Comparative study between topically applied irradiated human amniotic membrane in combination with tea tree oil versus topical tioconazole in pityraisis versicolor treatment.

Pityriasis versicolor (PV) is a chronic skin disease caused by virulence activities of Malassezia, a genus of skin-associated yeasts. Traditionally, Tioconazole is used as a topical antifungal for curing PV. Previous investigations cited that human amniotic membrane (HAM), a placental tissue, has antimicrobial and anti-inflammatory activities and is useful as a dressing for healing skin lesions. Moreover, tea tree oil (TTO) has a potent antifungal efficacy. This clinical trial aims to achieve an alternative therapeutic treatment able to kill Malassezia and heal PV lesions using TTO-saturated HAM (TOSHAM), with little application times. This study subjected 120 patients with hypopigmented or hyperpigmented PV lesions; half patients were treated weekly with TOSHAM compared with the others who applying 1% Tioconazole cream daily as a traditional treatment. Microbiological evaluation of in vitro fungicidal activity of TOSHAM versus Tioconazole was carried out against Malassezia furfur culture. The clinical outcomes of this study proved the superior activity of TOSHAM to heal PV lesions than Tioconazole; this was in harmony with microbiological findings. This study approached a novel therapeutic treatment of PV with great outcomes by using TOSHAM.

Aislamiento e identificación fenotípica y genotípica de cepas de Malassezia spp. en pacientes con pitiriasis versicolor / Isolation and identification phenotypic and genotypic strains of Malassezia spp. in patients with pytiriasis versicolor

Antecedentes: Pitiriasis versicolor (PV) es una infección micótica superficial crónica de la piel, debido a la colonización del estrato córneo por Malassezia sp. Tradicionalmente M. furfur era considerada el agente causal de PV, hoy en día se ha demostrado que las especies de Malassezia más comunes cultivadas a partir de de lesiones de PV son M. globosa y M. sympodialis. Objetivos: Evaluar la epidemiología de la dermatomicosis PV, en pacientes de la ciudad de Talca, Chile. Metodología: En este estudio, 19 pacientes diagnosticados con PV fueron evaluados. Se realizó identificación fenotípica e identificación molecular por técnica de PCR-RFLP. Para esto, se diseñaron partidores que amplificaron una zona del 26S ADNr presente en todas las especies de Malassezia. Resultados: De un total de 19 pacientes con PV, 7 correspondieron a sexo masculino (36,8 por ciento) y 12 a sexo femenino (63,2 por ciento). Se obtuvieron 18 cepas, a partir de las pruebas fenotípicas fue posible identificar presuntivamente 11 especies de M. globosa (61,1 por ciento) y 7 especies de M. sympodialis (38,9 por ciento). Con los resultados obtenidos en la PCR-RFLP fue posible identificar 11 especies de M. globosa (61,1 por ciento) y 7 especies (38,9 por ciento) de M. sympodialis. Conclusiones: La especie identificada fenotípicamente y molecularmente en mayor proporción fue Malassezia globosa seguida de Malassezia sympodialis. Por lo que hay concordancia entre ambas técnicas de identificación. Este es el primer trabajo de investigación realizado en Talca, Chile, que identificó las especies de Malassezia spp. involucradas en PV, siendo un aporte al estudio de este cuadro clínico.

Background: Pytiriasis versicolor (PV) is a fungal infection of the skin due to the stratum corneum colonization by Malassezia sp. M. furfur traditionally was considered the etiological agent of PV but today it has been shown that M. globosa and M. sympodialis are the most common Malassezia species cultivated from PV lesions. Objective: To evaluate the epidemiological features of PV in patient of the Talca city, Chile. Method: In this study, 19 patients with diagnosis of PV were evaluated. Phenotypic and molecular identified were performed using PCR-RFLP. To do this, primers to amplify 26S ADNr secuence were designed. Result: From a total of 19 patients who presented PV, 7 were male (36.8 percent) and 12 female patients (63.2 percent). Eighteen strains were obtained, from the phenotypic tests, it was possible to presumably identify 11 species of M. globosa (61.1 percent) and 7 species of M. sympodialis (38.9 percent). With PCRRFLP results it was possible to identify 11 species of M. globosa (61.1 percent) and 7 species (38.9 percent) of M. sympodialis. Conclusion: The most commonly isolated species were Malassezia globosa followed by Malassezia sympodialis. So, there is agreement between both techniques of identification. This is the first research work carried out in Talca, Chile, which identified the species of Malassezia spp. Involved in PV, being a contribution to the clinical diagnosis.

Dermatophytes and other associated fungi in patients attending to some hospitals in Egypt

Dermatophytes are keratinophilic fungi that infect keratinized tissues causing diseases known as dermatophytoses. Dermatophytes are classified in three genera, Epidermophyton, Microsporum, and Trichophyton. This investigation was performed to study the prevalence of dermatomycosis among 640 patients being evaluated at the dermatology clinics at Kasr elainy, El-Husein and Said Galal hospitals in Cairo and Giza between January 2005 and December 2006. The patients were checked for various diseases. Tinea capitis was the most common clinical disease followed by tinea pedis and tinea corporis. Tinea cruris and tinea unguium were the least in occurrence. Tinea versicolor also was detected. The most susceptible persons were children below 10 years followed by those aged 31–40 years. Unicellular yeast was the most common etiological agent and T. tonsuranswas the second most frequent causative agent followed by M. canis.

Malassezia infections: a medical conundrum.

Malassezia yeasts have long been considered commensal fungi, unable to elicit significant damage. However, they have been associated with a diversity of cutaneous diseases, namely pityriasis versicolor, Malassezia folliculitis, seborrheic dermatitis, atopic dermatitis, psoriasis, and confluent and reticulate papillomatosis. Several hypotheses have been proposed to explain the pathogenic mechanisms of these fungi, but none have been confirmed. More recently, such organisms have been increasingly isolated from bloodstream infections raising serious concern about these fungi. Given the difficulty to culture these yeasts to proceed with speciation and antimicrobial susceptibility tests, such procedures are most often not performed and the cutaneous infections are treated empirically. The recurring nature of superficial skin infections and the potential threat of systemic infections raise the need of faster and more sensitive techniques to achieve isolation, identification, and antimicrobial susceptibility profile. This article reviews and discusses the latest available data concerning Malassezia infections and recent developments about diagnostic methods, virulence mechanisms, and susceptibility testing.

Tinea versicolor in dark-skinned individuals.

In this article, we review the salient features of tinea versicolor and describe the epidemiology, clinical presentation, and histopathology of this mycosis in dark-skinned individuals. Tinea versicolor is caused by an overgrowth of the Malassezia genus. It manifests clinically as asymptomatic hypopigmented macules, hyperpigmented macules, or a combination of the two. Under light microscopy, Malassezia presents as a dimorphic fungus - in both the hyphal and yeast form. Most clinicians have found that the majority of dark-skinned patients present solely with hypopigmented lesions. Under light microscopy, lesions on dark skin involved with tinea versicolor tend to have a thicker stratum corneum, more tonofilaments in the granulosum, and more sequestered melanosomes. Differential diagnosis includes confluent and reticulated papillomatosis, seborrheic dermatitis, pityriasis rosea, pityriasis alba, and vitiligo. Tinea versicolor can be successfully managed in most cases with topical antifungal treatments. Cases of recurrence, such as those seen in immunocompromised patients, may necessitate scheduled oral or topical therapy.

Identificação de espécies de malassésia na pitiríase versicolor em um serviço de dermatologia do sul do Brasil / Identification of Malassezia yeast species isolated from patients with pityriasis versicolor

A pitiríase versicolor é uma doença de distribuição universal. Existe a descrição de 12 espécies de malassezia. O objetivo deste estudo foi determinar quais as espécies de malassezia mais prevalentes nos pacientes com pitiríase versicolor. Foram realizadas as coletas através de raspado das lesões nos pacientes com suspeita clínica de pitiríase versicolor e posterior exame micológico e cultural para identificação final da espécie. Foram coletadas amostras de 87 pacientes. Quanto às culturas, 30 percent foram de Malassezia sympodialis, 25,7 percent de Malassezia furfur, 22,7 percent de Malassezia globosa, 12,1 percent de Malassezia retrita, 7,6 percent de Malassezia obtusa e 1,5 percent de Malassezia sloofiae.

Pityriasis versicolor (PV) is a disease with worldwide distribution. Twelve different species of Malassezia yeast have been described. The objective of this study was to determine which species of Malassezia are more prevalent in patients with pityriasis versicolor. Samples were collected by scraping the lesions of 87 patients with a clinical suspicion of pityriasis versicolor. The samples were then submitted to fungal microscopy and culture to identify the species. The species found were: Malassezia sympodialis (30 percent), Malassezia furfur (25.7 percent), Malassezia globosa (22.7 percent), Malassezia restricta (12.1 percent), Malassezia obtusa (7.6 percent) and Malassezia slooffiae (1.5 percent).

Malassezia virulence determinants.

PURPOSE OF REVIEW: Malassezia yeasts are associated with a number of dermatologic and systemic diseases in humans and animals. Pityriasis versicolor is amongst these diseases and represents one of the most common human skin diseases. Beyond that, the role of Malassezia yeasts in the pathogenesis of other skin diseases such as psoriasis, seborrheic dermatitis and confluent and reticulate papillomatosis is discussed but remains less clear. Clear pathogenetic mechanisms of the above-mentioned diseases are not known so far. The review presents new findings on virulence factors of Malassezia yeasts, shedding light on the pathogenesis of Malassezia-associated diseases. RECENT FINDINGS: Several virulence factors in Malassezia yeasts are known, based on their enzymatic lipolytic activity resulting in the production of distinct metabolites and special cell wall features. Recently, a secondary metabolic pathway possibly implicated in the pathogenesis of pityriasis versicolor was described. SUMMARY: The article presents virulence factors of Malassezia yeasts ranging from irritant metabolic byproducts to highly bioactive indole derivatives and attempts to clarify their pathogenic implications in the different diseases. Special emphasis is given to the pathogenesis of pityriasis versicolor, as it represents the disease wherein the causative relationship with Malassezia yeasts appears the most obvious.

Pitiriasis versicolor por Malassezia pachydermatis: caso clínico / Pityriasis versicolor caused by Malassezia pachydermatis: clinical case

Se presenta un caso clínico de pitiriasis versicolor por M. pachydermatis en una paciente de 11 años de edad, diagnosticado mediante clínica, morfofisiología y biología molecular. Malassezia pachydermatis es parte de la microbiota común de diversos mamíferos domésticos y animales salvajes. En éstos se reconoce como agente causal de dermatitis y otitis externa. En humanos se han descrito escasas infecciones ya sea superficiales como invasoras, lo que puede atribuirse a la difícil transmisión y adaptación a partir de los animales domésticos. Se comentan los aspectos biológicos y epidemiológicos de esta infección zoonótica.

A clinical case of pityriasis versicolor caused by M. pachydermatis in an 11 year old patient which was diagnosed by means of clinic, morphophysiology and molecular biology is presented. Malassezia pachydermatis is part of regular microbiota in several domestic mammals as well as wild animals. It is recognized as the causing agent of dermatitis and external otitis in the latter. As to human beings, superficial infections have rarely been given an invasive character what can be explained by the difficult transmission and adaptation coming from domestic animals. Biological and epidemiological aspects of this zoonotic infection are described.

Pitiríase versicolor circinada: isolamento de Malassezia sympodialis: relato de caso / Pityriasis versicolor circinata: isolation of Malassezia sympodialis: case report

Os autores descrevem caso de pitiríase versicolor circinada, cujo agente etiológico isolado foi Malassezia sympodialis em uma mulher de 34 anos. O isolamento e identificação da Malassezia sympodialis foi em ágar Dixon modificado e o método molecular para confirmação da espécie foi PCR-RFLP (polymerase chain reaction and restriction fragment length polymorphism analysis).

The authors report a case of pityriasis versicolor circinata whose isolated etiologic agent was Malassezia sympodialis in a 34-year-old woman. The isolation and identification of Malassezia sympodialis were accomplished with modified Dixon's agar, and the molecular method used to confirm the species was polymerase chain reaction and restriction fragment length polymorphism analysis (PCR-RFLP).

Pitiríase versicolor: isolamento e identificação das principais espécies de Malassezia / Pityriasis versicolor: isolation and identification of the main species

As espécies do gênero Malassezia isoladas foram: Malassezia sympodialis (16,66 por cento), Malassezia furfur (12,50 por cento), Malassezia globosa (11,45 por cento) e Malassezia slooffiae (2,10 por cento). A Malassezia sympodialis foi a espécie que predominou em nosso estudo. As espécies de Malassezia identificadas não mostraram correlação com as variantes clínicas e com a distribuição das lesões de pitiríase versicolor quanto às regiões do corpo.

Species of the genus Malassezia isolated were: Malassezia sympodialis (16.66 percent), Malassezia furfur (12.50 percent), Malassezia globosa (11.45 percent), and Malassezia slooffiae (2.10 percent). Malassezia sympodialis predominated in the study. The species of Malassezia identified did not show correlation with clinical variants and with the distribution of pityriasis versicolor lesions in relation to areas of the body.

Skin diseases associated with Malassezia species in humans. Clinical features and diagnostic criteria.

Malassezia yeasts not only cause the well known pityriasis versicolor and folliculitis, but also play an important role in other skin diseases, including seborrheic dermatitis and atopic dermatitis. The presence of Malassezia yeasts may be confirmed by direct microscopic examination and cultures of skin scrapings. In pityriasis versicolor the direct microscopic examination is the rapidest and surest test for confirming the clinical diagnosis. The preparation will show a cluster of globose budding spores with thick or double wall and short hyphae. For detecting Malassezia in the other diseases the cultures is preferable. Culture is useful both for confirming the clinical diagnosis and for epidemiological investigations. The identification of the Malassezia species is not easy. The microscopic observation of the colony direct towards the identification of Malassezia species, but it is not enough to identify the colonies definitely. Several biochemical tests are necessary for a precise identification, such as catalase reaction, growth on media without lipid sources, ability to utilize hydrophilic emulsifiers as sole lipid source, esculin test, tryptophan test.

[Effects of Malassezia isolates on cytokines production associated with melanogenesis by keratinocytes].

OBJECTIVE: To investigate the co-culture of keratinocytes with Malassezia isolates which cause the pityriasis versicolor with different color and to analyze the changes of cytokines associated with melanogenesis. METHODS: The effects of Malassezia species with different proportions on the growth rate of keratinocytes was assessed with 5 g/L methyl thiazolyl tetrazolium (MTT). Co-culture of keratinocytes and Malassezia species were performed with isolates from hyer- and hypo-pigmentation areas of pityriasis versicolor. The supernatants were collected at different time points, and the changes of basic fibroblast growth factor (b-FGF), endothelin-1 (ET-1), nerve growth factor-beta (NGF-beta), interleukin-1alpha (IL-1alpha), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), stem cell factor (SCF) were recorded. Three control groups were established accordingly. RESULTS: When the ratio between keratinocytes and Malassezia species was lower than 1: 10, the growth rate of keratinocytes was not affected by Malassezia (P > 0.05). When the ratio was increased above 1:20, the growth rate of keratinocytes was significantly inhibited by Malassezia (P < 0.01). The secretions of IL-1alpha, IL-6, TNF-alpha, and ET-1 was significantly increased after the co-culture of keratinocytes and Malassezia (P < 0.01), while those of b-FGF, NGF-beta, and SCF had no significant changes (P > 0.05). Compared with the isolates from the hypo-pigmentation area, ET-1 induced by isolate from hyperpigmentation area significantly increased (P < 0.01). CONCLUSION: When Malassezia isolates are co-cultured with keratinocytes, the secretions of cytokines associated with melanogenesis may differ from each other. ET-1 may play certain role in the hyper-pigmentation of pityriasis versicolor.

Identificação de espécies de Malassezia em pacientes com pitiríase versicolor em Goiânia-GO / Identification of Malassezia species in patients with pityriasis versicolor in Goiânia-GO

O objetivo deste estudo foi verificar a freqüência de pitiríase versicolor e identificar leveduras do gênero Malassezia, de pacientes encaminhados ao laboratório de Micologia da Universidade Federal de Goiás em Goiânia. Foram diagnosticados 95 casos de pitíriase versicolor e identificados quatro espécies de Malassezia: Malassezia furfur, Malassezia sympodialis, Malassezia globosa e Malassezia obtusa.

The objectives of this study were to investigate the frequency of pityriasis versicolor occurrence and to identify yeasts of the genus Malassezia in patients at the mycology laboratory of the Federal University of Goiás, in Goiânia, State of Goiás. Ninety-five cases of pityriasis versicolor were diagnosed, and four species of Malassezia were identified: Malassezia furfur, Malassezia sympodialis, Malassezia globosa and Malassezia obtusa.

Genotyping by RAPD-PCR analyses of Malassezia furfur strains from pityriasis versicolor and seborrhoeic dermatitis patients.

Malassezia furfur is lypophilic yeast commonly associate with dermatological disorders. In the present work, we described the isolation of 47 M. furfur strains from three groups of patients: pityriasis versicolor (21 isolates), seborrhoeic dermatitis (15 isolates) and seborrhoeic dermatitis of the HIV positive patients (11 isolates). To investigate the identity of the strains at molecular level, DNA genomic of M. furfur strains were prepared and used to RAPD-PCR analyses. RAPD assay were carried out using two decamer primers and bands pattern generated were analyzed by an Unweighted Pair-Group Method (UPGMA). Dendrogram established a distinct differentiation between M. furfur isolates from pityriasis versicolor and seborrhoeic dermatitis patients with or without AIDS. We concluded that RAPD typing presented a high discriminatory power between strains studied in this work and can be applied in epidemiological investigation of skin disease causing by M. furfur.

Hyperkeratotic head and neck Malassezia dermatosis.

BACKGROUND: Pityriasis versicolor (tinea versicolor) is a common skin disorder due to Malassezia usually affecting adolescents and young adults, more frequently in the tropics. Facial involvement, isolated or not, is not frequent in white adults. OBJECTIVE: Here, we report a possible atypical hyperkeratotic form of dermatosis of the face, in two young immunocompetent Caucasian patients, particularly recalcitrant to therapy. RESULTS: Skin scrapings grew yeasts belonging to the genus Malassezia, including both M. globosa and M. sympodialis. This unusual variant needs long-term therapy with systemic and topical imidazoles together with facial cleansing. CONCLUSION: We propose the name hyperkeratotic head and neck Malassezia dermatosis for this distinctive clinical entity. This variant of pityriasis versicolor should be considered in the differential diagnosis of seborrheic dermatitis and dermatitis neglecta.

Skin diseases associated with Malassezia species.

The yeasts of the genus Malassezia have been associated with a number of diseases affecting the human skin, such as pityriasis versicolor, Malassezia (Pityrosporum) folliculitis, seborrheic dermatitis and dandruff, atopic dermatitis, psoriasis, and--less commonly--with other dermatologic disorders such as confluent and reticulated papillomatosis, onychomycosis, and transient acantholytic dermatosis. Although Malassezia yeasts are a part of the normal microflora, under certain conditions they can cause superficial skin infection. The study of the clinical role of Malassezia species has been surrounded by controversy because of their fastidious nature in vitro, and relative difficulty in isolation, cultivation, and identification. Many studies have been published in the past few years after the taxonomic revision carried out in 1996 in which 7 species were recognized. Two new species have been recently described, one of which has been isolated from patients with atopic dermatitis. This review focuses on the clinical, mycologic, and immunologic aspects of the various skin diseases associated with Malassezia. It also highlights the importance of individual Malassezia species in the different dermatologic disorders related to these yeasts.

Superficial fungal infections.

Superficial fungal infections arise from a pathogen that is restricted to the stratum corneum, with little or no tissue reaction. In this Seminar, three types of infection will be covered: tinea versicolor, piedra, and tinea nigra. Tinea versicolor is common worldwide and is caused by Malassezia spp, which are human saprophytes that sometimes switch from yeast to pathogenic mycelial form. Malassezia furfur, Malassezia globosa, and Malassezia sympodialis are most closely linked to tinea versicolor. White and black piedra are both common in tropical regions of the world; white piedra is also endemic in temperate climates. Black piedra is caused by Piedraia hortae; white piedra is due to pathogenic species of the Trichosporon genus. Tinea nigra is also common in tropical areas and has been confused with melanoma.

Atrophying tinea versicolor: a clinical and histological study of 12 patients.

BACKGROUND: We describe 12 patients with an atrophying dermatitis in whom the biopsy findings were compatible with tinea versicolor. DESIGN: We encountered 12 skin biopsies from 12 patients in whom a clinically atrophying dermatosis was associated with light microscopic (LM) evidence of atrophy and epidermal colonization by Pityrosporum sp. Formalin-fixed, paraffin-embedded tissue sections were cut at 5 microns and stained with H&E, alcian blue-PAS and PAS-diastase preparations. RESULTS: Five men and seven women aged 17-73 years in whom lesions characterized as atrophic plaques, patches or macules prompted clinical differential diagnoses including parapsoriasis or mycosis fungoides (MF), anetoderma, lupus erythematosus, and steroid atrophy. A LM examination showed epidermal colonization with pityrosporum hyphae and spores accompanied by variable epidermal and dermal atrophy characterized by rete-ridge effacement, subepidermal fibroplasia, pigment incontinence and elastolysis. CONCLUSIONS: Atrophying cutaneous lesions comprise part of the clinical spectrum of tinea versicolor for which we propose the term 'atrophying tinea versicolor'. The pathogenetic basis is unclear but could be the sequela of delayed type hypersensitivity and the release by T-helper lymphocytes of leukotrienes which perturb collagen metabolism and/or keratinocyte growth. Lesions may be mistaken clinically for MF or other atrophying dermatoses.