Evaluation of efficacy and safety of oral terbinafine and itraconazole combination therapy in the management of dermatophytosis

Trichophyton indotineae, an Emerging Drug-Resistant Dermatophyte: A Review of the Treatment Options

Background: Dermatophytosis is a prevalent superficial infection caused by filamentous fungi, primarily affecting the skin and/or its appendages. In recent years, there has been a notable increase in mycotic strains resistant to standard antifungal therapies, including Trichophyton indotineae, a dermatophyte of the Trichophyton mentagrophytes complex. This review aims to provide a comprehensive overview of the treatment options for T. indotineae, elucidating their effectiveness in managing this challenging mycotic infection. Methods: For this review, a search was conducted in the PubMed, Scopus, Web of Science, Embase, and Google Scholar databases, encompassing all published data until March 2024. English-language articles detailing therapy outcomes for patients confirmed to be affected by T. indotineae, identified through molecular analysis, were included. Results: Itraconazole was shown to be a good therapeutic choice, particularly when administered at a dosage of 200 mg/day for 1-12 weeks. Voriconazole was also demonstrated to be effective, while terbinafine exhibited a reduced response rate. Griseofulvin and fluconazole, on the other hand, were found to be ineffective. Although topical treatments were mostly ineffective when used alone, they showed promising results when used in combination with systemic therapy. Mutational status was associated with different profiles of treatment response, suggesting the need for a more tailored approach. Conclusions: When managing T. indotineae infections, it is necessary to optimize therapy to mitigate resistances and relapse. Combining in vitro antifungal susceptibility testing with mutational analysis could be a promising strategy in refining treatment selection.

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.

Combination oral antifungal therapy for paediatric fungal infection: An option to improve efficacy and overcome clinical resistance

There is increasing evidence of clinically resistant cutaneous fungal infections. The use of combination oral antifungals is described in adults but not in paediatric patients. We present seven paediatric cases of clinically resistant fungal infections treated successfully with combination oral antifungal therapy after inadequate response to a single agent.

Diagnosis of a recurred lesion in dermatophytosis patients after 2 weeks of antifungal therapy: A prospective observational study

Few researchers believe that various risk factors may complicate the course of dermatophytosis and/or develop various dermatoses unrelated to fungal infection at the previous lesion site. However, there is a paucity of studies that analyzed the diagnosis of lesions that recurred at the treated site of dermatophytosis.

Materials and Methods

A prospective observational study was conducted on 157 cases of dermatophytosis with positive fungal test results. A fixed dose of 100 mg of oral itraconazole once daily was administered to all patients for 2 weeks. At the end of 2 weeks, patients were assessed for clinical cure and recurrence. Recurred cases were assessed for mycological profile using a fungal test (potassium hydroxide mount and/or fungal culture) for identifying fungal infection.

Results

Only eight (5.36%) patients showed clinical cure, and 141 (94.63%) patients developed recurrence after therapy. Of the 141 cases with recurrence, only 47 (33.33%) patients were positive for fungus. Eight (5.09%) patients were lost to follow-up. Frequently encountered risk factors in the study were topical steroid use, disease in family, associated atopic dermatitis and contact with pets.

Conclusion

This is the first study that described the clinical diagnosis and mycological profile of the various lesions recurring at the previous tinea infection site in patients with dermatophytosis. Such patients presented not only with recurrent lesions of fungal infection but also developed various dermatoses unrelated to fungal infection at the sites of previous tinea infection. Various factors, which could have resulted in the observed changes, are reinfection by dermatophytes at the sites of previous tinea infection, inadequate antifungal therapy or antifungal resistance; or due to the effects of various topical steroid formulations used by the patients, such as anti-inflammatory or immunosuppressive effects or shift in immunity. Hence, diagnosis of the recurrent lesion at the site of previous dermatophytosis must be individualized and should be based on 1) duration of antifungal therapy received, 2) associated risk factors, 3) response to antifungal therapy, 4) evolution of the recurrent lesion, and/or 5) fungal tests.

Comparison between the efficacy of terbinafine and itraconazole orally vs. the combination of the two drugs in treating recalcitrant dermatophytosis

Fungal infections are a challenging to treat cutaneous condition. Approximately 20-25% of humans are affected by superficial fungal infections that invade and multiply within keratinized tissues. To compare the efficacy of either terbinafine or itraconazole orally versus the combination of the two drugs in the treatment of recalcitrant dermatophytosis. The current study included 45 patients with recalcitrant dermatophytosis who were distributed into 3 groups (each of 15 patients); Group A received terbinafine 250 mg twice a day for 4 weeks. Group B received itraconazole 200 mg twice a day for 4 weeks. Group C received terbinafine 250 mg once daily and itraconazole 200 mg once daily for 4 weeks. The patients were followed up for 12 weeks after initiation of treatment by clinical and microbiological assessment to determine the cure rate. At the end of twelve weeks, 12 (80%) patients in group A; 13 (86.7%) patients in group B and 15 (100%) patients in group C were completely cured. Despite of cure rates being higher in the combined group C; yet results were not statistically significant (p = 0.207). Clinical cure rates were non significantly higher in itraconazole + terbinafine combined group (p = 0.207). Combination of terbinafine and itraconazole had a higher clinical and mycological cure rate when compared to the use of either drug alone as monotherapy. Further randomized, multicenter, large cohort studies are warranted to validate the use of combination antifungal treatments.

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.

Superficial Dermatophytosis across the World's Populations: Potential Benefits from Nanocarrier-Based Therapies and Rising Challenges

The most prevalent infection in the world is dermatophytosis, which is a major issue with high recurrence and can affect the entire body including the skin, hair, and nails. The major goal of this Review is to acquire knowledge about cutting-edge approaches for treating dermatophytosis efficiently by adding antifungals to formulations based on nanocarriers in order to overcome the shortcomings of standard treatment methods. Updates on nanosystems and research developments on animal and clinical investigations are also presented. Along with the currently licensed formulations, the investigation also emphasizes novel therapies and existing therapeutic alternatives that can be used to control dermatophytosis. The Review also summarizes recent developments on the prevalence, management approaches, and disadvantages of standard dosage types. There are a number of therapeutic strategies for the treatment of dermatophytosis that have good clinical cure rates but also drawbacks such as antifungal drug resistance and unfavorable side effects. To improve therapeutic activity and get around the drawbacks of the traditional therapy approaches for dermatophytosis, efforts have been described in recent years to combine several antifungal drugs into new carriers. These formulations have been successful in providing improved antifungal activity, longer drug retention, improved effectiveness, higher skin penetration, and sustained drug release.

Efficacy and safety of Majoon Ushba oral and Marham Raal topical in tinea corporis - A randomized open-labeled active-controlled clinical trial

OBJECTIVE

Tinea Corporis is the most frequent form of dermatophytosis reported as the commonest presentation. Majoon Ushba (MU) a polyherbal preparation in a semisolid oral dosage form and Marham Raal (MR) an ointment made up of herbal and animal drugs are used for skin disorders in Unai medicine. Considering the biologically active substances with antioxidant, antimicrobial, antifungal, anti-inflammatory, and wound-healing properties of their ingredients, this study aimed to evaluate the clinical and mycological efficacy and safety of MU and MR in tinea corporis.

METHODS

This randomized open-labeled active-controlled clinical trial was conducted on 42 patients of tinea corporis. Patients were randomly assigned via a computer-generated list to the test group (n=21) receiving oral MU (6 gm) with topical MR and the control group (n=21) topical terbinafine hydrochloride (1%) for 40 days. The severity scores of clinical symptoms; erythema, scaling, itching, margins, and size were the primary outcome and the mycological cure (negative KOH microscopy), total score, and dermatology life quality index (DLQI) were the secondary outcomes were analyzed at baseline and at 40 days.

RESULTS

A significant reduction was observed in clinical severity scores of erythema, scaling, and itching (P ≤ 0.05) in both groups except for margins, and size of the lesion (P ≥ 0.05). The mycological cure (P = .001) and the total score (P = 0.0002) and DLQI (P = 0.002) were statistically significant in both groups when analyzed from baseline to the end of the treatment within groups, however, the differences in these outcomes were statistically insignificant (P ≥ 0.05) on the inter-group comparison. All the safety parameters (clinical and laboratory) were in the normal range in both groups.

CONCLUSION

The results demonstrated that traditional and conventional treatments were equally effective and MU and MR can be prescribed as alternative or complementary treatments for tinea corporis.

Assessing the efficacy and safety of Unani pharmacopoeial formulations in dermatophytosis (quba) - a randomized controlled trial

OBJECTIVES

The recent trends of rising unresponsive cases of dermatophytosis to conventional therapies pose a challenge in clinical practice. Unani medicine offers effective treatment for dermatophytosis. This study aimed to evaluate the efficacy and safety of the Unani herbo-mineral preparations Qurs-e-Asfar (QA) and Rogan-e-Narjeel (RN) in dermatophytosis.

METHODS

This was a randomized, active-controlled and open-label clinical study. The participants diagnosed with dermatophytosis (n=78) randomized into treatment group (n=40) receiving oral QA (778 mg twice a day) and topical RN and control group (n=38) receiving oral Itraconazole (100 mg/day) and topical Terbinafine hydrochloride (1%) for 6 weeks.

RESULTS

We found post-treatment improvement in itching by 86.3% vs. 78% (treatment vs. control group), erythema by 96.4% vs. 94.3%, scaling by 93% vs. 92.2% and peripheral raised margins by 82.3% vs. 81%. Furthermore, this study showed that the differences in the mean Total Signs and Symptoms Score (TSSS) and positive KOH mount were clinically and statistically significant (p<0.05) in both the groups. On comparing inter group, the differences in mean TSSS (p=0.07) and positive KOH mount (p=0.717) were found statistically insignificant.

CONCLUSIONS

This study concludes that the formulations QA and RN were effective and safe in the treatment of dermatophytosis.

Management of Dermatophytosis: Real-World Indian Perspective

Background

In spite of the availability of multiple consensus statements on dermatophytosis management, different treatment approaches have been experienced in India and require more scrutiny to further update guidelines and improve patient care.

Aim

To determine the different approaches in dermatophytosis diagnosis and management among dermatologists in India.

Materials and Methods

A web-based questionnaire was created and validated by five panelists with experience of >15 years in dermatophytosis and then circulated to about 2,000 dermatologists in India in September 2021 for a real-world management scenario.

Results

Out of 2,000 dermatologists, 459 responded. About half of the dermatologists (51%) routinely conduct potassium hydroxide mount (KOH) at the initiation of therapy. Similarly, about 53% of dermatologists initiate the management of dermatophytosis with combination therapy in all types of dermatophytosis for 4-6 weeks depending upon severity. Different types of combinations are being practiced, such as either two systemic and one topical, two topicals and one systemic, but the combination of one systemic and one topical (69%) is the most commonly practiced. Itraconazole (100 mg twice a day) and luliconazole are the most commonly prescribed antifungal medications. In case of non-response to routine dose of systemic anti-fungals, about 72% of dermatologists up dose them. Most of them continue these drugs for additional 1-2 weeks after clearance of the disease. Additionally, keratolytics and moisturizers are commonly prescribed. Additionally, 62% advise liver function tests (LFTs) at the initiation of therapy, whereas 72% advise monitoring adverse effects due to systemic antifungal drugs during treatment.

Conclusion

Combination therapy stood out as the need of the hour in the current menace of dermatophytosis with timely monitoring of laboratory tests for adverse events due to the use of systemic antifungals for a longer duration.

Effect of Different Itraconazole Dosing Regimens on Cure Rates, Treatment Duration, Safety, and Relapse Rates in Adult Patients With Tinea Corporis/Cruris: A Randomized Clinical Trial

Importance

With worldwide emergence of recalcitrant and resistant dermatophytosis, itraconazole is increasingly being used as the first-line drug for treatment of tinea corporis/cruris (TCC). Apparent inadequacy with low doses has led to empirical use of higher doses and antifungal combinations.

Objective

To compare cure rates, treatment durations, safety profiles, and relapse rates of itraconazole 100, 200, and 400 mg/d for the treatment of TCC.

Design, Setting, and Participants

This double-blind randomized clinical trial included adult patients with treatment-naive TCC involving at least 5% body surface area. Patients were recruited from the dermatology outpatient department of a tertiary care hospital in New Delhi, India between March 1, 2020, and August 31, 2021.

Interventions

Patients were randomized to 1 of the 3 treatment groups. Biweekly blinded assessments were performed until cure or treatment failure. Posttreatment follow-up of at least 8 weeks was conducted to detect relapses.

Main Outcome and Measures

Cure rates, treatment durations, safety profiles, and relapse rates were assessed. Secondary outcomes included comparison of rapidity of clinical response and cost-effectiveness between groups.

Results

Of the 149 patients assessed, the mean (SD) age was 34.3 (12.2) years, 69 patients (46.4%) were women, and 80 patients (53.6%) were men. The difference in cure rate between the 100- and 200-mg groups was statistically nonsignificant (hazard ratio [HR], 1.44; 95% CI, 0.91-2.30; P = .12), while the difference between the 100- and 400-mg groups (HR, 2.87; 95% CI, 1.78-4.62; P < .001) and between the 200- and 400-mg groups (HR, 1.99; 95% CI, 1.28-3.09; P = .002) was statistically significant. Mean (SD) treatment durations were statistically significantly different between the 100- and 400-mg groups (7.7 [4.7] weeks vs 5.2 [2.6] weeks; P = .03) and between the 200- and 400-mg groups (7.2 [3.8] weeks vs 5.2 [2.6] weeks; P = .004), but the difference between the 100- and 200-mg groups was not statistically significant. A total of 55 patients (47.4%) relapsed after treatment. Relapse rates were comparable across groups. No patient discontinued treatment due to adverse effects. Treatment with the 200-mg dose incurred a 63% higher cost and 400 mg a 120% higher cost over 100 mg in achieving cure.

Conclusions and Relevance

In this randomized clinical trial, high overall efficacy was observed among the 3 itraconazole doses for treatment of TCC, but with prolonged treatment durations and considerable relapse rates. Treatment with the 200- and 100-mg doses did not differ significantly in efficacy or treatment durations, while 400 mg scored over the other 2 on these outcomes. Considerable additional cost is incurred in achieving cure with the 200- and 400-mg doses.

Trial Registration

Clinical Trials Registry of India Identifier: CTRI/2020/03/024326.

Voriconazole is superior to combined itraconazole/isotretinoin therapy and itraconazole monotherapy in recalcitrant dermatophytosis

BACKGROUND

There has been an emergence of recalcitrant, recurrent, and difficult-to-treat tinea. Monotherapy with oral antifungals leads to partial clearance or high recurrence of lesions. Isotretinoin is a good adjuvant to systemic antifungals in chronic dermatophytosis. Voriconazole could be a future alternative due to its efficacy against dermatophytes and little resistance.

OBJECTIVE

To evaluate the efficacy and safety of oral itraconazole, combined itraconazole/isotretinoin therapy, and voriconazole for recalcitrant tinea.

PATIENTS AND METHODS

This study included 90 patients with chronic, recurrent, and/or recalcitrant tinea. They were equally divided into 3 groups: itraconazole monotherapy, combined itraconazole/isotretinoin therapy, and voriconazole monotherapy. All patients received treatments for 6 weeks. The clinical response was classified as either a complete or incomplete clinical cure. Potassium hydroxide microscopy and culture were performed to identify mycological cure. Patients with complete cure were followed up for another 6 months to detect any recurrence.

RESULTS

Complete clinical cure was observed in 53.3% of the itraconazole group, 70% of the itraconazole/isotretinoin group, and 83.3% of the voriconazole group. Mycological cure was detected in 56.7% of the itraconazole group, 83.3% of the itraconazole/isotretinoin group, and 86.7% of the voriconazole group. There was a statistically significant difference between the three groups in favor of voriconazole, then the combined group. No significant adverse effects were observed. The recurrence rate was significantly lower in the voriconazole group compared to the other two groups.

CONCLUSIONS

Voriconazole could be a future alternative for the treatment of recalcitrant dermatophytosis.

Photodynamic therapy-mediated extirpation of cutaneous resistant dermatophytosis with Ag@ZnO nanoparticles: an efficient therapeutic approach for onychomycosis

Aim: The aim of this study was to determine whether photodynamic therapy of resistant onychomycosis with Ag@ZnO nanoparticles can promote the treatment procedure and extirpates the recurrence of fungal infection. Methods: Ag@ZnO nanoparticles (NPs) under UVB-radiation were applied to treat T. rubrum and T. mentagrophytes in vitro through photodynamic therapy. In vivo therapeutic efficacy, biocompatibility and biodistribution of Ag@ZnO NPs were studied. Results: 40 μg/ml of UVB-activated Ag@ZnO NPs showed 100% antifungal activity against dermatophytosis in vitro and in vivo followed by complete growth prevention by degeneration of spores and mycelium after 180 days, while posed biocompatibility. Conclusion: This study showed the superiority of photodynamic therapy with Ag@ZnO NPs followed by proper regeneration of the skin with Zinc ion of the shell.

Molecular identification and antifungal susceptibility of 75 clinical isolates of Trichophyton spp. from southern Brazil

BACKGROUND

Dermatophytoses affect more than 20% of the world's population and is caused by filamentous fungi, mainly of the genus Trichophyton. The species identification through microscopic direct examination and culture methods is challenging, with molecular presenting high sensitivity and specificity. Although there are several therapy options for dermatophyte infections, treatment failures and antifungal resistance are growing concerns.

OBJECTIVE

This study aimed to identify clinical isolates of Trichophyton spp. from southern Brazil using molecular methods and determine their in-vitro antifungal susceptibility.

MATERIAL AND METHODS

Seventy-five isolates were identified through sequencing of the ITS region. The exposure to seven antifungals drugs was performed according to protocol M28-A2 of the Clinical and Laboratory Standards Institute (CLSI).

RESULTS

Sixty-one isolates (81%) were identified as T. interdigitale, which differs from the epidemiological data present in the literature. Thirteen isolates were identified as T. rubrum and one as T. tonsurans. Terbinafine was the most effective antifungal, followed by itraconazole and voriconazole, which is in accordance with the results reported in previous studies.

CONCLUSIONS

The use of molecular methods to identify Trichophyton spp. clinical isolates and the performance of susceptibility tests are relevant to epidemiological data, identification of the emergence of antifungal resistance, and to help to translate the in-vitro antifungal susceptibility results into clinical practice.

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

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.

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.

Diagnosis, treatment, and outcome in a dog with systemic Mycoleptodiscus indicus infection

Objective

Describe the diagnosis, clinical course, and management of a dog with systemic Mycoleptodiscus indicus infection.

Case Summary

A 5‐year‐old male neutered Giant Schnauzer presented with left eye anterior uveitis, peripheral lymphadenopathy, hyperglobulinemia, anemia, and thrombocytopenia. A diagnosis of M. indicus infection was made based on histopathology and PCR. Treatment with itraconazole and terbinafine resulted in resolution of the hyperglobulinemia, anemia, thrombocytopenia, and peripheral lymphadenopathy. No evidence of fungal organisms was identified on lymph node, liver, or ocular histopathology after 7 months of treatment.

New or Unique Information Provided

This case is the first report of a systemic M. indicus infection in an apparently immunocompetent dog. Clinical resolution was achieved with systemic itraconazole and terbinafine.

The Growing Problem of Antifungal Resistance in Onychomycosis and Other Superficial Mycoses

Superficial mycoses are becoming increasingly resistant to current antifungal medications. As alternative therapeutic options are limited, the increasing frequency of reports of antifungal resistance is alarming. This epidemic parallels the rise of antibiotic resistance; however, the significance of this problem has yet to gain global attention. Here, we discuss the reports of antifungal resistance from around the world, present our own experience with treatment-resistant infections, and examine alternative treatment strategies. The majority of reports of recalcitrant infections indicate terbinafine resistance as the causative factor. Single-point mutations in the squalene oxidase gene is the most reported mechanism of resistance to terbinafine. Mixed infections of dermatophytes with non-dermatophyte molds and/or yeasts are becoming more prevalent and contributing to the resistant nature of these infections. The key to selecting an effective antifungal therapy for a recalcitrant infection is identification of the infectious organisms(s) and testing susceptibility of the organism(s) to antifungal drugs. Combination and sequential therapy regimens are options, but both require active monitoring for hepatic and renal function, drug interactions, and other adverse effects. Selected topical antifungals with a wide spectrum of activity may also be considerations in some clinical presentations. Innovative treatment regimens and novel therapeutics are needed to overcome the rising epidemic of antifungal resistance.

Intrinsic resistance to terbinafine among human and animal isolates of Trichophyton mentagrophytes related to amino acid substitution in the squalene epoxidase

BACKGROUND

Dermatomycoses are the most common fungal infections in the world affecting a significant part of the human and animal population. The majority of zoophilic infections in humans are caused by Trichophyton mentagrophytes. Currently, the first-line drug for both oral and topical therapy is terbinafine. However, an increasing number of cases that are difficult to be cured with this drug have been noted in Europe and Asia. Resistance to terbinafine and other allylamines is very rare and usually correlated with point mutations in the squalene epoxidase gene resulting in single amino acid substitutions in the enzyme, which is crucial in the ergosterol synthesis pathway.

PURPOSE

Here, we report terbinafine-resistant T. mentagrophytes isolates among which one was an etiological factor of tinea capitis in a man and three were obtained from asymptomatic foxes in Poland.

METHODS

We used the CLSI protocol to determine antifungal susceptibility profiles of naftifine, amphotericin B, griseofulvin, ketoconazole, miconazole, itraconazole, voriconazole, and ciclopirox. Moreover, the squalene epoxidase gene of the terbinafine-resistant strains was sequenced and analysed.

RESULTS

In the genomes of all four resistant strains exhibiting elevated MICs to terbinafine (16 to 32 µg/ml), single-point mutations leading to Leu393Phe substitution in the squalene epoxidase enzyme were revealed. Among the other tested substances, a MIC50 value of 1 µg/ml was shown only for griseofulvin.

CONCLUSION

Finally, our study revealed that the terbinafine resistance phenomenon might not be acquired by exposure to the drug but can be intrinsic. This is evidenced by the description of the terbinafine-resistant strains isolated from the asymptomatic animals.

Tinea corporis: an updated review

Background

Tinea corporis is a common fungal infection that mimics many other annular lesions. Physicians must familiarize themselves with this condition and its treatment.

Objective

This article aimed to provide a narrative updated review on the evaluation, diagnosis, and treatment of tinea corporis.

Methods

A PubMed search was performed with Clinical Queries using the key term ‘tinea corporis.’ The search strategy included clinical trials, meta-analyses, randomized controlled trials, observational studies, and reviews. The search was restricted to the English language. The information retrieved from the mentioned search was used in the compilation of the present article.

Results

Tinea corporis typically presents as a well-demarcated, sharply circumscribed, oval or circular, mildly erythematous, scaly patch or plaque with a raised leading edge. Mild pruritus is common. The diagnosis is often clinical but can be difficult with prior use of medications, such as calcineurin inhibitors or corticosteroids. Dermoscopy is a useful and non-invasive diagnostic tool. If necessary, the diagnosis can be confirmed by microscopic examination of potassium hydroxide wet-mount preparations of skin scrapings from the active border of the lesion. Fungal culture is the gold standard to diagnose dermatophytosis especially if the diagnosis is in doubt and results of other tests are inconclusive or the infection is widespread, severe, or resistant to treatment. The standard treatment of tinea corporis is with topical antifungals. Systemic antifungal treatment is indicated if the lesion is multiple, extensive, deep, recurrent, chronic, or unresponsive to topical antifungal treatment, or if the patient is immunodeficient.

Conclusion

The diagnosis of tinea corporis is usually clinical and should pose no problem to the physician provided the lesion is typical. However, many clinical variants of tinea corporis exist, rendering the diagnosis difficult especially with prior use of medications, such as calcineurin inhibitors or corticosteroids. As such, physicians must be familiar with this condition so that an accurate diagnosis can be made and appropriate treatment initiated.