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Acta Dermatovenerologica Alpina,... Jun 2022Malassezia is a commensal fungus that constitutes normal skin microbiota. However, in certain conditions and individuals, it may transform into a pathogenic yeast with... (Review)
Review
Malassezia is a commensal fungus that constitutes normal skin microbiota. However, in certain conditions and individuals, it may transform into a pathogenic yeast with multiple associated dermatological disorders and various clinical manifestations. This phenomenon is influenced by a unique host-agent interaction that triggers the production of several virulence factors, such as indoles, reactive oxygen species, azelaic acid, hyphae formation, and biofilm formation. This review article discusses Malassezia virulence factors that contribute to the transformation of Malassezia from commensal to pathogenic as well as their role in dermatological disorders, including pityriasis versicolor, seborrheic dermatitis, Malassezia folliculitis, atopic dermatitis, and psoriasis.
Topics: Dermatitis, Seborrheic; Dermatomycoses; Humans; Malassezia; Skin; Tinea Versicolor; Virulence Factors
PubMed: 35751534
DOI: No ID Found -
Medical Mycology Journal 2023Trichophyton tonsurans infection has been prevalent among individuals involved in contact sports in Japan since about 2000. The present review focuses on its diagnosis,... (Review)
Review
Trichophyton tonsurans infection has been prevalent among individuals involved in contact sports in Japan since about 2000. The present review focuses on its diagnosis, molecular epidemiology, drug susceptibility, and infection control. The most commonly observed lesions of T. tonsurans, an anthropogenic dermatophyte, are tinea corporis and tinea capitis. However, the presence of asymptomatic carriers must be considered for infection control. Genotypic epidemiology using restriction fragment length polymorphisms (RFLP) in the non-transcribed spacer (NTS) region of the ribosomal RNA gene showed a lack of diversity of genotypes, and only the NTS I genotype is detected at present. In regard to drug susceptibility, terbinafine drug resistance has not been found to be associated with the RFLP genotypes, and it is assumed that there are no terbinafine-resistant strains in Japan. T. tonsurans coexisted with other fungi and bacteria in the scalp of asymptomatic carriers without affecting species diversity. T. tonsurans is an anthropogenic dermatophyte and may be difficult for the human immune system to eliminate. During an infection outbreak, screening of infection and treatment including asymptomatic carriers are essential to eradicate the infection.
Topics: Humans; Tinea; Tinea Capitis; Genotype
PubMed: 37648498
DOI: 10.3314/mmj.23-001 -
Clinical and Experimental Dermatology Jan 2022A 65-year-old man presented to our hospital with a 1-year history of multiple nodules on his arms and hands without itching or pain.
A 65-year-old man presented to our hospital with a 1-year history of multiple nodules on his arms and hands without itching or pain.
Topics: Agaricales; Aged; Arm; Dermatomycoses; Diagnosis, Differential; Glucocorticoids; Gout; Granuloma; Hand Dermatoses; Humans; Immunocompromised Host; Male; Purpura, Thrombocytopenic, Idiopathic
PubMed: 34289139
DOI: 10.1111/ced.14855 -
Cleveland Clinic Journal of Medicine Oct 2023
Topics: Humans; Tinea
PubMed: 37783500
DOI: 10.3949/ccjm.90a.23002 -
Ugeskrift For Laeger Nov 2020In this review, we discuss Malassezia folliculitis (MF), which is an inflammation in the hair follicles caused by different Malassezia species. The prevalence of MF in... (Review)
Review
In this review, we discuss Malassezia folliculitis (MF), which is an inflammation in the hair follicles caused by different Malassezia species. The prevalence of MF in the population worldwide ranges from 1% to 17%. Clinically, it may be difficult to distinguish from acne vulgaris, as it presents as erythematous 2-4 mm large papules and pustules on the back, chest and neck. Adequate diagnostic methods, including microscopy or biopsy, are essential to confirm the MF diagnosis, and to ensure initiation of the appropriate anti-fungal treatment.
Topics: Acne Vulgaris; Biopsy; Dermatomycoses; Folliculitis; Humans; Malassezia
PubMed: 33215579
DOI: No ID Found -
Veterinary Journal (London, England :... Apr 2024Malassezia are members of the mycobiome of dogs and cats. In the presence of an underlying disease, these yeasts can proliferate, attach to the skin or mucosa to induce... (Review)
Review
Malassezia are members of the mycobiome of dogs and cats. In the presence of an underlying disease, these yeasts can proliferate, attach to the skin or mucosa to induce a secondary Malassezia dermatitis, otitis externa or paronychia. Since allergic dermatitis is one of the most common underlying causes, diagnostic investigation for allergy is often indicated. Cats may suffer from various other underlying problems, especially where Malassezia dermatitis is generalised. Malassezia dermatitis in dogs and cats is chronic, relapsing and pruritic. Direct cytology from dermatological lesions and the ear canal, showing "peanut-shaped" budding yeasts, facilitates a rapid and reliable diagnosis. Topical treatment includes antiseptic and antifungal azole-based products. Systemic treatment with oral antifungals is indicated only in severe or refractory disease. Identification and treatment of the underlying cause is essential for an optimal response. In this evidence-based narrative review, we discuss the clinical presentation of Malassezia dermatitis in dogs and cats, underlying comorbidities, and diagnostic considerations. Treatment is discussed in light of emerging evidence of antifungal resistance and the authors' clinical experience.
Topics: Animals; Cats; Dogs; Malassezia; Dermatomycoses; Cat Diseases; Antifungal Agents; Dog Diseases; Neoplasm Recurrence, Local; Dermatitis
PubMed: 38431127
DOI: 10.1016/j.tvjl.2024.106084 -
The Australasian Journal of Dermatology Aug 2023The incidence and prevalence of recalcitrant cutaneous fungal infections is on the rise. Terbinafine-resistant Trichophyton has not only been widespread in India, but... (Review)
Review
The incidence and prevalence of recalcitrant cutaneous fungal infections is on the rise. Terbinafine-resistant Trichophyton has not only been widespread in India, but has also been reported in countries spread throughout the globe. Strains of yeasts such as Malassezia and Candida, which exist both as commensals and as pathogens to the human skin, have also been found to develop resistance to antifungals. Non-dermatophyte moulds which can colonize and infect damaged nails are especially difficult to treat, not only due to resistance, but also because of poor drug penetration of hard keratin. Psychosocial factors such as the indiscriminate broad-spectrum antifungal use in agriculture and in medicine, and poor adherence to hygienic measures to break the chain of infection contribute to the development of antifungal resistance. Such environments encourage fungi to develop various resistance mechanisms to withstand antifungal treatment. These include: (a) alteration of the drug target, (b) increasing efflux of drug/metabolites, (c) inactivation of drug, (d) bypass mechanisms or substitution of the pathway affected by the drug, (e) stress adaptation mechanisms and (f) biofilm formation. Understanding of such mechanisms and how they arise are crucial for development of new ways to prevent or overcome resistance. Novel antifungal treatments have recently been approved in the United States of America for treatment of vulvovaginal candidiasis. Ibrexafungerp (enfumafungin derivative) and oteseconazole (tetrazole) differ from their respective related drug classes of echinocandins and triazoles by having different structures, which lend these medicines advantage compared to traditional treatment by having a different binding site and more selectivity for fungi respectively. Other drugs designed to circumvent the known mechanisms of antifungal resistance are also at various phases of development. Concurrent measures at an institutional and individual level to address and limit inappropriate antifungal use to reduce development of antifungal resistance should be undertaken in a concerted effort to address this epidemic.
Topics: Female; Humans; Antifungal Agents; Echinocandins; Dermatomycoses; Terbinafine; Candidiasis, Vulvovaginal
PubMed: 37387447
DOI: 10.1111/ajd.14115 -
Mycoses May 2021Dermatophytosis is a skin infection caused by keratinophilic, filamentous fungi. These are highly prevalent, common mycoses, affecting approximately 20% of the... (Review)
Review
Dermatophytosis is a skin infection caused by keratinophilic, filamentous fungi. These are highly prevalent, common mycoses, affecting approximately 20% of the population. These fungi invade the stratum corneum, and other keratinised tissues, like nails and hair, where they grow by secreting enzymes and degrading keratin to obtain nutrients. Clinical presentation is variable and may depend on many factors, such as the infection site, the host's immunity and the dermatophyte's virulence. Generally, patients with acute superficial dermatophytosis mount cell-mediated immune responses. However, those suffering from chronic or recurrent infections are unable to develop this response, for reasons yet unknown. Several reports have described severe and occasionally life-threatening invasive diseases (deep dermatophytosis) associated with genetic mutations in the innate immunity-associated molecule CARD9, displaying the need to better understand its immune response. These dermatoses have substantial clinical consequences, producing chronic and difficult to treat skin lesions. They also lead to a decline in the patient's quality of life and impact their self-esteem. This review summarises findings on the immune response against dermatophytes.
Topics: Adaptive Immunity; CARD Signaling Adaptor Proteins; Dermatomycoses; Hair; Humans; Immunity; Immunity, Cellular; Immunity, Innate; Keratins; Nails; Opportunistic Infections; Skin; Trichophyton
PubMed: 33480106
DOI: 10.1111/myc.13246 -
Microbiology Spectrum Aug 2023The genus comprises lipid-dependent yeasts that have long been associated with common skin diseases, and have recently been linked with Crohn's disease and certain...
The genus comprises lipid-dependent yeasts that have long been associated with common skin diseases, and have recently been linked with Crohn's disease and certain cancers. Understanding susceptibility to diverse antimicrobial agents is crucial for identifying effective antifungal therapies. Here, we tested the efficacy of isavuconazole, itraconazole, terbinafine, and artemisinin against three species: , and . Using broth microdilution, we found antifungal properties for the two previously unstudied antimicrobials: isavuconazole and artemisinin. Overall, all species were particularly susceptible to itraconazole, with a MIC range from 0.007 to 0.110 μg/mL. The genus is known to be involved in a variety of skin conditions and has recently been associated with diseases such as Crohn's disease, pancreatic ductal carcinoma, and breast cancer. This work was completed to assess susceptibility to a variety of antimicrobial drugs on three species, in particular , which is an abundant species both on human skin and internal organs and has been implicated in Crohn's disease. We tested two previously unstudied drugs and developed a new testing method to overcome current limitations for measuring growth inhibition of slow-growing strains.
Topics: Humans; Antifungal Agents; Itraconazole; Malassezia; Crohn Disease; Dermatomycoses; Microbial Sensitivity Tests
PubMed: 37310217
DOI: 10.1128/spectrum.05076-22 -
Der Hautarzt; Zeitschrift Fur... Aug 2019Many dermatologists do not understand the perpetual adjustments in the dermatophyte nomenclature. (Review)
Review
BACKGROUND
Many dermatologists do not understand the perpetual adjustments in the dermatophyte nomenclature.
OBJECTIVES
The aim is to explain the background and the development of methods that have led to previous and current changes of dermatophyte taxonomy and to the detection of new dermatophytes.
METHODS
In this article we evaluate the recent literature on this topic and our own results in the fields of dermatophyte identification, their detection, and of the associated taxonomic developments.
RESULTS
Today, the phylogenetic species concept is the basis of taxonomic classification, including that of dermatophytes. Genetic techniques have decisively advanced this and are state of the art nowadays. The detection of new dermatophyte species was often triggered by clinical observations and by morphologically conspicuous cultures that prompted their subsequent exact mycological characterization. Even today not all species of dermatophytes are unequivocally defined.
CONCLUSIONS
By exclusively using selected genetic characteristics for the construction of phylogenetic trees additional taxonomically relevant features are neglected. Therefore it is necessary to better integrate data derived from morphologic, physiologic, ecologic and pathophysiologic observations into phylogenetic analyses. Dermatologists are still asked to contribute such information.
Topics: Arthrodermataceae; Classification; Dermatomycoses; Humans; Mycological Typing Techniques; Mycology; Phylogeny; Polymorphism, Genetic; Sequence Analysis, DNA; Species Specificity
PubMed: 31098690
DOI: 10.1007/s00105-019-4427-3