, attributable to repeated fungal infections in susceptible individuals, especially those with onychomycosis or tinea pedis, which act as reservoirs for dermatophytes. Given the persistent nature of tinea cruris, vaccination emerges as a promising strategy for fungal infection management, offering targeted, durable protection against various fungal species. Vaccines stimulate both humoral and cell-mediated immunity and are administered prophylactically to prevent infections while minimizing the risk of antifungal resistance development. Developing fungal vaccines is challenging due to the thick fungal cell wall, similarities between fungal and human cells, antigenic variation, and evolutionary resemblance to animals, complicating non-toxic target identification and T-cell response variability. No prior research has shown an mRNA vaccine for T. rubrum. Hence, this study proposes a novel mRNA-based vaccine for tinea cruris, potentially offering long-term immunity and reducing reliance on antifungal medications. This study explores the complete proteome of T. rubrum, identifying potential protein candidates for vaccine development through reverse vaccinology. Immunogenic epitopes from these candidates were mapped and integrated into multitope vaccines and reverse translated to construct mRNA vaccines. Then, the mRNA was translated and computationally assessed for physicochemical, chemical, and immunological attributes. Notably, 1,3-beta-glucanosyltransferase, CFEM domain-containing protein, cell wall galactomannoprotein, and LysM domain-containing protein emerged as promising vaccine targets. Antigenic, immunogenic, non-toxic, and non-allergenic cytotoxic T lymphocyte, helper T lymphocyte, and B lymphocyte epitopes were selected and linked with appropriate linkers and Toll-like receptor (TLR) agonist adjuvants to formulate vaccine candidates targeting T. rubrum. The protein-based vaccines underwent reverse translation to construct the mRNA vaccines, which, after inoculation, were translated again by host ribosomes to work as potential components for triggering the immune response. After that, molecular docking, normal mode analysis, and molecular dynamic simulation confirmed strong binding affinities and stable complexes between vaccines and TLR receptors. Furthermore, immune simulations of vaccines with and without adjuvant demonstrated activation of immune responses, evidenced by elevated levels of IgG1, IgG2, IgM antibodies, cytokines, and interleukins. There was no significant change in antibody production between vaccines with and without adjuvants, but adjuvants are crucial for activating the innate immune response via TLRs. Although mRNA vaccines hold promise against fungal infections, further research is essential to assess their safety and efficacy. Experimental validation is crucial for evaluating their immunogenicity, effectiveness, and safety.

Tinea Incognito: Challenges in Diagnosis and Management

Tinea incognito is a dermatophyte infection with atypical features, due to the use of topical or systemic steroids or other immunosuppressive medications. Delayed diagnosis, spread of the infection to critical body surfaces, resistance to antifungal drugs, and increased costs due to prolonged hospitalization and multiple treatment regimens often complicate tinea incognito. It can affect individuals of all ages and genders, but it is more common in children. Atypical clinical appearance often necessitates differentiation from other diseases such as eczema, seborrheic dermatitis, lupus erythematosus, psoriasis, or other non-fungal skin conditions. The treatment of tinea incognito usually involves discontinuation of topical steroids or other immunosuppressive medications. Preventive measures and management of the underlying fungal infection are necessary and can be achieved with antifungal drugs. Patients should wear loose cotton clothes, use boiling water for laundry, and iron their clothing before wearing them. Additionally, they should avoid sharing bed linens, towels, clothes, and shoes. This review aims to raise awareness of tinea incognito among health practitioners, provide tips for detecting the disorder, include it in the differentials, and evaluate the available diagnostic procedures.

Clinical Use of Super-Bioavailable Itraconazole for the Management of Dermatophytosis: Consensus Statement by Dermatologists from India via the Modified Delphi Technique

Super-bioavailable itraconazole (SB ITZ) overcomes the limitations of conventional itraconazole (CITZ) such as interindividual variability and reduced bioavailability. It has been approved for systemic mycoses in Australia and Europe as 50 mg and the USA as 65 mg and in India as 50 mg, 65 mg, 100 mg, and 130 mg. However, data on the ideal dose and duration of SB ITZ treatment in managing dermatophytosis are insufficient. This consensus discusses the suitability, dosage, duration of treatment, and relevance of using SB ITZ in managing dermatophytosis in different clinical scenarios. Sixteen dermatologists (>15 years of experience in the field and ≥2 years clinical experience with SB ITZ), formed the expert panel. A modified Delphi technique was employed, and a consensus was reached if the concordance in response was >75%. A total of 26 consensus statements were developed. The preferred dose of SB ITZ is 130 mg once daily and if not tolerated, 65 mg twice daily. The preferred duration for treating naïve dermatophytosis is 4-6 weeks and that for recalcitrant dermatophytosis is 6-8 weeks. Moreover, cure rates for dermatophytosis are a little better with SB ITZ than with CITZ with a similar safety profile as of CITZ. Better patient compliance and efficacy are associated with SB ITZ than with CITZ, even in patients with comorbidities and special needs such as patients with diabetes, extensive lesions, corticosteroid abuse, adolescents, and those on multiple drugs. Expert clinicians reported that the overall clinical experience with SB ITZ was better than that with CITZ.

Efficacy of Terbinafine and Itraconazole Combination Therapy Versus Terbinafine or Itraconazole Monotherapy in the Management of Fungal Diseases: A Systematic Review and Meta-Analysis

Fungal infections constitute a common dermatological illness rampant in underdeveloped countries. Combination drug therapy is becoming increasingly well-established owing to drug resistance because of monotherapy. Different studies have been conducted previously to compare the medical regimens for the treatment of fungal infections. However, there is insufficient research on the difference in cure rates and recurrence rates with each regimen. To the best of our knowledge, this meta-analysis is the first to compare the effect of the most widely used oral antifungal medications and their combination usage. A meta-analysis of randomized controlled trials (RCTs) assesses the efficacy of terbinafine or itraconazole monotherapy versus combination therapy in fungal diseases. We queried PubMed and Cochrane Central from their inception to April 2022 for published studies, RCTs, and observational studies without any language restriction that compared itraconazole and terbinafine combination therapy with monotherapy in patients with fungal infections. The results from the studies were presented as risk ratios (RRs) with 95% confidence intervals (CIs) and were pooled using a random-effects model, and a p-value of ≤0.05 was considered significant for the analysis. Endpoints of interest included cure rates and recurrence rates. Cure rates were increased significantly for combination therapy compared to terbinafine monotherapy (RR=2.01 (1.37, 2.94); p=0.0003; I2=67%). On sensitivity analysis, a significant association was observed between combination therapy and itraconazole monotherapy in terms of cure rates (RR=1.91 (1.41, 2.57); p<0.0001; I2=0%) and recurrence rates (RR=0.08 (0.02, 0.44); p=0.003; I2=0%). The findings of this meta-analysis suggest that itraconazole and terbinafine combination therapy has a better cure rate when compared to terbinafine monotherapy.

A Clinical-Mycological Study of Dermatophytosis in Western India with Focus on Antifungal Drug Resistance as a Factor in Recalcitrance

Background

Dermatophytosis have assumed epidemic proportions in India. Antifungal drug resistance solely cannot explain disease magnitude and changing epidemiology.

Objectives

Aim of this study was to analyse clinical-mycological aspects of dermatophytosis, and estimate contribution of drug resistance in clinical recalcitrance.

Methods

This single-centre observational, cross-sectional, descriptive study was done in tertiary centre of western India after ethical approval, enrolling dermatophytosis patients of all ages and sex. After history and examination, KOH mount and culture in modified SDA medium was done. Culture positive isolates were subjected to E-strip antifungal susceptibility method to test MIC for Terbinafine, Itraconazole, Fluconazole and Griseofulvin.

Results

Total 300 patients were included, with mean age of 33.83±27.5 years and male-to-female ratio of 1.22:1; tinea corporis et cruris being commonest, 39.33% (n=118). Only 11.67% (n=35) were treatment naïve, having classical annular morphology. History of topical steroid abuse was found in 81.67% (n=245), with pseudoimbricate lesions in 70.61% (n=173). 86.67% (n=260) had KOH positivity while 83.33% (n=250) had culture positivity: Trichophyton mentagrophytes 45.6% (n=114), followed by Trichophyton rubrum in 34.4% (n=86). A total of 265 patients fit into definition of recalcitrance, from which 12.45%, i.e., 33 isolates showed in-vitro fluconazole resistance. 14.33% (n=43) cases were chronic, 37% (n=111) persistent, 46% (n=138) recurrent while 17% (n=51) had relapse in their disease course. Steroid abuse was the commonest denominator.

Conclusion

Role of antifungal resistance in recalcitrant dermatophytosis remains debatable. Stopping steroid abuse, which is often the commonest culprit, with adherence to standard antifungal therapy remains the paradigm in management.

Species Distribution and Antifungal Susceptibility Profile of Dermatophytes from a Tertiary Care Centre in North India

Objective Dermatophytoses, one of the most ancient diseases, is becoming a menace in recent times. This has made the knowledge of antifungal susceptibility a priority in today's times.

Material and Methods This is a prospective study conducted over 18 months including all dermatophytes isolated during the period. Dermatophytes were identified by routine phenotypic methods. Antifungal susceptibility testing was performed for griseofulvin, terbinafine, and itraconazole as per the Clinical Laboratory Standard Institute M38 A2, and minimum inhibitory concentrations (MICs) were read after 5 days.

Results Patient details and associated risk factors were recorded. Fixed dose combinations with steroids were associated with 79.3% (46 out of 58) of patients with dermatophytosis of skin. Among the 72 dermatophytes isolated during the study period, 58 (80.5%) were isolated from skin scrapings and 14 (19.4%) from nail samples. Tinea corporis with cruris was the most common presentation. The most common dermatophyte isolated from skin scrapings was Trichophyton mentagrophytes complex (70.6%, 41 out of 58), while from nail samples it was Trichophyton rubrum complex (78.57%, 11 out of 14). Based on the MIC50 and MIC90 results, itraconazole showed the lowest MICs, followed by terbinafine and then griseofulvin.

Conclusion With the changing epidemiology of species distribution and antifungal resistance, there is a need for continuous surveillance of these parameters of dermatophytes.

Real World Analysis of Response Rate and Efficacy of Oral Ketoconazole in Patients with Recalcitrant Tinea Corporis and Cruris

Recalcitrant dermatophytosis has had an alarming rise in India with concomitant decreased effectiveness of conventional antifungal agents. This has prompted the use of second-line agents for treatment. In this retrospective study, we aimed to analyze the response rate, efficacy, relapse rate, and side effects of oral ketoconazole (KZ) in the treatment of recalcitrant tinea corporis and cruris. Institutional records were reviewed for patients presenting with tinea cruris or corporis who had failed treatment with conventional antifungal drugs and treated with oral KZ. Potassium hydroxide (KOH) findings, culture reports, and response to treatment was noted based on the percentage improvement in lesions and reduction in itching compared with baseline. Fourty-three patients (mean age 31.3 years) with tinea corporis/cruris who had taken prior treatment with antifungals were recruited in the study. KOH mount and culture were positive in 76.7% patients. Trichophyton mentagrophytes was the commonest species, isolated in 62.8% of patients. Ketoconazole showed the lowest minimum inhibitory concentration on antifungal susceptibility tests with various antifungals. With a dose of 400 mg daily, 67.4% of patients were cured of disease with mean duration of 9.4 weeks. Patients having less than 40% clearance at 2 weeks had a 68.9% less probability of getting cured of disease. Of the 29 patients cured, 37.9% relapsed because of various predisposing factors. Two patients developed increase in liver enzymes on treatment. Our analysis suggests that KZ can be used as alternative drug in cases with failure to conventional antifungal drugs. Though there are relapses, these can be partially explained by various predisposing factors that support fungal survival and transmission.

Topical steroid containing combinations: Burden of adverse effects and why the recent regulatory action may not be enough

OBJECTIVES AND METHODS

In September 2018, the government of India banned 328 fixed dose combinations (FDCs), 24 of which are combinations containing topical steroids. To assess what impact can be expected from this regulatory action, we analyzed reports of adverse drug events due to topical corticosteroids at a hospital-based pharmacovigilance center between January 2017 and August 2018.

RESULTS

Among 34 different steroid-containing FDCs responsible for 485 reports of ADEs with topical steroids, only three preparations, accounting for 50.10% of ADEs, come under the umbrella of the recent ban. Clobetasone propionate (68.87%) and betamethasone (28.45%) were the corticosteroids most frequently associated with adverse events. Most of the steroid preparations (87.84%) had been bought without a prescription for the treatment of dermatophytoses (76.70%). Males (77.73%) were predominantly affected, and nearly half (47.43%) of the patients were between 21 and 30 years of age. Skin atrophy (50.10%), striae (25.54%), and hypopigmentation (19.79%) were the major ADEs.

CONCLUSION

Nearly half of the cutaneous adverse effects were due to topical steroid combinations which are still widely available over the counter.

Clinico-Mycological Profile of Treatment-Naïve, Chronic, Recurrent and Steroid-Modified Dermatophytosis at a Tertiary Care Centre in Eastern India: An Institution-Based Cross-SectionalStudy

Background:

Dermatophytosis has recently emerged as a major public health problem in the Indian subcontinent, most cases becoming chronic and recurrent.

Aims:

Assessing the clinico-epidemiologic and mycologic profile of treatment naïve, chronic, recurrent and steroid-modified dermatophytosis.

Materials and Methods:

We conducted across-sectional study involving 111 cases of dermatophytosis. Detailed epidemiology, clinical parameters, treatment history and other host factors were assessed along with scraping for potassium hydroxide (KOH) and fungal culture.

Results:

Among 111 patients,(F: M 1.7:1; mean age 44.4 ± 18.2 years), 51.4% were treatment naïve, while 34.2% and 14.4% presented with chronic and recurrent tinea respectively. Family history and sharing of fomites among infected family members was commoner in the latter groups (P = 0.001). Topical steroid application was reported in 49.5%, however only 7.2% presented with steroid modified tinea. Tinea corporis et cruris (41.4%) was the predominant clinical type followed by tinea corporis (34.2%) and tinea cruris (27.9%). KOH mount and culture were positive in 62.2% and 39.6% cases respectively; commonest isolates being Trichophyton rubrum, and Trichophyton mentagrophytes complex in 15.3% cases each. Trichophyton rubrum was the commonest etiology for treatment naïve and recurrent cases, while Trichophyton mentagrophytes was the commonest isolate from chronic and steroid-modified cases (P = 0.0003). Interestingly, T.mentagrophytes complex and T. rubrum were the commonest causes of tinea corporis and tinea cruris respectively (P = 0.07).

Conclusion:

Trichophyton rubrum was the commonest organism in treatment naïve and recurrent cases, while Trichophyton mentagrophytes complex accounted for most cases of chronic and steroid modified tinea. The difference in predominant species seems to be a major contributory factor for chronicity and recurrence. However, several host factors like topical steroid use and sharing of fomites also play additional roles.

Antifungal Combinations in Dermatophytes

Dermatophytes are the most common cause of fungal infections worldwide, affecting millions of people annually. The emergence of resistance among dermatophytes along with the availability of antifungal susceptibility procedures suitable for testing antifungal agents against this group of fungi make the combinatorial approach particularly interesting to be investigated. Therefore, we reviewed the scientific literature concerning the antifungal combinations against dermatophytes. A literature search on the subject performed in PubMed yielded 68 publications: 37 articles referring to in vitro studies and 31 articles referring to case reports or clinical studies. In vitro studies involved over 400 clinical isolates of dermatophytes (69% Trichophyton spp., 29% Microsporum spp., and 2% Epidermophyton floccosum). Combinations included two antifungal agents or an antifungal agent plus another chemical compound including plant extracts or essential oils, calcineurin inhibitors, peptides, disinfectant agents, and others. In general, drug combinations yielded variable results spanning from synergism to indifference. Antagonism was rarely seen. In over 700 patients with documented dermatophyte infections, an antifungal combination approach could be evaluated. The most frequent combination included a systemic antifungal agent administered orally (i.e., terbinafine, griseofulvin, or azole-mainly itraconazole) plus a topical medication (i.e., azole, terbinafine, ciclopirox, amorolfine) for several weeks. Clinical results indicate that association of antifungal agents is effective, and it might be useful to accelerate the clinical and microbiological healing of a superficial infection. Antifungal combinations in dermatophytes have gained considerable scientific interest over the years and, in consideration of the interesting results available so far, it is desirable to continue the research in this field.

Chronic Dermatophytosis: Clinico-Mycological Determinants and Antifungal Susceptibility Pattern

Background:

Recent years have witnessed a dramatic increase in chronic unresponsive dermatophytosis. A study was conducted to quantify the proportion of patients with chronic dermatophytosis and to determine the clinico-mycological predictors of chronicity including antifungal susceptibility.

Methods:

Hospital-based cross-sectional study design was adopted. Four hundred and twenty-five patients were studied. The outcome variable was chronic dermatophytosis and the determinants were clinico-mycological characteristics. Chi-square and odds ratio (OR) with 95% confidence interval (CI) were calculated.

Results:

Chronic dermatophytosis was seen in 29.4%. Past history of dermatophytosis, OR 0.44 (95% CI 0.28–0.68); family history of dermatophytosis, OR 1.66 (95% CI 1.06–2.56); HIV infection, OR 9.88 (95% CI 1.09–89.33); treatment with topical antifungals, OR 2.4 (95% CI 1.5–3.9); systemic antifungals, OR 3.9 (95% CI 2.5–6.1); topical steroids, OR 2.02 (95% CI 1.25–3.25); multiple-site infection, OR 1.97 (95% CI 1.24–3.13); and tinea unguium, OR 6.52 (95% CI 2.89–14.7) were the significant determinants. Trichophyton mentagrophytes (73.6%) was the most common isolate followed by Trichophyton rubrum and Microsporum gypseum (13.2%) each. A percentage of 77.4 of the isolates were resistant—73.6% isolates to terbinafine and 3.8% isolates to fluconazole. None of the isolates were resistant to itraconazole.

Conclusion:

Significant determinants were host-related factors. Thorough history taking, patient examination, and education can improve the present scenario. Microbiological resistance was not a significant predictor. High proportion of resistant strains should be an eye opener. Developing and adopting a standard uniform treatment protocol throughout the country should be the need of the hour.

Evaluation of efficacy and safety of oral voriconazole in the management of recalcitrant and recurrent dermatophytosis

BACKGROUND

Dermatophytosis is a worldwide public health problem, affecting > 25% of the world's population. There has been a rampant increase in the resistant, recurrent dermatophytosis in the past few years, especially in India. Azole resistance in dermatophytes has been reported to be as high as 19% worldwide, hence evaluating the efficacy and safety of a newer oral antifungal is important.

AIM

To evaluate the efficacy and safety of oral voriconazole in the management of recalcitrant and recurrent dermatophytosis.

METHODS

Patients with extensive, recurring and resistant dermatophytosis. The clinical diagnosis was confirmed by potassium hydroxide staining. Patients were given a 2-week course of oral voriconazole, administered as 800 mg on Day 1, followed by two daily doses of 200 mg (total 400 mg/day) for the remaining 13 days. The patients were followed up in Week 2 to assess response and in Week 6 to assess recurrence. Patients were monitored for any adverse effects (AEs).

RESULTS

In total, 40 patients completed the study. Complete clearance was seen in 90% and 75% at Weeks 2 and 6, respectively. By the end of Week 6, eight patients (20%) had partial improvement of disease without complete clearance and only 5% had recurrence. No AEs were recorded during the treatment course.

CONCLUSION

Voriconazole, a novel oral antifungal that can be used for treatment of recurrent and resistant dermatophytosis, has a good efficacy and safety profile with a very low rate of recurrence.

Etiological prevalence and antifungal sensitivity patterns of dermatophytosis in India - A multicentric study

BACKGROUND

The prevalence of dermatophytes varies with season, geographical area, socio-economic factors and effective management strategies.

AIMS

The aim of the study was to assess the prevalence of pathogenic dermatophytes, clinical types of dermatophyte fungal infection, and in vitro antifungal drug susceptibility testing against dermatophytes.

METHODS

Three hundred and ninety five patients with dermatophytosis were enrolled from five cities (Mumbai, Delhi, Lucknow, Kolkata and Hyderabad) across India. All patients were subjected to clinical examination and investigations, including potassium hydroxide microscopy, fungal culture and antifungal drug susceptibility testing.

RESULTS

Trichophyton rubrum was the most common species identified (68.4%), followed by T. mentagrophytes (29.3%). Within species, T. mentagrophytes was prevalent in humid environmental conditions (Mumbai and Kolkata), whereas T. rubrum was prevalent in noncoastal areas (Delhi, Lucknow and Hyderabad). Tinea corporis (71.4%) and tinea cruris (62.0%) were the common clinical types observed. antifungal drug susceptibility testing data indicated that minimum inhibitory concentration required to inhibit the growth of 90% of organisms (MIC-90) was lowest for griseofulvin (0.25-3.0 μg/mL). Among oral antifungals, the mean MIC of itraconazole was within the range (0.84 [0.252] μg/ mL), whereas high mean MIC values were reported for terbinafine (0.05 [0.043] μg/mL). Among topical agents, lowest mean MIC values were reported for luliconazole (0.29 [0.286] μg/mL), eberconazole (0.32 [0.251]) μg/mL and amorolfine (0.60 [0.306]) μg/mL.

LIMITATIONS

Lack of correlation between in vitro antifungal susceptibility and clinical outcome and absence of defined MIC breakpoints.

CONCLUSION

T. rubrum was the most common, followed by T. mentagrophytes as an emerging/codominant fungal isolate in India. Tinea corporis was the most common clinical type of dermatophytosis. Mean MIC of terbinafine was above the reference range, while it was within the range for itraconazole; griseofulvin had the lowest mean MIC. Luliconazole presented the lowest mean MIC values across cities.

The Emerging Terbinafine-Resistant Trichophyton Epidemic: What Is the Role of Antifungal Susceptibility Testing?

BACKGROUND

Dermatophytosis is commonly encountered in the dermatological clinics. The main aetiological agents in dermatophytosis of skin and nails in humans are Trichophyton (T.) rubrum, T. mentagrophytes and T. interdigitale (former T. mentagrophytes-complex). Terbinafine therapy is usually effective in eradicating infections due to these species by inhibiting their squalene epoxidase (SQLE) enzyme, but increasing numbers of clinically resistant cases and mutations in the SQLE gene have been documented recently. Resistance to antimycotics is phenotypically determined by antifungal susceptibility testing (AFST). However, AFST is not routinely performed for dermatophytes and no breakpoints classifying isolates as susceptible or resistant are available, making it difficult to interpret the clinical impact of a minimal inhibitory concentration (MIC).

SUMMARY

PubMed was systematically searched for terbinafine susceptibility testing of dermatophytes on October 20, 2020, by two individual researchers. The inclusion criteria were in vitro terbinafine susceptibility testing of Trichophyton (T.) rubrum, T. mentagrophytes and T. interdigitale with the broth microdilution technique. The exclusion criteria were non-English written papers. Outcomes were reported as MIC range, geometric mean, modal MIC and MIC50 and MIC90 in which 50 or 90% of isolates were inhibited, respectively. The reported MICs ranged from <0.001 to >64 mg/L. The huge variation in MIC is partly explained by the heterogeneity of the Trichophyton isolates, where some originated from routine specimens (wild types) whereas others came from non-responding patients with a known SQLE gene mutation. Another reason for the great variation in MIC is the use of different AFST methods where MIC values are not directly comparable. High MICs were reported particularly in isolates with SQLE gene mutation. The following SQLE alterations were reported: F397L, L393F, L393S, H440Y, F393I, F393V, F415I, F415S, F415V, S443P, A448T, L335F/A448T, S395P/A448T, L393S/A448T, Q408L/A448T, F397L/A448T, I121M/V237I and H440Y/F484Y in terbinafine-resistant isolates.

Molecular Epidemiology and Antifungal Susceptibility of Trichophyton Isolates in Greece: Emergence of Terbinafine-Resistant Trichophytonmentagrophytes Type VIII Locally and Globally

Trichophyton isolates with reduced susceptibility to antifungals are now increasingly reported worldwide. We therefore studied the molecular epidemiology and the in vitro antifungal susceptibility patterns of Greek Trichophyton isolates over the last 10 years with the newly released EUCAST reference method for dermatophytes. Literature was reviewed to assess the global burden of antifungal resistance in Trichophyton spp. The in vitro susceptibility of 112 Trichophyton spp. molecularly identified clinical isolates (70 T. rubrum, 24 T. mentagrophytes, 12 T. interdigitale and 6 T. tonsurans) was tested against terbinafine, itraconazole, voriconazole and amorolfine (EUCAST E.DEF 11.0). Isolates were genotyped based on the internal transcribed spacer (ITS) sequences and the target gene squalene epoxidase (SQLE) was sequenced for isolates with reduced susceptibility to terbinafine. All T. rubrum, T. interdigitale and T. tonsurans isolates were classified as wild-type (WT) to all antifungals, whereas 9/24 (37.5%) T. mentagrophytes strains displayed elevated terbinafine MICs (0.25–8 mg/L) but not to azoles and amorolfine. All T. interdigitale isolates belonged to ITS Type II, while T. mentagrophytes isolates belonged to ITS Type III* (n = 11), VIII (n = 9) and VII (n = 4). All non-WT T. mentagrophytes isolates belonged to Indian Genotype VIII and harbored Leu393Ser (n = 5) and Phe397Leu (n = 4) SQLE mutations. Terbinafine resistance rates ranged globally from 0–44% for T. rubrum and 0–76% for T. interdigitale/T. mentagrophytes with strong endemicity. High incidence (37.5%) of terbinafine non-WT T. mentagrophytes isolates (all belonging to ITS Type VIII) without cross-resistance to other antifungals was found for the first time in Greece. This finding must alarm for susceptibility testing of dermatophytes at a local scale particularly in non-responding dermatophytoses.

Immunological response and clinical profile in patients with recurrent dermatophytosis

BACKGROUND

An alarming increase in the number of patients with chronic and recurrent dermatophytosis has invoked the need to study the immunological parameters of the host.

OBJECTIVES

To evaluate delayed type of hypersensitivity (DTH) response and immediate hypersensitivity (IH) response by flow cytometry evaluation of immune cells from peripheral blood and intradermal trichophyton skin test in patients with recurrent dermatophytosis.

METHODS

A hundred patients with recurrent dermatophytosis and 50 controls (healthy controls and acute dermatophytosis controls) were included. Relevant risk factors for recurrence were analysed, and serum IgE levels were estimated. Flow cytometry evaluation of immune cells in peripheral blood and intradermal trichophyton skin test was done. Dermatophyte pathogens were isolated, and antifungal susceptibility was performed.

RESULTS

Trichophyton mentagrophytes complex (95.84%) and T. rubrum (4.16%) were isolated in culture. Serum IgE was elevated in 83.15% cases (p = .01). IFN-γ⁺ cells (p = .0501, p = .0001, p = .0014), Th1 cells (p = .1197, p = .0024, p = .0169), IL-17⁺ cells (p = .0127, p = .0006, p = .0007) and Th17 cells (p = .0634, p = .0001, p = .0054) were reduced, and IL-4⁺ cells (p = .0108, p = .0175, p = .0018) were increased in cases. Intradermal test demonstrated negative DTH response in all cases (p < .001, p < .001, p < .001), strongly positive IH response in 6%, and borderline positive IH response in 85% cases (p = .018, p < .001, p < .001). Topical corticosteroids application, undergarment types (tight fit), poor frequency of washing clothes, family history of tinea, sharing of towels were significant risk factors for recurrent dermatophytosis.

CONCLUSIONS

Reduced IFN-γ⁺ , Th1, IL-17⁺ and Th17 cells population along with impaired DTH response by the intradermal test was observed in patients with recurrent dermatophytosis.

Immunopathogenesis of Dermatophytoses and Factors Leading to Recalcitrant Infections

The pathogenesis of dermatophytic infections involves the interplay of three major factors: the dermatophyte, the inherent host defense, and the adaptive host immune response. The fungal virulence factors determine the adhesion and invasion of the skin while the immune response depends on an interaction of the pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMP) with pattern recognition receptors (PRRs) of the host, which lead to a differential Th (T helper) 1, Th2, Th17, and Treg response. While anthropophilic dermatophytes Trichophyton rubrum and now increasingly by T. interdigitale subvert the immune response via mannans, zoophilic species are eliminated due to a brisk immune response. Notably, delayed-type hypersensitivity (Th1) response of T lymphocytes causes the elimination of fungal infection, while chronic disease caused by anthropophilic species corresponds to toll-like receptor 2 mediated IL (interleukin)-10 release and generation of T-regulatory cells with immunosuppressive potential. Major steps that determine the ultimate clinical course and chronicity include genetic susceptibility factors, impaired epidermal and immunological barriers, variations in the composition of sebum and sweat, carbon dioxide tension, skin pH, and topical steroid abuse. It is important to understand these multifarious aspects to surmount the problem of recalcitrant dermatophytosis when the disorder fails conventional therapeutic agents.

Complementary effect of mechanism of multidrug resistance in Trichophyton mentagrophytes isolated from human dermatophytoses of animal origin

BACKGROUND

Dermatophytoses have gained interest worldwide due to the increased resistance to terbinafine and azoles and difficulty in management of these refractory diseases.

OBJECTIVES

In this study, we identified and analysed Trichophyton mentagrophytes clinical isolates obtained from humans with infections of animal origin.

METHODS

We used quantitative real-time PCR (qRT-PCR) to examine the transcriptional modulation of three MDR genes (PDR1, MDR2 and MDR4) and analysed squalene epoxidase (SQLE) gene sequences from multidrug-resistant Trichophyton mentagrophytes isolates.

RESULTS

The expression profile revealed a 2- to 12-fold increase in mRNA accumulation in the presence of any of the antifungals, compared to cells incubated without drugs. A statistically significant relationship between the isolates exposed to itraconazole and increased expression of the tested genes was revealed. Substantially lower transcription levels were noted for cells exposed to luliconazole, that is, a third-generation azole. Additionally, in the case of 50% of terbinafine-resistant strains, Leu397Phe substitution in the SQLE gene was detected. Furthermore, the reduced susceptibility to itraconazole and voriconazole was overcome by milbemycin oxime.

CONCLUSIONS

In conclusion, our study shed more light on the role of the ABC transporter family in T. mentagrophytes, which, if overexpressed, can confer resistance to single azole drugs and even cross-resistance. Finally, milbemycin oxime could be an interesting compound supporting treatment with azole drugs in the case of refractory dermatomycoses.

Autoimplantation Therapy in Extensive and Recalcitrant Dermatophytosis: A Case Series

Dermatophytosis is one of the most common diseases worldwide and is difficult to treat due to its recalcitrant nature. Conventional treatment modalities are associated with frequent relapses due to the absence of a host immune interaction. Here, we present a case series of three patients with difficult-to-treat and recalcitrant dermatophytosis who were treated with homologous autoimplantation. Complete clearance of dermatophytosis was observed after three months in two of the patients and after two and a half months in one patient without the use of any antifungals. No relapses were observed within six months of follow-up. The outcomes of the three patients presented in this case series support homologous autoimplantation as a safe and effective procedure for the treatment of recalcitrant dermatophytosis. The procedure requires only a single visit that can be performed either alone or in combination with other modalities.

Topical clotrimazole cream for the treatment of tinea cruris: A retrospective study

This retrospective study assessed the efficacy and safety of 1% topical clotrimazole cream for the treatment of patients with tinea cruris (TC).We included 86 patients with confirmed TC for the presence of fungal hyphae. Of those, 43 patients received 1% topical clotrimazole cream for a total of 4 consecutive weeks, and were assigned to an experimental group. The other 43 patients underwent 1% topical butenafine cream for a total of 2 consecutive weeks, and were allocated to a control group. The efficacy and safety were measured and analyzed after 4 weeks treatment.After treatment, patients in both groups achieved better improvements in erythema (P < .01), scaling (P < .01), itching (P < .01), and KOH-negative results (P < .01), compared with those in patients before the treatment. However, there were not significant differences in erythema (P = .61), scaling (P = .57), itching (P = .47), and KOH-negative results (P = .67) between 2 groups. In addition, no treatment-related adverse events were recorded in both groups.Both 1% topical clotrimazole and butenafine cream are found to be effective and safe for patients with TC. However, there is not significant difference in efficacy and safety between two groups.

Indian Association of Dermatologists, Venereologists and Leprologists (IADVL) Task Force against Recalcitrant Tinea (ITART) Consensus on the Management of Glabrous Tinea (INTACT)

Background and Aims:

Dermatophytosis has always been a common superficial mycosis in India. However, the past 6-7 years have seen an unprecedented increase in the number of patients affected by recurrent, chronic, recalcitrant and steroid modified dermatophytosis involving the glabrous skin (tinea corporis, tinea cruris and tinea faciei). Importantly, there has been a notable decrease in clinical responsiveness to commonly used antifungals given in conventional doses and durations resulting in difficult-to-treat infections. Considering that scientific data on the management of the current epidemic of dermatophytosis in India are inadequate, the Indian Association of Dermatologists, Venereologists and Leprologists (IADVL) Task force Against Recalcitrant Tinea (ITART) has formulated a consensus statement on the management of dermatophytosis in India.

Methods:

Seventeen dermatologists with a focussed interest in dermatophytosis participated in a Delphi consensus method, conducted in three rounds. They responded as either “agree” or “disagree” to 132 statements prepared by the lead experts and gave their comments. Consensus was defined as an agreement of 80% or higher concurrence. Statements on which there was no consensus were modified based on the comments and were then recirculated. The results were finally analysed in a face-to-face meeting and the responses were further evaluated. A draft of the consensus was circulated among the participants and modified based on their inputs.

Results:

Consensus was achieved on 90 of the 132 statements. Direct microscopy using potassium hydroxide mount was recommended in case of diagnostic difficulty on clinical examination. Counselling of patients about strict adherence to general measures and compliance to treatment was strongly recommended as the key to successful management of dermatophytosis. A combination of systemic and topical antifungal drugs was recommended for the treatment of glabrous tinea in the current scenario. Topical corticosteroid use, whether used alone or in combination with other components, was strongly discouraged by all the experts. It was suggested that topical antifungals may be continued for 2 weeks beyond clinical resolution. Itraconazole and terbinafine were recommended to be used as the first line options in systemic therapy, whereas griseofulvin and fluconazole are alternatives. Terbinafine was agreed to be used as a first line systemic agent in treatment naïve and terbinafine naïve patients with glabrous tinea. Regular follow-up of patients to ensure compliance and monitoring of clinical response was recommended by the experts, both during treatment and for at least 4 weeks after apparent clinical cure. Longer duration of treatment was recommended for patients with chronic, recurrent and steroid modified dermatophytosis.

Conclusion:

Consensus in the management of dermatophytosis is necessary in the face of conventional regimens proving ineffective and dearth of clinical trials re-evaluating the role of available antifungals in the wake of evolving epidemiology of the infection in the country. It needs to be backed by more research to provide the required level of evidence. It is hoped that this consensus statement improves the quality of care for patients with dermatophytosis, which has emerged as a huge public health problem, imposing considerable financial burden on the country.

Skin Barrier Function Defect - A Marker of Recalcitrant Tinea Infections

Context:

Recently, there has been an increase in the number of chronic, recurrent, and recalcitrant dermatophytosis. Many factors implicated are barrier defects, aberrant host immune response, application of steroids or other irrational combination creams, transmission within family, occlusive clothing, poor hygienic conditions, poor compliance, drug resistance and virulence of the infecting strain. Transepidermal water loss (TEWL) is an important index in accessing the barrier function of skin.

Aim:

To ascertain the role of TEWL from the lesional skin and its effect on the cure rate and relapse in patients of tinea cruris.

Materials and Method:

A hospital based prospective comparative study was conducted for 1 year. A total of 200 patients of tinea cruris diagnosed clinically and by KOH examination, were included in the study. TEWL was calculated using Tewameter TM300 open chamber probe of Courage and Khazaka, Cologne, Germany. Patients were classified according to the TEWL values into Group A (patients with abnormal TEWL) and Group B (normal TEWL). Both groups were given oral itraconazole and antihistamines for 4 weeks. The cure rates and recurrence rates of both the groups were analyzed and compared.

Results:

In the Group A, i.e., patients of tinea cruris with abnormal TEWL, only 28% of the patients showed clinical improvement at the end of 1 month. Out of those cured, 78.57% of the cases showed recurrence after 2 months of completion of therapy. In Group B, i.e., patients of tinea cruris with normal TEWL, 69% (n = 69) of the patients showed clinical improvement at the end of 1 month. Out of those cured, only 21.74% of the cases (n = 15) showed recurrence.

Conclusion:

The cases of tinea cruris with abnormal TEWL show significant decrease in cure rates and significant relapse rates among those initially cured.

Alarming India-wide phenomenon of antifungal resistance in dermatophytes: A multicentre study

BACKGROUND

An alarming increase in recalcitrant dermatophytosis has been witnessed in India over the past decade. Drug resistance may play a major role in this scenario.

OBJECTIVES

The aim of the present study was to determine the prevalence of in vitro resistance to terbinafine, itraconazole and voriconazole in dermatophytes, and to identify underlying mutations in the fungal squalene epoxidase (SQLE) gene.

PATIENTS/METHODS

We analysed skin samples from 402 patients originating from eight locations in India. Fungi were identified by microbiological and molecular methods, tested for antifungal susceptibility (terbinafine, itraconazole, voriconazole), and investigated for missense mutations in SQLE.

RESULTS

Trichophyton (T.) mentagrophytes internal transcribed spacer (ITS) Type VIII was found in 314 (78%) samples. Eighteen (5%) samples harboured species identified up to the T interdigitale/mentagrophytes complex, and T rubrum was detected in 19 (5%) samples. 71% of isolates were resistant to terbinafine. The amino acid substitution Phe397Leu in the squalene epoxidase of resistant T mentagrophytes was highly prevalent (91%). Two novel substitutions in resistant Trichophyton strains, Ser395Pro and Ser443Pro, were discovered. The substitution Ala448Thr was found in terbinafine-sensitive and terbinafine-resistant isolates but was associated with increased MICs of itraconazole and voriconazole.

CONCLUSIONS

The high frequencies of terbinafine resistance in dermatophytes are worrisome and demand monitoring and further research. Squalene epoxidase substitutions between Leu393 and Ser443 could serve as markers of resistance in the future.

An exploratory pilot analysis of the optimal pellet number in 100 mg of itraconazole capsule to maximize the surface area to satisfy the Noyes-Whitney equation

INTRODUCTION

Recalcitrant dermatophytoses is on the rise. With increasing microbiological resistance and clinical failures reported to terbinafine, itraconazole (ITR) is being increasingly used for the condition. ITR has an unpredictable bioavailability and quality variation among brands is known to affect clinical outcome. Bioequivalence to innovator brand is often not established and many spurious brands have flooded the market. Morphometric characteristics of the pellets, especially their count, size, and surface area impact dissolution of drug in the gastrointestinal tract, as per the Noyes-Whitney equation. It would be of value to clinicians to be able to differentiate good quality from poorly manufactured brands to achieve optimum clinical results, especially when rigorously done bioequivalence studies are not available.

AIMS

We aimed to study the morphometric characteristics of various ITR brands and arrive at a pellet count which would present a surface area for absorption comparable to that of the innovator brand.

METHODOLOGY

Pellet count was done manually and size was estimated using a dermoscope. Surface area of each brand was calculated and comparisons done between different sub groups formed on the basis of pellet count.

RESULTS

There is significant variation in the morphometric characteristics of pellets among different brands. A pellet count of ≥560 provides a surface area comparable to the innovator brand.

CONCLUSION

Pellet count of 560 or above provides an optimal surface area for absorption of ITR from GI tract. In the absence of bioequivalence studies with the innovator brand, this may be taken as a cut off for distinguishing poor quality ITR brands.

Clinicomycological Study of Dermatophytosis in a Tertiary Care Hospital in Eastern India: A Cross-sectional Study

Introduction:

Dermatophytosis is a fungal infection of the skin, hair, and nails. In the past several years, it has emerged as a general public health problem in our country. Studies from different regions reveal varying patterns of etiological distribution of the disease.

Aims and Objectives:

To estimate the prevalence of different fungal species associated with dermatophytosis and to find out any possible association of the type of fungus with different clinical parameters of the disease.

Materials and Methods:

This was a cross-sectional study among 311 clinically diagnosed dermatophytosis cases from a tertiary care center in eastern India. Potassium hydroxide (KOH) mount and fungal culture were done from samples of skin, hair, and nails, and various clinical parameters were analyzed.

Results:

There was a male preponderance among cases and maximum patients belonged to third decade of life. Most common presentation was tinea corporis et cruris (39.5%). Family history was positive in 48.8% of cases. Trichophyton mentagrophytes was the most common fungal species (79.91%) grown in culture followed by Trichophyton rubrum (13.53%). Majority of patients had a mild body surface area involvement. We did not find statistically significant association of any clinical parameters with type of organism isolated.

Conclusion:

Trichophyton mentagrophytes was the most common isolated fungal species. This is in contrast to several studies where T.rubrum was the frequently found organism. There was no significant association of any clinical parameters like body surface area, number of sites, or duration of diseasewith fungal species isolated in culture.

The effect of isoflavaspidic acid PB extracted from Dryopteris fragrans (L.) Schott on planktonic and biofilm growth of dermatophytes and the possible mechanism of antibiofilm

ETHNOPHARMACOLOGICAL RELEVANCE

Dryopteris fragrans (L.) Schott (D. fragrans), a deciduous perennial herb, has been traditionally used for treatment of various skin diseases in Heilongjiang province of China for many years. Phloroglucinol derivatives extracted from D. fragrans were the most effective fraction against dermatophytes. Isoflavaspidic acid PB is a typically phloroglucinol derivative which extracted from D. fragrans and has been reported to exert anti-fungal activities against several dermatophytes.

AIM OF THE STUDY

This study aimed to evaluate anti-fungal and anti-biofilm activity of isoflavaspidic acid PB on planktonic and biofilm growth of dermatophytes and explore possible mechanisms of anti-biofilm.

MATERIALS AND METHODS

Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) of isoflavaspidic acid PB against 25 isolates of dermatophytes were determined by the Clinical and Laboratory Standards Institute (CLSI) M38-A2 method. The effects of isoflavaspidic acid PB on dermatophytes biofilm formation and pre-formed biofilm were assessed by 2.3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[carbonyl (phenylamino)]-2H-tetrazolium hydroxide (XTT) assay. Morphology of mature biofilm were observed by Scanning Electron Microscope (SEM). Biomass, exopolysaccharide and ergosterol content of mature biofilm were analyzed by gravimetric analysis, anthranone sulfuric acid method and Ultra Performance Liquid Chromatography (UPLC) assay respectively.

RESULT

The MIC and MFC ranges of isoflavaspidic acid PB against 25 isolates of dermatophytes were 20-80 μg/mL and 40-80 μg/mL respectively. Isoflavaspidic acid PB (2 MIC) inhibited not only Trichophyton biofilm formation (54.8% ∼ 81.2%) but also the metabolic activity of mature biofilm (20.7% ∼ 44.2%). The result of SEM showed that isoflavaspidic acid PB (8 MIC) could destroy the morphology of hyphae seriously. Comparing with control group, biomass, exopolysaccharide and ergosterol content of the mature biofilm under isoflavaspidic acid PB (8 MIC) were significantly decreased (P < 0.01).

CONCLUSION

Isoflavaspidic acid PB had anti-fungal and fungicidal activities against dermatophytes. Isoflavaspidic acid PB could inhibit the biofilm of Trichophyton. The mechanism might be related to the decline of the biofilm biomass, exopolysaccharide and ergosterol content. These results showed that isoflavaspidic acid PB could be explored for promising anti-biofilm drugs.

Determination of antifungal minimum inhibitory concentration and its clinical correlation among treatment failure cases of dermatophytosis

Introduction:

Dermatophytes are most common infectious agents causing superficial mycosis worldwide. A number of topical as well as systemic antifungal drugs are available for treatment of dermatophytosis. Superficial mycosis caused by dermatophytes can be easily treated by topical or oral antifungal drugs, but in the course of time, an increased number of treatment failure cases are appearing. Possible cause for treatment failure could be poor patient compliance, poor drug penetration into affected lesion, and also drug resistance in dermatophytes. The aim of this study is to investigate minimum inhibitory concentration and clinical correlation in treatment failure cases of dermatophytosis.

Methods:

Skin, hair and nail samples were collected from treatment failure cases of dermatophytosis. A total 75 isolates were tested for MIC against four antifungal drugs in the study. Fluconazole, itraconazole, ketoconazole and terbinafine were the antifungal drugs tested using broth microdilution method. MIC₅₀ and MIC₉₀ values were recorded.

Results:

A total of 75 dermatophytic isolates were tested. Dermatophytic isolates in this study were Trichophyton mentagrophytes (n = 31), T. rubrum (n = 13), T. tonsurans (n = 12), T. verrucosum (n = 9), M. gypseum (n = 5), E. floccosum (n = 4) and T. violaceum (n = 1). MIC₉₀ value for fluconazole and terbinafine was significantly higher.

Conclusion:

MIC of 17.33% isolates for fluconazole and 33.33% isolates for terbinafine were lower than cut-off value, which indicates that not all treatment failure cases are due to drug resistance.

Antifungal resistance in dermatophytes: Recent trends and therapeutic implications

Dermatophytoses or tinea refers to superficial fungal infection of keratinized tissues. Although generally considered easy to treat, recalcitrant infections, presenting as extensive and difficult to treat tinea corporis and cruris, are on the rise in some parts of the world. The situation demands an understanding of the pharmacokinetic and pharmacodynamic properties of the available antifungals against dermatophytes and the possible contribution of drug resistance and other factors to the present scenario. In this review, we provide the readers a comprehensive account of the available literature on in-vitro and in-vivo resistance to clinically used antifungals among dermatophytes. We have also added, in brief, the relevant skin pharmacokinetics of important systemic drugs. The established and postulated mechanisms of drug resistance are discussed and aspects on lack of in vivo correlation of in vitro resistance are presented. Finally, the lacunae in our existing knowledge on the topic and the arenas for future research are highlighted.

Parameters that determine dissolution and efficacy of itraconazole and its relevance to recalcitrant dermatophytoses

INTRODUCTION

Recalcitrant dermatophytoses is on the rise. Though myriad factors contribute to recalcitrance including terbinafine resistance, itraconazole largely remains sensitive. However, there are increasing instances of patients not responding adequately to itraconazole despite low MICs, probably due to issues plaguing the pelletization process, resulting in suboptimal quality. Data on this topic was searched on pubmed using the search items: itraconazole, MIC, MFC, quality, assay, pharmacokinetics, pharmacodynamics, dermatophytoses, and recalcitrance. Areas covered: A detailed analysis of the manufacturing process of itraconazole with emphasis on pelletization and parameters affecting the dissolution and bioavailability is presented. Important formulation factors including drug-polymer ratio, polymer type, coating thickness, bead size, and number are discussed. Also covered is the rationale of dosimetry of itraconazole in dermatophytoses based on the skin pharmacokinetics and MIC of the organism. Expert opinion: The process of pelletization has multiple components aiming to achieve maximum dissolution of the drug. Variations in the process, pellet quality, number, and polymer determine absorption. Morphometric analysis of pellets is a simple method to quantify quality of the drug. Once the process has been standardized, dosimetry depends on the route of secretion and site of infection, accounting for the variation of doses from 100 mg to 400 mg/day.