Pityriasis Versicolor Lesions Research Articles

Malasseziayeast species isolated from Iranian patients with pityriasis versicolor in a prospective study

The goal of this study was to determine the prevalence of Malassezia species in pityriasis versicolor lesions and to examine if the range of species varies with patients characteristics such as: age, sex and family history and also clinical findings such as site and number of the lesions. In a prospective study from July 2006 to July 2007, the patients with a clinical diagnosis of pityriasis versicolor (n = 166) were asked to participate in the study. A total of 116 patients had positive culture for Malassezia species: M. globosa was found in 52 (31.3%) cases, M. furfur in 34 (20.5%) cases, M. pachydermatis in 12 (7.2%) cases, M. restricta in 12 (7.2%) cases, M. slooffiae in 6 (3.6%) cases. According to our data, M. globosa is the main species causing pityriasis versicolor, M. furfur was found to be the second-most frequent species. M. sympodialis and M. obtusa were not found in any case, and in 30.2% of patient's Malassezia culture was negative.

La pitiriasis versicolor y las levaduras del género Malassezia

Although pityriasis versicolor is the only human disease for which Malassezia yeasts have been fully established as pathogens, it is still not clear which species are implicated. Most studies carried out in recent years support our hypothesis —proposed in 1999— that Malassezia globosa is the predominant species in pityriasis versicolor lesions, at least in temperate climates. Confirmation of this hypothesis could help us understand the conditions, as yet unclear, that induce transformation of this yeast from the saprophytic form present in healthy skin to the parasitic form, characterized by the formation of pseudomycelium, and could also guide therapy. In addition, isolation of another species, Malassezia furfur, which seems to be predominant in the tropics, raises the possibility of a second etiologic agent confined to certain areas, as occurs with some other human mycoses.

Pityriasis Versicolor and the Yeasts of Genus Malassezia

Although pityriasis versicolor is the only human disease for which Malassezia yeasts have been fully established as pathogens, it is still not clear which species are implicated. Most studies carried out in recent years support our hypothesis —proposed in 1999— that Malassezia globosa is the predominant species in pityriasis versicolor lesions, at least in temperate climates. Confirmation of this hypothesis could help us understand the conditions, as yet unclear, that induce transformation of this yeast from the saprophytic form present in healthy skin to the parasitic form, characterized by the formation of pseudomycelium, and could also guide therapy. In addition, isolation of another species, Malassezia furfur, which seems to be predominant in the tropics, raises the possibility of a second etiologic agent confined to certain areas, as occurs with some other human mycoses.

Comparison between fluconazole and ketoconazole effectivity in the treatment of pityriasis versicolor

Topical drugs are often effective in limited lesions of pityriasis versicolor; but in extensive cases, systemic drugs are more suitable. Previous studies have shown that ketoconazole and fluconazole are effective in 42-97% and 74-100% of lesions respectively. Our purpose was to compare the effectiveness of a single dose of 400 mg ketoconazole with two doses of 300 mg of fluconazole with 2 weeks interval. Ninety patients with extensive pityriasis versicolor (body involved area > or =25%) were randomly assigned to treatment with either a single dose of 400 mg of ketoconazole or with two doses of 300 mg of fluconazole with 2 weeks interval. One month after the treatment, the improvement rate and side effects were evaluated by clinical examination and questionnaire. Sixty cases (66.7%) completed the study. They were 51 males and nine females, with a mean age of 30 years. At the follow-up visit (1 month after the end of treatment), the improvement rate for ketoconazole (87.9%) was not significantly different from fluconazole (81.5%), (Fisher test: P = 0.37). Due to the hepatotoxicity of ketoconazole, fluconazole appears to be more suitable in the treatment of extensive pityriasis versicolor.

Malassezia species isolated from lesional and non‐lesional skin in patients with pityriasis versicolor

Pityriasis versicolor (PV) is a superficial fungal infection where Malassezia species play a definite causative role, but the clinical significance of each of these species is not fully understood. The aim of our study was to analyse the prevalence of Malassezia species in PV lesions and to examine if the range of species varies with patient sex, age, direct microscopy findings and some clinical data. Ninety patients with PV completed the study. The samples were obtained by scraping the skin surface, both from lesional and non-lesional skin and then incubated on Sabouraud dextrose agar and modified Dixon agar. The yeast isolated were identified according to their macroscopic and microscoipic features and physiological characteristics. In PV lesions, the most common species was M. globosa (63%), followed by M. sympodialis (14%), M. furfur (10%), M. obtusa (8%) and M. slooffiae (4%). The most frequently isolated species from clinically healthy skin were M. globosa (49%), M. sympodialis (37%) and M. furfur (5%). We found significant difference in the distribution of Malassezia species between lesional and non-lesional skin and in the distribution of Malassezia species according to the direct microscopy findings. M. globosa in its mycelial phase is the predominant species involved in the aetiology of PV.

Malassezia yeasts and pityriasis versicolor

To analyze the relationships among different Malassezia species and pityriasis versicolor, the only human disease in which the etiologic role of these fungi is fully accepted (although the species implicated remains a matter of discussion). Since 1996, after the taxonomic revision of the genus, a limited number of papers analyzing the role of the different Malassezia species in pityriasis versicolor have been published or were the subject of presentations in congresses; there were only four in the past year. This paper discusses the results of these works, comparing them with results of the authors' most recent study in this field, conducted over the past 16 months. Most of the studies published thus far now show that Malassezia globosa is the predominant species found in the lesions of pityriasis versicolor, at least in temperate climates. The authors' recent findings confirm these results. The etiologic role of M. globosa in pityriasis versicolor is based, even more than on its isolation in a high percentage of cultures, on its identification by direct microscopy as typical globose yeast cells producing pseudohyphae in almost 100% of cases. The confirmation of the pathogenic role of this species in pityriasis versicolor could help in understanding these conditions, which are still unclear, which promote its transformation from the saprophytic stage present in healthy skin to the parasitic one, and could also help in selecting the best therapeutic measures.

Ausencia de lesiones del pliegue axilar en la pitiriasis versicolor

Increased temperature and sweating are considered factors predisposing to pityriasis versicolor. In this case report, sparing of the vaults of the axillae which are naturally occluded and sweaty areas, in a patient with widespread lesions of pityriasis versicolor is discussed. It is the second observation in this regard and further contributions are invited.

Identification of Malassezia species from Tunisian patients with pityriasis versicolor and normal subjects

The genus Malassezia (Pityrosporum), recognized as a member of microbiological flora of the skin in humans and warm-blooded animals, has been recently revised to include 10 Malassezia species. The aim of the study was the isolation, identification and analysis of Malassezia species distribution in skin of healthy volunteers and lesions of pityriasis versicolor (PV). Specimens were taken from 100 patients with PV and 30 healthy volunteers. Cultures were made in modified Dixon agar medium and the isolates were identified by morphological and physiological methods: macroscopy, microscopy, catalase, beta-glucosidase and lipid assimilation tests. Malassezia globosa was the predominant species in lesional skin of PV (65%). It was isolated alone in 47% of cases and associated in 18% with M. furfur (13%) or M. sympodialis (5%). In healthy skin M. globosa was found alone in 7.77% and associated in 15.54%, respectively, with M. furfur (4.44%), M. sympodialis (4.44%), M. restricta (3.33%) and M. slooffiae (1.11%). From these findings it was suggested that M. globosa presents the main species implicated in the pathogenicity of PV and M. furfur as the second agent of importance.

Study of the distribution of Malassezia species in patients with pityriasis versicolor and healthy individuals in Tehran, Iran.

BackgroundPityriasis versicolor is a superficial infection of the stratum corneum which caused by a group of yeasts formerly named pityrosporium. The taxonomy of these lipophilic yeasts has recently been modified and includes seven species referred as Malassezia. The aim of this study is to compare the distribution of Malassezia species isolated from pityriasis versicolor lesions and those isolated from healthy skins.MethodsDifferentiation of all malassezia species performed using morphological features and physiological test including catalase reaction, Tween assimilation test and splitting of esculin.ResultsIn pityriasis versicolor lesions, the most frequently isolated species was M. globosa (53.3%), followed by M. furfur (25.3%), M. sympodialis(9.3%), M. obtusa (8.1%) and M. slooffiae (4.0%). The most frequently isolated species in the skin of healthy individuals were M. globosa, M. sympodialis, M. furfur, M. sloofiae and M. restricta which respectively made up 41.7%, 25.0%, 23.3%, 6.7% and 3.3% of the isolated species.ConclusionsAccording to our data, M. globosa was the most prevalent species in the skin of healthy individuals which recovered only in the yeast form. However, the Mycelial form of M. globosa was isolated as the dominant species from pityriasis versicolor lesions. Therefore, the role of predisposing factors in the conversion of this yeast to mycelium and its subsequent involvement in pityriasis versicolor pathogenicity should be considered.

Intertriginous lesions in pityriasis versicolor.

The well-recognized sites of involvement in pityriasis versicolor are the upper part of the trunk, the neck and the upper arms. There is little documentation regarding pityriasis versicolor lesions in flexural areas. To study the occurrence and morphology of lesions of pityriasis versicolor in flexural areas. One hundred and ten cases of pityriasis versicolor were studied. Sites of lesions and other clinical features were determined. Flexural lesions in pityriasis versicolor were not uncommon. They were not correlated to age, sex, duration or relapses of the infection. Thorough inspection and examination of the skin by Wood's light before establishing treatment is prudent in cases of pityriasis versicolor located in typical sites.

Pityrialactone- a new fluorochrome from the tryptophan metabolism of Malassezia furfur.

As the main nitrogen source in Malassezia (M.) furfur, tryptophan induces the formation of fluorochromes and pigments, which makes the yeast less sensitive towards UV light. For the investigation of the fluorochromes, M. furfur (CBS1878) was incubated at 32 degrees C for 14 days on a pigment-inducing medium, and the agar extract was purified by column chromatography, preparative TLC and HPLC. The structures of the pure metabolites were determined by mass spectrometry and NMR spectroscopy. A pale yellow compound eluting from the column with 22% acetonitrile was found to exhibit a strong green-yellow fluorescence. The fluorochrome is a new bisindolyl compound (C(20)H(12)N(2)O(3), MW 328.33) named pityrialactone because of its furan-2,3-dione structure. The UV protective properties (lambda(max) 352, 292, 276, 224 nm) of this metabolite were confirmed in a yeast model. As shown by the fluorescence spectrum, pityrialactone appears to be responsible for the green-yellow fluorescence of pityriasis versicolor lesions under Wood light. Pityrialactone is accompanied by the isomeric bisindolylmaleic anhydride (pityriaanhydride), which has not yet been described as a natural product but is a known intermediate in the total synthesis of bisindolylmaleimides.

Isolation of Malassezia globosa and M. sympodialis from patients with pityriasis versicolor in Spain.

Pityriasis versicolor is a superficial infection of the stratum corneum by several yeast species formerly collectively named Malasseziafurfur. The genus Malassezia has been recently enlarged with new species. With the exception of M. pachydermatis, the remaining six species have an absolute requirement in vitro for supplementation of long-chain fatty acids in media. These lipophilic yeasts comprise six species: M. furfur, M. globosa, M. obtusa, M. restricta, M. slooffiae and M. sympodialis. The aim of this study was to establish whether there was any association between the various species of Malassezia and pityriasis versicolor lesions. Thus, we studied the isolates from 79 patients with pityriasis versicolor, both from lesions and from apparently healthy skin close to the visible lesions. In pityriasis versicolor lesions, the species most frequently isolated was M. globosa (90%), followed by M. sympodialis (41%). Almost all isolates (99%) belonged to one of these two species. The most frequent pattern was M. globosa as the sole species (58% of cases), although the association with M. sympodialis was also frequent (30%). These results confirmed M. globosa as the main agent of pityriasis versicolor and M. sympodialis as the second agent in importance. Malassezia globosa was found to be a species with high levels of esterase and lipase enzymes of probable importance in their pathogenicity.

Identification of causative species in malassezia-associated dermatoses

The Tween test was used to identify Malassezia species isolated from patients with pityriasis versicolor and seborrhoeic dermatitis, and suckling infants with seborrhoeic dermatitis. The most common species isolated from cases of pityriasis versicolor was M. globosa (55%), and this species was surmised to be the principal causative organism of this disease. In both adult and suckling infant cases of seborrhoeic dermatitis, M. globosa and M. furfur were isolated at high incidences compared with the healthy control subjects, indicating the possibility that one or both of these species are the causative organisms of these diseases. In addition, scales were collected from lesions of pityriasis versicolor for use as the template, and the involved Malassezia species were identified by the PCR method using the DNA sequences of nuclear ribosomal internal transcribed spacer l. The most commonly detected species was M. globosa, found in 97% of the cases, and this was followed in frequency by M. restricta (79%) and M. sympodialis (68%). It was also elucidated that multiple Malassezia species can be detected in the same specimen.

Malassezia globosa as the causative agent of pityriasis versicolor.

The taxonomic revision carried out in 1996 on the genus Malassezia, which now comprises seven different species, made necessary a re-evaluation of the data concerning the ecology and pathogenicity of these lipophilic yeasts. Very little has been published since then. The aim of this work was to contribute to the knowledge of the aetiology of pityriasis versicolor (PV) with a mycological study made according to the new species. Ninety-six patients with PV completed the study. In all of them, samples were taken from the lesions for direct microscopy with KOH+ Parker ink and culture. Samples were also taken from normal skin of the trunk and the forehead of the same patients for culture. Cultures were made in modified Dixon medium in Petri dishes, incubated at 31 degrees C and the isolates were identified by morphological and physiological characteristics. In the PV lesions, direct microscopy always showed the typical mixture of globose blastoconidia and pseudomycelium. Only one patient, having received previous topical antimycotic treatment, was negative. The spherical yeasts observed in vivo were morphologically identical to the globose yeasts characteristic of M. globosa. In culture, M. globosa was found in 97% of cases, alone in 60% of them and associated with M. sympodialis in 29% and M. slooffiae in 7%. These two species were also found in similar percentages on the clinically uninvolved skin of the trunk, whereas M. globosa was not isolated at these sites. However, on the forehead, a small number of colonies of M. globosa was recovered in 12% of cases. These results support the data previously reported and strongly suggest that M. globosa in its mycelial phase is the causative agent of PV.

Antifungal activity of ketoconazole and other azoles against Malassezia furfur in vitro and in vivo.

The in vitro activity of several antifungal agents (ketoconazole, miconazole, econazole, fenticonazole, itraconazole, fluconazole) in routine clinical use against Malassezia furfur infections has been studied with freshly isolated strains of M. furfur from pityriasis versicolor lesions. The results indicate that the drugs tested exert a good activity, and both ketoconazole and itraconazole appear very active (0.8 mg/l respectively). Hair samples from the beards of volunteer patients affected by pityriasis versicolor but otherwise healthy were examined to determine ketoconazole levels during oral therapy (one or two 200 mg tablets daily). It was shown that the drug progressively accumulates in the beard, reaching levels proportional to the dose administered, although blood levels did not increase in parallel. The study of drug concentration profile has evidenced a long ketoconazole persistence in the beard at therapeutic levels. In conclusion, the possibility of reaching high and lasting ketoconazole levels in the keratin layer of the epidermis indicates that systemic ketoconazole therapy could be useful for eradication of M. furfur in patients affected by pityriasis versicolor.

Two years of follow-up of oral ketoconazole therapy in 60 cases of pityriasis versicolor.

In a series of 60 patients (42 males, 18 females) with widespread lesions of pityriasis versicolor, 200 mg of oral ketoconazole was administered daily for a period of 24 days. Routine laboratory examinations, including microscopic and Wood's light examinations, were performed prior to initiation of treatment and twice during the treatment period as well as 3 and 6 months, and 1 and 2 years after completion of treatment. In 95% of the patients the clinical cure was maintained after 3 months but after 6 months it was still present in only 80% and after one year in only 57%. At the end of two years 60% showed relapse of the disorder. In 75% hypopigmented macules persisted after 6 months but without microscopic evidence of the fungus. No side effects were reported. It is evident that oral ketoconazole is effective in maintaining a clinical cure mainly during the first 3 months after treatment. The question as to whether side effects might appear with a more prolonged course of the drug should be given serious consideration before continuation of treatment is contemplated.