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Journal of Clinical and Investigative... Dec 2015Seborrheic Dermatitis (SD) and dandruff are of a continuous spectrum of the same disease that affects the seborrheic areas of the body. Dandruff is restricted to the...
Seborrheic Dermatitis (SD) and dandruff are of a continuous spectrum of the same disease that affects the seborrheic areas of the body. Dandruff is restricted to the scalp, and involves itchy, flaking skin without visible inflammation. SD can affect the scalp as well as other seborrheic areas, and involves itchy and flaking or scaling skin, inflammation and pruritus. Various intrinsic and environmental factors, such as sebaceous secretions, skin surface fungal colonization, individual susceptibility, and interactions between these factors, all contribute to the pathogenesis of SD and dandruff. In this review, we summarize the current knowledge on SD and dandruff, including epidemiology, burden of disease, clinical presentations and diagnosis, treatment, genetic studies in humans and animal models, and predisposing factors. Genetic and biochemical studies and investigations in animal models provide further insight on the pathophysiology and strategies for better treatment.
PubMed: 27148560
DOI: 10.13188/2373-1044.1000019 -
Frontiers in Cellular and Infection... 2020Lipophilic yeasts of the genus are important skin commensals and opportunistic skin pathogens in a variety of animals. The species was first isolated from the skin of... (Review)
Review
Lipophilic yeasts of the genus are important skin commensals and opportunistic skin pathogens in a variety of animals. The species was first isolated from the skin of a captive Indian rhinoceros with an exfoliative dermatitis in 1925, recognized as an important otic pathogen of dogs in the 1950's, and finally accepted, after several years of controversy, as a common cause of canine dermatitis in the 1990's. Since then, there has been considerable research into the biology of yeasts and their interaction with their animal hosts. In dogs and cats, is associated with ceruminous otitis externa and a "seborrhoeic" dermatitis, wherein pruritic, erythematous skin lesions, often with brown/black greasy, malodourous material matting hairs, preferentially develop in intertriginous areas. Skin disease is favored by folds, underlying hypersensitivity disorders, endocrinopathies, defects of cornification, and in cats, various visceral paraneoplastic syndromes. Diagnosis is based on detecting the yeast in compatible skin lesions, usually by cytology, and observing a clinical and mycological response to therapy. Treatment normally comprises topical or systemic azole therapy, often with miconazole-chlorhexidine shampoos or oral itraconazole or ketoconazole. Management of concurrent diseases is important to minimize relapses. Historically, wild-type isolates from dogs and cats were typically susceptible to azoles, with the exception of fluconazole, but emerging azole resistance in field strains has recently been associated with either mutations or quadruplication of the gene. These observations have prompted increased interest in alternative topical antifungal drugs, such as chlorhexidine, and various essential oils. Further clinical trials are awaited with interest.
Topics: Animals; Antifungal Agents; Cat Diseases; Cats; Dermatitis; Dog Diseases; Dogs; Drug Resistance, Multiple, Fungal; Malassezia; Skin; Zoonoses
PubMed: 32181160
DOI: 10.3389/fcimb.2020.00079 -
Medical Mycology Journal 2022This review describes the changes in yeast species names in the previous decade. Several yeast species have been reclassified to accommodate the "One fungus=One name"... (Review)
Review
This review describes the changes in yeast species names in the previous decade. Several yeast species have been reclassified to accommodate the "One fungus=One name" (1F=1N) principle of the Code. As the names of medically important yeasts have also been reviewed and revised, details of the genera Candida, Cryptococcus, Malassezia, and Trichosporon are described in Section 3, along with the history of name changes. Since the phylogenetic positions of Candida species in several clades have not been clarified, revision of this species has not been completed. Among the species that remain unrevised despite their importance in the medical field, we propose the transfer of six Candida species to be reclassified in the Nakaseomyces clade, including Nakaseomyces glabratus and Nakaseomyces nivalensis.
Topics: Trichosporon; Malassezia; Cryptococcus; Candida; Phylogeny
PubMed: 36450564
DOI: 10.3314/mmj.22.004 -
Journal of the American Academy of... Mar 2024Seborrheic dermatitis (SD) is a common skin disease with signs and symptoms that may vary by skin color, associated medical conditions, environmental factors, and... (Review)
Review
Seborrheic dermatitis (SD) is a common skin disease with signs and symptoms that may vary by skin color, associated medical conditions, environmental factors, and vehicle preference. Diagnosis of SD is based on presence of flaky, "greasy" patches, and/or thin plaques accompanied by erythema of the scalp, face, ears, chest, and groin and is associated with pruritus in many patients. The presentation may vary in different skin types and hyper- or hypopigmentation may occur, with or without erythema and minimal or no scaling. While the pathogenesis is not certain, 3 key factors generally agreed upon include lipid secretion by sebaceous glands, Malassezia spp. colonization, and some form of immunologic dysregulation that predisposes the patient to SD. Treatment involves reducing proliferation of, and inflammatory response to, Malassezia spp. Topical therapies, including antifungal agents and low potency corticosteroids, are the mainstay of treatment but may be limited by efficacy and side effects. Few novel treatments for SD are currently being studied; however, clinical trials assessing the use of topical phosphodiesterase-4 inhibitors have been completed. Improving outcomes in SD requires recognizing patient-specific manifestations/locations of the disease, including increased awareness of how it affects people of all skin types.
Topics: Humans; Dermatitis, Seborrheic; Antifungal Agents; Adrenal Cortex Hormones; Erythema; Malassezia
PubMed: 36538948
DOI: 10.1016/j.jaad.2022.12.017 -
Allergology International : Official... Oct 2018Sweat allergy is defined as a type I hypersensitivity against the contents of sweat, and is specifically observed in patients with atopic dermatitis (AD) and cholinergic... (Review)
Review
Sweat allergy is defined as a type I hypersensitivity against the contents of sweat, and is specifically observed in patients with atopic dermatitis (AD) and cholinergic urticaria (CholU). The allergic reaction is clinically revealed by positive reactions in the intradermal skin test and the basophil histamine release assay by sweat. A major histamine-releasing antigen in sweat, MGL_1304, has been identified. MGL_1304 is produced at a size of 29 kDa by Malassezia (M.) globosa and secreted into sweat after being processed and converted into the mature form of 17 kDa. It induces significant histamine release from basophils of patients with AD and/or CholU with MGL_1304-specific IgE, which is detected in their sera. Patients with AD also show cross-reactivity to MGL_1304-homologs in Malassezia restricta and Malassezia sympodialis, but MGL_1304 does not share cross antigenicity with human intrinsic proteins. Malassezia or its components may penetrate the damaged epidermis of AD lesions and interact with the skin immune system, resulting in the sensitization and reaction to the fungal antigen. As well as the improvement of impaired barrier functions by topical interventions, approaches such as anti-microbial treatment, the induction of tolerance and antibody/substance neutralizing the sweat antigen may be beneficial for the patients with intractable AD or CholU due to sweat allergy. The identification of antigens other than MGL_1304 in sweat should be the scope for future studies, which may lead to better understanding of sweat allergy and therapeutic innovations.
Topics: Antigens, Fungal; Histamine Release; Humans; Hypersensitivity; Malassezia; Sweat
PubMed: 30075993
DOI: 10.1016/j.alit.2018.07.002 -
Life (Basel, Switzerland) Oct 2023This narrative review presents a comprehensive overview of the diagnosis and management of pityriasis versicolor (PV), a common superficial fungal infection caused by... (Review)
Review
This narrative review presents a comprehensive overview of the diagnosis and management of pityriasis versicolor (PV), a common superficial fungal infection caused by the yeast Malassezia. PV is characterised by scaly hypopigmented or hyperpigmented patches, primarily affecting the upper trunk, neck, and upper arms. Regarding commensal interactions, Malassezia utilises nutrient sources without affecting the human host. In cases of pathogenicity, Malassezia can directly harm the host via virulence factors or toxins, or indirectly by triggering damaging host responses. The diagnosis typically relies on recognising characteristic clinical features. Due to the wide variability in its clinical presentation, recognising the differential diagnosis is critical. In this paper, we discuss the clinical differentials, with their dermatoscopic presentation, but also describe a range of helpful diagnostic techniques (microscopy, conventional and ultraviolet-induced fluorescence dermatoscopy, and confocal microscopy). Topical therapies are the primary treatment for PV, encompassing non-specific antifungal agents like sulphur with salicylic acid, selenium sulphide 2.5%, and zinc pyrithione. Additionally, specific topical antifungal medications with either fungicidal or fungistatic properties may also be incorporated into the topical treatment regimen, such as imidazoles, allylamines, and ciclopirox olamine. Systemic therapies might occasionally be used. Patient education and the promotion of good personal hygiene are pivotal to reduce the risk of recurrence. In recurrent cases, particularly during warmer and more humid periods, prolonged prophylaxis with topical agents should be considered.
PubMed: 37895478
DOI: 10.3390/life13102097 -
Microbiome Nov 2017Most studies describing the human gut microbiome in healthy and diseased states have emphasized the bacterial component, but the fungal microbiome (i.e., the mycobiome)...
BACKGROUND
Most studies describing the human gut microbiome in healthy and diseased states have emphasized the bacterial component, but the fungal microbiome (i.e., the mycobiome) is beginning to gain recognition as a fundamental part of our microbiome. To date, human gut mycobiome studies have primarily been disease centric or in small cohorts of healthy individuals. To contribute to existing knowledge of the human mycobiome, we investigated the gut mycobiome of the Human Microbiome Project (HMP) cohort by sequencing the Internal Transcribed Spacer 2 (ITS2) region as well as the 18S rRNA gene.
RESULTS
Three hundred seventeen HMP stool samples were analyzed by ITS2 sequencing. Fecal fungal diversity was significantly lower in comparison to bacterial diversity. Yeast dominated the samples, comprising eight of the top 15 most abundant genera. Specifically, fungal communities were characterized by a high prevalence of Saccharomyces, Malassezia, and Candida, with S. cerevisiae, M. restricta, and C. albicans operational taxonomic units (OTUs) present in 96.8, 88.3, and 80.8% of samples, respectively. There was a high degree of inter- and intra-volunteer variability in fungal communities. However, S. cerevisiae, M. restricta, and C. albicans OTUs were found in 92.2, 78.3, and 63.6% of volunteers, respectively, in all samples donated over an approximately 1-year period. Metagenomic and 18S rRNA gene sequencing data agreed with ITS2 results; however, ITS2 sequencing provided greater resolution of the relatively low abundance mycobiome constituents.
CONCLUSIONS
Compared to bacterial communities, the human gut mycobiome is low in diversity and dominated by yeast including Saccharomyces, Malassezia, and Candida. Both inter- and intra-volunteer variability in the HMP cohort were high, revealing that unlike bacterial communities, an individual's mycobiome is no more similar to itself over time than to another person's. Nonetheless, several fungal species persisted across a majority of samples, evidence that a core gut mycobiome may exist. ITS2 sequencing data provided greater resolution of the mycobiome membership compared to metagenomic and 18S rRNA gene sequencing data, suggesting that it is a more sensitive method for studying the mycobiome of stool samples.
Topics: Candida; Cohort Studies; DNA, Ribosomal Spacer; Feces; Fungi; Gastrointestinal Microbiome; Genetic Variation; Healthy Volunteers; High-Throughput Nucleotide Sequencing; Humans; Malassezia; Metagenomics; Microbiota; Mycobiome; RNA, Ribosomal, 18S; Saccharomyces; Sequence Analysis, DNA
PubMed: 29178920
DOI: 10.1186/s40168-017-0373-4 -
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 -
Current Fungal Infection Reports 2023To review recent literature on folliculitis and explore its association with COVID-19. (Review)
Review
PURPOSE OF REVIEW
To review recent literature on folliculitis and explore its association with COVID-19.
RECENT FINDINGS
Reports of folliculitis in the setting of COVID-19 are scarce. Shared characteristics between affected individuals include male sex, obesity, intensive care, and administration of systemic antibiotics and systemic steroids. Dexamethasone can potentially stimulate sebum production and therefore lead to proliferation. The clinical picture of folliculitis accompanying COVID-19 is similar to classic descriptions but tends to spare the face and predominates in occlusion sites.
SUMMARY
folliculitis is under-recognized. Fever, sweating, occlusion, immobility, antibiotics, and dexamethasone contribute to COVID-19 patients developing folliculitis. Antifungal therapy, together with correcting predisposing factors, is the mainstay of management. Future research should explore the relationship between systemic steroids and other acneiform reactions.
PubMed: 36741270
DOI: 10.1007/s12281-023-00450-8