An update on antifungal resistance in dermatophytosis

INTRODUCTION

The reports of resistance to antifungal agents used for treating onychomycosis and other superficial fungal infections are increasing. This rise in antifungal resistance poses a public health challenge that requires attention.

AREAS COVERED

This review explores the prevalence of dermatophytes and the current relationship between dermatophyte species, their minimum inhibitory concentrations (MICs) for terbinafine (an allylamine) and itraconazole (an azole), and various mutations prevalent in these species. The most frequently isolated dermatophyte associated with resistance in patients with onychomycosis and dermatophytosis was T. mentagrophytes. However, T. indotineae emerged as the most prevalent isolate with mutations in the SQLE gene, exhibiting the highest MIC of 8 µg/ml for terbinafine and MICs of 8 µg/ml and ≥ 32 µg/ml for itraconazole.Overall, the most prevalent SQLE mutations were Phe397Leu, Leu393Phe, Ala448Thr, Phe397Leu/Ala448Thr, and Lys276Asn/Leu415Phe (relatively recent).

EXPERT OPINION

Managing dermatophyte infections requires a personalized approach. A detailed history should be obtained including details of travel, home and occupational exposure, and clinical examination of the skin, nails and other body systems. Relevant testing includes mycological examination (traditional and molecular). Additional testing, where available, includes MIC evaluation and detection of SQLE mutations. In case of suspected terbinafine resistance, itraconazole or voriconazole (less commonly) should be considered.

Clinico-Demographic Parameters of Oral Fungal Infections: An Institutional Retrospective Study

Introduction Most fungal infections are responsive to antifungal therapy. However, failure to diagnose the same can significantly affect the quality of lives of patients. Timely identification of fungal infections and their association with varied demographic and clinical parameters will help in improving the prognosis of the patient. The present study aims to evaluate the prevalence of fungal infections among various age groups and genders and also to evaluate the association of fungal infections with demographic parameters. Methods This study included a sample size of n = 600. The demographic and clinical details were compiled and transferred to IBM SPSS Version 23 software (IBM Corp., Armonk, NY) for statistical analysis. Descriptive and Pearson chi-square tests were used to analyze the association of the type of fungal infection with gender, age, and comorbidities. A p-value of less than 0.05 is considered statistically significant. Results Angular cheilitis (40%, 240), followed by denture stomatitis (37.5%, 225), were the most common type of fungal infection among the sample population, and the elderly age group (51-72 years) was the most affected. Angular cheilitis was the most common infection among both males (21.4%, 128) and females (18.6%, 112), but candidiasis was reported more in females (18%, 108) than males (3%, 18) (p = 0.00). Angular cheilitis (32%, 192) and candidiasis (18%, 108) were more observed in association with anemia; however, denture stomatitis (34%, 204) was significantly higher among diabetics (p = 0.00). Conclusion The identification of associated systemic and demographic factors is as important as the treatment of fungal infection itself. The recognition of fungal infections and the role of parameters like age, gender, and systemic comorbidities in the development of fungal infections will have valuable implications for public health. Future research is required for a clear understanding of the same.

The Optimal Dosing Regimen of Super Bioavailable Itraconazole in Obesity: An Experimental Rat Model Study

Background Obesity may alter tissue distribution and clearance of several drugs, especially lipophilic ones. Itraconazole, a lipophilic drug, has been recently introduced in a super-bioavailable formulation (SB-ITZ) for the treatment of dermatophytosis. Evidence regarding optimal dosing of SB-ITZ in obesity is lacking. A current experimental study was planned to analyze tissue concentrations of SB-ITZ at different doses in obese and non-obese rats.  Materials and methods Thirty-six Wistar albino rats of either sex were divided into obese and non-obese rats equally. Further, rats in both categories were divided into three dosing groups. Group 1 received SB-ITZ 13 mg once daily in the morning, group 2 received SB-ITZ 13 mg in the morning and 6.5 mg in the evening, while Group 3 rats received SB-ITZ 13 mg twice daily, orally. Concentrations of SB-ITZ in the skin, serum, and fatty tissue were assessed in each group on days 7, 14, 21, and 28. Comparison of SB-ITZ concentrations in various tissues in obese and non-obese rats and inter-group comparison of tissue concentrations across the three dosing regimens was done at day 28 and expressed as Mean ± SD.36 Wistar rats were divided into obese and non-obese rats equally. Results At day 28, skin concentrations of SB-ITZ were 5.36±1.1, 8.9±1.7 and 10.13±1.7 µg/g in Groups 1, 2, and 3, respectively, in non-obese rats, which was statistically significant (p<0.05) than skin concentration of obese rats (2.72±0.6, 4.2±0.7 and 4.66±0.5 µg/g) for the corresponding dosing groups respectively. Skin concentration of SB-ITZ was statistically significant for Groups 2 and 3 as compared to Group 1. Still, no statistically significant difference was noted between Groups 2 and 3 in non-obese and obese rats. Fatty tissue concentration of SB-ITZ was comparable in all 3 dosing regimens in non-obese and obese rats. But on the intergroup comparison, a statistically significant difference was observed for Groups 2 and 3 against Group 1 (p<0.05). Increasing the dose of SB-ITZ increased serum concentration. In non-obese rats, a statistically significant difference was noted between Group 2 (74.33±6.6 ng/ml) and Group 1 (52.5±9.9 ng/ml); p<0.01 and also in Group 3 (81.33±6.8 ng/ml) against Group 1; p<0.01. Group 3 achieved significantly higher concentration than the other two groups in obese rats (Group 3; 72±5.3, Group 2; 60.5±4.3, and Group 1; 45±7 ng/ml; p<0.01). Conclusion Overall, skin, fatty tissue, and serum concentrations of SB-ITZ were higher in non-obese rats compared to obese rats in all three dosing groups. Moreover, skin and fatty tissue concentrations were proportionately higher than serum in all the groups in non-obese and obese rats. Though the skin concentration of non-obese rats was significantly higher than obese rats, skin concentration in obese rats was within the minimum inhibitory concentration (MIC) range, demonstrating the efficacy of all dosing regimens.

Apolipoprotein E Gene Polymorphism, Serum Lipids, and Risk of Superficial Fungal Infections in Egyptian Patients - A Preliminary Case-Controlled Study

Background

Apolipoprotein E (APOE) gene isoforms have been found to affect the risk of superficial fungal infections (SFIs). However, the data only cover a few ethnicities.

Aims

The present work intended to investigate the association of APOE gene polymorphism and serum lipids with the susceptibility of SFIs among a group of Egyptian patients.

Materials and Methods

Standard laboratory methods were used to estimate the serum lipid profile, and polymerase chain reaction-restriction fragment length polymorphism was used to detect APOE gene polymorphism in deoxyribonucleic acid extracted from 150 SFI patients and an equal number of apparently healthy matched controls.

Results

Serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol were significantly higher in the studied patients than in controls. The APOE gene ε2, ε4 alleles, and ε3/4 and ε3/2 genotypes were significantly distributed in the patients than in the controls. APOE ε3/3 genotype was predominant in dermatophytosis and tinea versicolour patients, and ε3/4 genotype was predominant in candidiasis.

Conclusions

ApoE alleles ε2 and ε4, and genotypes ε2/3 and ε3/4 are linked to SFI and may be risk factors, whereas allele ε3 and genotype ε3/3 may be protective for SFI in the Egyptian population studied. The lipid profile results suggest that hyperlipidemia may provide evidence for SFI pathogenesis. However; further large-scale studies are still needed to validate our results.

Factors responsible for difficult to treat superficial fungal infections: A study from a tertiary healthcare centre in India

BACKGROUND

Recurrent and clinically unresponsive dermatophytosis is being increasingly observed in India. However, there is little information regarding the extent of the problem and the factors responsible for these difficult to treat superficial fungal infections.

AIM

To identify factors contributing to difficult to treat recurrent superficial fungal infections.

MATERIALS AND METHODS

This prospective cross-sectional study enrolled 105 patients of all age groups presenting with either recurrent or long-standing dermatophyte infection attending the outpatient department of Dermatology, Venerology and Leprosy of Bharati Hospital, Pune, India, between September 2018 and March 2020. Patients were clinically examined, clinical history was taken and questions were asked regarding their current complaints and recorded in a proforma. Data were analysed using the SPSS software package.

RESULTS

The males outnumbered females (74.3% vs 25.7%). A strong association was observed between the presence of past history and duration of disease (p = .007). The association of use of topical steroids or keratolytic agents with the duration of disease was statistically significant (p = .022). There was a statistically significant inverse association of duration of disease with dermatologist consultation (p < .001). The association between consultation with non-dermatologist and the duration of disease was statistically significant (p = .035).

CONCLUSION

Hyperhidrosis, obesity, positive family history, tight clothing and chronic diseases may be considered important factors in acquiring dermatophytic infection. However, when it comes to difficult to treat tinea infections, irrational usage of topical steroids, treatment from non-dermatologists and a past history of tinea appear to be more critical causative factors. Treatment of dermatophytosis by dermatologists/ trained physicians and increasing general awareness of the public regarding the current situation about tinea in the country would help to alleviate the current crisis.

Dermatological diseases presented before COVID-19: Are patients with psoriasis and superficial fungal infections more vulnerable to the COVID-19?

Recent studies have focused on the comorbid conditions of the COVID‐19. According to the current studies, numerous diseases including lung disease, cardiovascular disease and immunosuppression appear to be at higher risk for severe forms of the COVID‐19. To date, there are no data in the literature on the comorbid dermatologic diseases and COVID‐19. We tried to analyze the previous dermatological comorbidity of 93 patients with COVID‐19 (51 males, 42 females) who presented to the dermatology outpatient clinics for the last 3 years. The most common dermatologic diseases in patients with COVID‐19 who have dermatologic diseases for the last 3 years were superficial fungal infections (24, 25.8%), seborrheic dermatitis (11, 11.8%), actinic keratosis (10, 10.8%), psoriasis (6, 6.5%), and eczema (6, 6.5%), respectively. In addition, the number of COVID‐19 patients who presented to dermatology in the last 3 months was 17 (11 men, 6 women). The median age of these patients was 58 (minimum 18, maximum 80) years, and the most common dermatologic diseases before diagnosed COVID‐19 were superficial fungal infections (5, 25%), psoriasis (4, 20%), and viral skin diseases (3, 15%). The possible similarity between cutaneous and mucosal immunity and immunosuppression suggests that patients with some dermatologic diseases especially superficial fungal infections and psoriasis may be more vulnerable to the COVID‐19.

Superficial fungal infections in the department of dermatology, University Hospital Jena: A 7-year retrospective study on 4556 samples from 2007 to 2013

BACKGROUND

Superficial fungal infections are often seen in day-to-day clinical practice, and their prevalence continues to rise worldwide. Over the years, a change in the pattern of dermatophytoses has been noted.

OBJECTIVES

This study aimed to determine the epidemiologic profile of dermatophytes at the Department of Dermatology, University Hospital Jena, from 2007 to 2013.

METHODS

The retrospective study was carried out with a total of 4556 samples collected from 3607 patients suspected of superficial fungal infections during the 7-year study period.

RESULTS

Among the 3607 suspected patients, 1951 (54.09%) were men and 1656 (45.91%) were women. Of 4556 samples, 703 (15.43%) samples were positive for fungal culture, which included 585 (83.21%) dermatophytes and 118 (16.79%) non-dermatophytes. Trichophyton (T.) rubrum was the most common isolated pathogen in 73.33% of the dermatophyte cases. Among dermatophyte-infected patients, men were most likely to be affected (63.48%) as well as those of higher age (61 to 80). The most commonly affected areas were nails (33.16%) and feet (33%). T rubrum was recurrently isolated in several regions with exception of the scalp where M canis (58.33%) was the most frequently isolated pathogen. About 16.04% of cases had a history of treatment taken prior to sampling. The majority of the affected individuals did not have any prior animal contact (77.26%). T benhamiae was exclusively associated with contact to guinea pigs.

CONCLUSION

Trichophyton rubrum was the most frequently isolated pathogen in several regions except the scalp. New dermatophyte species emerged with time especially T benhamiae.

Green synthesis of silver nanoparticles using Zingiber officinale and Thymus vulgaris extracts: characterisation, cell cytotoxicity, and its antifungal activity against Candida albicans in comparison to fluconazole

Fluconazole (FLZ) application as a highly successful commercial antifungal azole agent to treat the fungal infections is limited due to emergence of FLZ-resistant candida. In this study, the potential of green synthesised silver nanoparticles (NPs) as an antifungal agent against Candida albicans fungal pathogen is investigated. The extract of ginger (Zingiber officinale) and thyme (Thymus vulgaris) plays as reducing agent, capping agent and antifungal agent. The UV-visible spectroscopy shows the peak of surface plasmon resonance of synthesised Ag NPs after a period of time. The synthesised Ag NPs are spherical, with average sizes of 12 and 18 nm based on ginger and thyme extract, respectively. Fourier transform infrared spectroscopy confirms the adsorption of the plant extract on the surface of the as-prepared Ag NPs. Based on the minimum inhibitory concentration (MIC) method against Candida albicans, the antifungal activity of as-prepared green synthesised Ag NPs shows higher inhibitory in comparison to FLZ. Finally, the Ag NPs synthesised via thyme extract shows no cytotoxicity with concentration below 3.5 ppm, which can be considered as an appropriate candidate instead of FLZ to treat the superficial fungal infections.

Risk factors associated with acquiring superficial fungal infections in school children in South Western Nigeria: a comparative study

INTRODUCTION

Superficial fungal infections (SFI) are caused mainly by dermatophytes and yeasts. SFI is of major public health concern and is a common cause of skin disease among school children.

OBJECTIVES

The aim of this study was to identify the risk factors associated with acquiring superficial fungal infections in school children in Ile-Ife, South West Nigeria as this will assist in instituting appropriate interventions.

METHODS

A total of 560 children; 280 with superficial fungal infections as subjects and 280 age and sex matched school children as controls were recruited through multistage sampling method from 10 primary schools (private and public owned) in Ile-Ife, Nigeria.

DISCUSSION

Pupils were aged 5-16 years with a mean age of 9.42±2.00. Risk factors documented in this study included poor living conditions, use of barbers' clippers, low socio-economic status, poor hygiene, attendance of public schools and not living with both parents. The last four factors remained significant on binary logistic regression.

CONCLUSION

The study shows that the risk for acquiring superficial fungal infections remains high in school children and in communities with low socio-economic positions.

Efficacy and safety of itraconazole use in infants

BACKGROUND

Itraconazole has been used to treat fungal infections, in particular invasive fungal infections in infants or neonates in many countries.

DATA SOURCES

Literature search was conducted through Ovid EMBASE, PubMed, ISI Web of Science, CNKI and Google scholarship using the following key words: "pediatric" or "infant" or "neonate" and "fungal infection" in combination with "itraconazole". Based on the literature and our clinical experience, we outline the administration of itraconazole in infants in order to develop evidence-based pharmacotherapy.

RESULTS

Of 45 articles on the use of itraconazole in infancy, 13 are related to superficial fungal infections including tinea capitis, sporotrichosis, mucosal fungal infections and opportunistic infections. The other 32 articles are related to systemic fungal infections including candidiasis, aspergillosis, histoplasmosis, zygomycosis, trichosporonosis and opportunistic infections as caused by Myceliophthora thermophila.

CONCLUSION

Itraconazole is safe and effective at a dose of 5 mg/kg per day in a short duration of therapy for superficial fungal infections and 10 mg/kg per day for systemic fungal infections in infants. With a good compliance, it is cost-effective in treating infantile fungal infections. The profiles of adverse events induced by itraconazole in infants are similar to those in adults and children.

Management of tinea corporis, tinea cruris, and tinea pedis: A comprehensive review

The prevalence of superficial mycotic infection worldwide is 20–25% of which dermatophytes are the most common agents. Recent developments in understanding the pathophysiology of dermatophytosis have confirmed the central role of cell-mediated immunity in countering these infections. Hence, a lack of delayed hypersensitivity reaction in presence of a positive immediate hypersensitivity (IH) response to trichophytin antigen points toward the chronicity of disease. Diagnosis, though essentially clinical should be confirmed by laboratory-based investigations. Several new techniques such as polymerase chain reaction (PCR) and mass spectroscopy can help to identify the different dermatophyte strains. Management involves the use of topical antifungals in limited disease, and oral therapy is usually reserved for more extensive cases. The last few years have seen a significant rise in the incidence of chronic dermatophyte infections of skin which have proven difficult to treat. However, due to the lack of updated national or international guidelines on the management of tinea corporis, cruris, and pedis, treatment with systemic antifungals is often empirical. The present review aims to revisit this important topic and will detail the recent advances in the pathophysiology and management of tinea corporis, tinea cruris, and tinea pedia while highlighting the lack of clarity of certain management issues.