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Clinical Microbiology Reviews Apr 1995The etiologic agents of the dermatophytoses (ringworm) are classified in three anamorphic (asexual or imperfect) genera, Epidermophyton, Microsporum, and Trichophyton.... (Review)
Review
The etiologic agents of the dermatophytoses (ringworm) are classified in three anamorphic (asexual or imperfect) genera, Epidermophyton, Microsporum, and Trichophyton. Species capable of reproducing sexually belong in the teleomorphic genus, Arthroderma, of the Ascomycota. On the basis of primary habitat association, they may be grouped as geophilic (soil associated), zoophilic, and anthropophilic. Adaptation to growth on humans by most geophilic species resulted in diminished loss of sporulation, sexuality, and other soil-associated characteristics. The dermatophytes have the ability to invade keratinized tissue (skin, hair, and nails) but are usually restricted to the nonliving cornified layer of the epidermis because of their inability to penetrate viable tissue of an immunocompetent host. However, invasion does elicit a host response ranging from mild to severe. Acid proteinases, elastase, keratinases, and other proteinases reportedly act as virulence factors. The development of cell-mediated immunity correlated with delayed hypersensitivity and an inflammatory response is associated with clinical cure, whereas the lack of or a defective cell-mediated immunity predisposes the host to chronic or recurrent dermatophyte infection. Chronic dermatophytosis is mostly caused by Trichophyton rubrum, and there is some evidence that mannan produced by this fungus suppresses or diminishes the inflammatory response. Since dermatophytes cause a communicable disease, modes of transmission and control are discussed as well as a survey of recent trends in therapy. Collection of specimens, culture media, and tests for identification are also presented. Genetic studies have led to an understanding of incompatibility mechanisms, pleomorphism and variation, resistance to griseofulvin, and virulence. Molecular biology has contributed to our knowledge of the taxonomy and phylogenetic relationships of dermatophytes.
Topics: Antigens, Fungal; Arthrodermataceae; Chronic Disease; Dermatomycoses; Endopeptidases; Humans; Immunity, Cellular; Phylogeny; Trichophyton; Virulence
PubMed: 7621400
DOI: 10.1128/CMR.8.2.240 -
Journal of Fungi (Basel, Switzerland) Sep 2021Dermatophytes are the most common cause of fungal infections worldwide, affecting millions of people annually. The emergence of resistance among dermatophytes along with... (Review)
Review
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% spp., 29% spp., and 2% ). 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.
PubMed: 34575765
DOI: 10.3390/jof7090727 -
Veterinary World Jun 2020Dermatophytosis, a zoonotic disease, is caused by fungi of three main genera, namely, , and . Specific lesions of dermatophyte infections are localized in the face,... (Review)
Review
Dermatophytosis, a zoonotic disease, is caused by fungi of three main genera, namely, , and . Specific lesions of dermatophyte infections are localized in the face, legs, and/or tail. Skin lesions in infected animals demonstrate localized alopecia, erythema, and crust, which are more commonly known as ringworm. Factors that affect dermatophytosis include the dermatophyte species; virulence factors of the agent; and the immune status, age, and sex of the host. High levels of cortisol and pro-inflammatory cytokines have also been reported to play an important role in dermatophyte infection. This review aims to explore and understand factors that affect dermatophyte infection with an emphasis on the prevalence, clinical signs, pathogenesis, immune response, and the roles of cortisol and cytokines in companion animals infected by a dermatophyte.
PubMed: 32801570
DOI: 10.14202/vetworld.2020.1174-1181 -
British Medical Journal Jul 1968Fourteen cases are described in which the local application of corticosteroid preparations to ringworm infections of the skin have resulted in unusual clinical pictures....
Fourteen cases are described in which the local application of corticosteroid preparations to ringworm infections of the skin have resulted in unusual clinical pictures. A kerion-like lesion due to Trichophyton rubrum, intertriginous infections simulating candidiasis and due to Epidermophyton floccosum, and pictures resembling poikiloderma, papular rosacea, and indeterminate leprosy are among the changes that were seen in these patients.
Topics: Adolescent; Adult; Aged; Betamethasone; Diagnosis, Differential; Eczema; Epidermophyton; Female; Fluocinolone Acetonide; Glucocorticoids; Griseofulvin; Humans; Keratins; Male; Middle Aged; Skin Diseases; Tinea; Triamcinolone Acetonide; Trichophyton; Valerates
PubMed: 5662546
DOI: 10.1136/bmj.3.5611.149 -
Frontiers in Microbiology 2021Dermatophytes are a group of molds characterized by the ability to produce keratinases, thereby carving out for themselves specific ecological niches. Their traditional... (Review)
Review
INTRODUCTION
Dermatophytes are a group of molds characterized by the ability to produce keratinases, thereby carving out for themselves specific ecological niches. Their traditional division into three genera, , , and has been expanded to nine and the species in each genus were modified. Dermatophytes are among the most prevalent causes of human and animal mycoses. Their epidemiology is influenced by various factors. These factors may be evolutive such as the predilected environment of the fungus, namely, humans (anthropophilic), animals (zoophilic), or environment (geophilic), is evolutionary and thus may require centuries to develop. Many other factors, however, result from a variety of causes, affecting the epidemiology of dermatophytoses within a shorter time frame.
OBJECTIVE
This review aims at summarizing the factors that have modified the epidemiology of dermatophytoses during the last decades.
RESULTS
Geographic and climatic conditions, demography such as age and gender, migration, socio-economic conditions, lifestyle, and the environment have had an impact on changes in the epidemiology of dermatophytoses, as have changes in the pattern of human interaction with animals, including pets, farm, and wild animals. A typical example of such changes is the increased prevalence of , which spread from Latin America to the United States and subsequently becoming a frequent etiological agent of tinea capitis in Africa, Middle East, and other areas.
CONCLUSION
The comprehension of the epidemiology of dermatophytoses has a major bearing on their prevention and treatment. Since it is undergoing continuous changes, periodic assessments of the most recent developments of this topic are required. This article aims at providing such an overview.
PubMed: 34421872
DOI: 10.3389/fmicb.2021.713532 -
Mycopathologia Oct 2016Diapers create particular conditions of moisture and friction, and with urine and feces come increased pH and irritating enzymes (lipases and proteases). Fungi can take... (Review)
Review
Diapers create particular conditions of moisture and friction, and with urine and feces come increased pH and irritating enzymes (lipases and proteases). Fungi can take advantage of all these factors. Candida yeasts, especially C. albicans, are responsible for the most frequent secondary infections and are isolated in more than 80 % of cases. Correct diagnosis is important for ensuring the correct prescription of topical antimycotics. Nystatin, imidazoles and ciclopirox are effective. It is important to realize there are resistant strains. Dermatophytes can infect the diaper area, with the most common agent being Epidermophyton floccosum. The clinical characteristics of dermatophytosis are different from those of candidiasis, and it can be diagnosed and treated simply. Malassezia yeasts can aggravate conditions affecting the diaper area, such as seborrheic dermatitis, atopic dermatitis, and inverse psoriasis. Additional treatment is recommended in this case, because they usually involve complement activation and increased specific IgE levels. Erythrasma is a pseudomycosis that is indistinguishable from candidiasis and may also occur in large skin folds. It is treated with topical antibacterial products and some antimycotics.
Topics: Antifungal Agents; Dermatitis, Contact; Dermatomycoses; Fungi; Humans
PubMed: 27193417
DOI: 10.1007/s11046-016-0020-9 -
Actas Dermo-sifiliograficas Mar 2008Tinea capitis is a widespread scalp infection in children caused by dermatophytes. In fact, it is the most common cutaneous mycosis in children but is uncommon in... (Review)
Review
Tinea capitis is a widespread scalp infection in children caused by dermatophytes. In fact, it is the most common cutaneous mycosis in children but is uncommon in adults. The disease has been major public health concern for decades. Some factors implicated in infection include poor personal hygiene, crowded living conditions, and low socioeconomic status. It can be caused by any pathogenic dermatophyte except for Epidermophyton floccosum and Trichophyton concentricum. Trichophyton rubrum, the most commonly isolated dermatophyte worldwide, is rarely the causative agent of this infection. Tinea capitis is a classic example of the changing geographic patterns of dermatophytosis. In developed countries, Trichophyton tonsurans is the most common causative agent, whereas in developing countries such as Mexico, the most common agent is Microsporum canis followed by Trichophyton tonsurans. The increasing incidence of tinea capitis warranted a review of the current literature and treatment strategies.
Topics: Antifungal Agents; Humans; Tinea Capitis
PubMed: 18346430
DOI: No ID Found -
American Family Physician May 2008The common dermatophyte genera Trichophyton, Microsporum, and Epidermophyton are major causes of superficial fungal infections in children. These infections (e.g., tinea... (Review)
Review
The common dermatophyte genera Trichophyton, Microsporum, and Epidermophyton are major causes of superficial fungal infections in children. These infections (e.g., tinea corporis, pedis, cruris, and unguium) are typically acquired directly from contact with infected humans or animals or indirectly from exposure to contaminated soil or fomites. A diagnosis usually can be made with a focused history, physical examination, and potassium hydroxide microscopy. Occasionally, Wood's lamp examination, fungal culture, or histologic tissue examination is required. Most tinea infections can be managed with topical therapies; oral treatment is reserved for tinea capitis, severe tinea pedis, and tinea unguium. Topical therapy with fungicidal allylamines may have slightly higher cure rates and shorter treatment courses than with fungistatic azoles. Although oral griseofulvin has been the standard treatment for tinea capitis, newer oral antifungal agents such as terbinafine, itraconazole, and fluconazole are effective, safe, and have shorter treatment courses.
Topics: Administration, Oral; Administration, Topical; Antifungal Agents; Child; Child Welfare; Dose-Response Relationship, Drug; Humans; Risk Factors; Tinea; Tinea Capitis; Tinea Pedis; Trichophyton; United States
PubMed: 18533375
DOI: No ID Found -
Journal of Fungi (Basel, Switzerland) Oct 2021Inflammatory tinea is an uncommon group of dermatophyte entities that predominantly cause fungal infection of the skin and hair. This review intends to present all of... (Review)
Review
PURPOSE OF REVIEW
Inflammatory tinea is an uncommon group of dermatophyte entities that predominantly cause fungal infection of the skin and hair. This review intends to present all of the available evidence regarding its epidemiology, etiopathogenesis, clinical features, and diagnostic methods as well as treatments recommended for various inflammatory tinea infections. This article provides a review of Majocchi's granuloma and dermatophytic or Hadida's disease.
RECENT FINDINGS
The new phylogenetic classification of dermatophytes includes nine genera, and those that affect humans are , , , and . Furthermore, molecular advancements have revealed impaired antifungal immune responses caused by inflammatory tinea, which are detailed in this article.
SUMMARY
The common denominator in these pathologies is the presence of impaired immune responses and, consequently, an impaired inflammatory response by the host. It is necessary to be familiar with these immunological characteristics in order to use the appropriate diagnostic methods and to provide adequate treatment.
PubMed: 34829218
DOI: 10.3390/jof7110929