Atrophying pityriasis versicolor as an idiosyncratic T cell-mediated response to Malassezia: A case series.

BACKGROUND: Atrophying pityriasis versicolor (PV), first described in 1971, is a rare variant in which lesions appear atrophic. OBJECTIVE: We sought to determine the pathophysiology of atrophying PV. METHODS: A retrospective chart review identified 6 cases of atrophying PV. In all cases, routine light microscopy, an elastic tissue stain, and immunohistochemical assessment for the expression of CD3, CD4, CD8, GATA3 and CXCR3 was performed. RESULTS: All cases demonstrated hyperkeratosis with intracorneal infiltration by pathogenic hyphal forms as well as epidermal attenuation and papillary dermal elastolysis. A supervening, mild-to-moderate, superficial lymphocytic infiltrate was noted and characterized by a focal CD8+ T cell-mediated interface dermatitis along with a mixed T-cell infiltrate composed of GATA3+ and CXCR3+ T cells. LIMITATIONS: Small sample size and the loss of some patients to follow-up. CONCLUSION: Atrophying PV represents the sequelae of a mixed helper T-cell (TH1 and TH2) idiosyncratic immune response to Malassezia and can present as a protracted dermatosis that may clinically mimic an atypical lymphocytic infiltrate. TH1 cytokines can recruit histiocytes, a source of elastases, and upregulate matrix metalloproteinase activity, which may contribute to epidermal atrophy.

Pitiriasis versicolor simulando tricostasis espinulosa / Pityriasis versicolor mimicking trichostasis spinulosa

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Identification of Malassezia species isolated from patients with extensive forms of pityriasis versicolor in Siena, Italy

Background. Pityriasis versicolor (PV) is an infection caused by various species of Malassezia yeast. There is no agreement in the literature concerning the species of Malassezia and the demographic, clinical, and mycological data. Aims. To prospectively identify Malassezia species isolated from lesions of patients with extensive, long standing and recurrent forms of PV and to estimate the relationship between Malassezia species and the demographic and clinical data of the patients. Methods. All patients with PV were enrolled over a four-year period. Malassezia species were isolated in cultures and identified by morphological features and physiological tests. In the last 2 years a PCR-based technique was used to confirm the species’ identification. Results. A total of 74 patients (43 males and 31 females, mean age 39.5 years) were enrolled. Only one species was isolated in 45 patients, and more than one species were identified in the remaining 28 patients (38%). M. globosa was the most frequently isolated (60.3%) species. There was a significant association between the isolation of 2 or more species and the presence of at least one predisposing factor. In the last 29 cases, which were subjected to PCR, there were no differences in the identification of isolated species as compared to traditional methods. Conclusions. The isolation of more than one species in a single lesion is not infrequent in PV and is related to the presence of one predisposing factor. The isolated species isolated were not influenced by demographic and clinical features. The traditional and more recent (PCR) procedures gave the same results in the isolated species (AU)

Disruption of barrier function in dermatophytosis and pityriasis versicolor.

Dermatophytes have the ability to form molecular attachments to keratin and use it as a source of nutrients, colonizing keratinized tissues, including the stratum corneum of the skin. Malassezia species also affect the stratum corneum of the skin. Therefore, dermatophytosis and pityriasis versicolor of the skin are thought to be important factors of profound changes in skin barrier structure and function. We aimed to describe the changes in transepidermal water loss (TEWL), stratum corneum hydration, and skin pH in the lesions of the dermatophytosis and pityriasis versicolor. Thirty-six patients with dermatophytosis (14 with tinea cruris, 13 with tinea corporis and nine with tinea pedis or tinea manus) and 11 patients with pityriasis versicolor were included in this study. TEWL, stratum corneum conductance and skin pH were determined by biophysical methods to examine whether our patients exhibited changes in barrier function. Dermatophytosis and pityriasis versicolor except tinea pedis and tinea manus showed highly significant increase in TEWL compared with adjacent infection-free skin. Hydration was significantly reduced in lesional skin compared with adjacent infection-free skin. From this study, infections with dermatophytes and Malassezia species on the body can alter biophysical properties of the skin, especially the function of stratum corneum as a barrier to water loss. On the contrary, infections with dermatophytes on the palms and soles little affect the barrier function of the skin.

Quantification of ultraviolet protective effects of pityriacitrin in humans.

Pityriacitrin (PIT), produced by Malassezia yeasts, is an UV absorbing substance that might cause hypopigmentation in pityriasis versicolor alba. We aimed to investigate the UV protective effect of PIT in humans using in vitro and in vivo test methods. Spectrophotometry of PIT cream and the vehicle was performed in the wavelength range from 290 to 400 nm. UV transmission and the sun protection factor (SPF) were assessed for different cream formulations. Using colorimetry we evaluated erythema and pigmentation following irradiation of cream-protected and non-protected skin of healthy subjects. UVB as well as UVA transmission decreased with increasing PIT concentrations. An increase of PIT concentration of 1.25, 2.5, and 5% was associated with slightly increasing SPFs of 1.4, 1.5, and 1.7, respectively. Our in vivo tests confirmed the validity of the SPF of PIT 5% cream determined in vitro. In conclusion, the UV protective effect of PIT is all in all very weak suggesting that PIT is likely only an inferior cofactor in the development of hypopigmentation in pityriasis versicolor alba lesions following sun exposure.

Etiopatogenia y tratamiento de la pitiriasis versicolor / Etiology, pathogenesis and treatment of pityriasis versicolor

La pitiriasis versicolor es una infección fúngica superficial de la piel producida por hongos lipofílicos dimórficos pertenecientes al género Malassezia spp., que forman parte de la flora normal de la piel. De las especies descritas, las responsables más frecuentes de la clínica son M. globosa, M. sympodialis y M. furfur. En España, el agente patógeno más frecuente es M. globosa. Se presenta en forma de máculas redondas u ovales de pequeño a mediano tamaño y coloración, eritematosas, hiperpigmentadas o hipopigmentadas. Su superficie suele estar cubierta por una fina descamación. Son más frecuentes en las áreas de distribución de las glándulas sebáceas, sobre todo en el tercio superior del tronco, de forma especial en la espalda, la raíz de los miembros superiores, el cuello y con menor frecuencia en la cara. En su tratamiento se han utilizado diferentes agentes terapéuticos tópicos (ciclopiroxolamina, azoles, griseofulvina, terbinafina, succinato de litio) o sistémicos (ketoconazol, itraconazol, fluconazol) (AU)

Pityriasis versicolor is a superficial fungal infection of the skin produced by lipophilic dimorphic fungi belonging to the genus Malassezia spp, which form part of the normal skin flora. Of the species described, those most frequently producing symptoms are M. globosa, M. sympodialis and M. furfur. In Spain, the most frequent pathogenic agent is M. globosa. It most frequently presents as small or mediumsized circular or oval, erythematous, hyperpigmented or hypopigmented macules. The surface is usually covered by fine desquamation. The most frequently affected areas are those supplied by the sebaceous glands, mainly the upper third of the trunk, especially the shoulder, proximal upper extremities, the neck, and less frequently, the face. Various topical agents (ciclopirox olamine, azoles, griseofulvin, terbinafine, lithium succinate) and systemic agents (ketoconazole, itraconazole, fluconazole) have been used in the treatment of pityriasis versicolor (AU)

Revisión metodológica de los ensayos clínicos en micosis cutáneas superficiales / Methodological review of clinical trials in superficial cutaneous mycoses

En esta revisión se exponen aspectos generales de los ensayos clínicos, así como de las micosis cutáneas, para finalizar con el diseño de ensayos clínicos aplicado a dicha afección, con el objetivo de facilitar la interpretación crítica de los estudios publicados en la bibliografía. Se definen los ensayos clínicos, se describen los diferentes tipos y se incide en la definición de poblaciones y en las variables utilizadas como medida de la respuesta a un tratamiento experimental. Los ensayos clínicos en micosis pueden estar diseñados de formas diversas que condicionen las conclusiones finales y, por ello, es importante que el clínico disponga de los conocimientos que este artículo pretende aportar (AU)

This review presents general aspects concerning clinical trials and cutaneous mycoses, and ends with a discussion of the design of clinical trials applied to these infections, with the aim of facilitating critical interpretation of studies published in the literature. Clinical trials are defined, the distinct types are described and the definition of the populations and the variables used to measure response to an experimental treatment are stressed. Clinical trials in mycoses can have various designs that influence the final conclusions. Therefore, it is important for the clinician to be aware of the knowledge that this article aims to provide (AU)

[Missing granulocytic infiltrate in pityriasis versicolor--indication of specific anti-inflammatory activity of the pathogen?]. / Fehlendes granulozytäres Infiltrat bei der Pityriasis versicolor--ein Hinweis für eine spezifische antiinflammatorische Aktivität des Erregers?

The yeast Malassezia furfur is a part of the resident flora of human skin. It causes various diseases such as pityriasis versicolor, which hardly shows signs of inflammation despite marked clinical symptoms (e.g. hypopigmentation). The pathophysiology related morphological picture might give a clue to this phenomenon. As a part of the literature data are controversial, the present study compared the inflammatory infiltrate of pityriasis versicolor with that of tinea corporis in 40 human skin preparations each from diagnostic specimens. All preparations were stained with HE and PAS. Neutrophilic granulocytes were counted in the HE stain, and hyphae and spores in the PAS stain. The number of counted cells was related to the size of the respective area and the values were compared between pityriasis and tinea corporis. Significantly, more neutrophilic granulocytes were found with tinea corporis (P > 0.01), while they were virtually not demonstrable with pityriasis versicolor. It is surprising that fungal load in the stratum corneum is significantly higher with pityriasis versicolor (P > 0.01). Obviously the immune response involving neutrophilic granulocytes does not occur despite high bacterial load. This might be explained by reduced immunogenicity because of high content of lipids in the cell membrane. Furthermore, pityriarubins that are produced during tryptophan metabolism might be involved, which, in a stimulus-dependent manner, can suppress the ROS production of neutrophilic granulocytes in vivo.

The epidemiology of pityriasis versicolor in Malawi, Africa.

During a total population survey in 1988 and 1989 in Karonga district, northern Malawi, 4915/61735 (8.0%) people examined were found to have extensive pityriasis versicolor (PV). An additional 6085 people (9.9%) were diagnosed as having mild disease. The highest prevalence rates of extensive and mild PV were found among subjects aged 15-24 years. In this age group between 20% and 25% of people had extensive PV. Rates were generally higher among males than among females. PV was rarely found in prepubertal subjects.

The superficial mycoses.

The various agents of the superficial mycoses have been recognized for more than a century as causes of mild diseases affecting humankind. Two of these, Malassezia furfur and Trichosporon beigelii, are ubiquitous organisms now known to be opportunistic pathogens in susceptible patient populations. The clinical manifestation, pathogenesis, and treatment of the common skin presentation of these and the other superficial mycoses are reviewed.

Yeast infections.

Yeasts are unicellular fungi that reproduce by the process of budding in which daughter cells are produced from parents by outpouching of the cell membrane and wall, migration of cytoplasm into the new structure thus formed, and then separation from the parent cell. Yeasts that are pathogenic in humans range in size from 2 to 12 microns in diameter; most, therefore, can be engulfed by phagocytic cells. These pathogens include many of the best known of pathogenic fungi, such as the Candida species, Cryptococcus neoformans, and the lipophilic yeasts of the genus Malassezia.

[Study on cutaneous physio-immuno-pathological status in tinea versicolor].

This study examined 20 cases of tinea versicolor to assess the dermato-physiological, immunological and pathological status of lesion sites as compared to 20 normal control subjects. Lesion sites showed a significant decrease in sebaceous gland secretions and water content and an increase in pH value compared to normal skin. There was no significant change in involucrin, filaggrin, or number of stratum corneum cell layers. However, lesions showed weak positive staining of IL-1 alpha. A possible mechanism for these changes is that profuse sweat gland secretions predispose to fungal growth and acid mantle destruction, with the pathogens consuming amino acids and sebum as nutrients. Slight increases in IL-1 alpha levels seen in infected areas could be due to a fungus-stimulated immune reaction in the stratum corneum.

Itraconazol no tratamento da pitiríase versicolor: esquema de cinco dias / Itraconazole in the treatment of pityriasis versicolor: 5-day schedule

Foram tratados 30 pacientes com pitiríase versicolor na posologia de duas cápsulas de 100mg cada, uma vez ao dia, junto com o almoço por cinco dias. A diagnose foi clínica, comprovada por exame em luz de Wood e exame direto. Os doentes foram avaliados no décimo quinto e trigésimo dia após o término do tratamento pelos mesmos parâmetros iniciais. Os resultados após 30 dias mostraram cura clínica e micológica em 27(90%) dos doentes e falha em três (10%). A tolerabilidade foi excelente observando-se apenas dois casos de efeitos adversos de natureza leve, transitória, com desaparecimento espontâneo após término do tratamento