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Introduction: Malassezia spp. are a group of lipid-dependent basidiomycetes yeasts acting as commensal organisms of the human and animal skin. However, under some not well-defined circumstances, these yeasts may switch to opportunistic pathogens triggering a number of skin disorders with different clinical presentations. The genus comprises of 18 lipid-dependent species with a variable distribution in the hosts and pathologies thus suggesting a host- and microbe-specific interactions., Area Covered: This review highlighted and discussed the most recent literature regarding the genus Malassezia as a commensal or pathogenic organisms highlighting Malassezi a-associated skin disorders in humans and animals and their antifungal susceptibility profile. A literature search of Malassezia associated skin disorders was performed via PubMed and Google scholar (up to May 2023), using the different keywords mainly associated with Malassezia skin disorders and Malassezia antifungal resistance., Expert Opinion: Malassezia yeasts are part of the skin mycobiota and their life cycle is strictly associated with the environment in which they live. The biochemical, physiological, or immunological condition of the host skin selects Malassezia spp. or genotypes able to survive in a specific environment by changing their metabolisms, thus producing virulence factors or metabolites which can cause skin disorders with different clinical presentations.

Dihydroxyacid dehydratase (DHAD) is a key enzyme in biosynthetic pathway of isoleucine and valine. This pathway is absent in human but exists in various organisms such as fungi. Using RNA-seq analysis in this study, we identified MGL_3741gene which encodes DHAD protein in Malassezia globosa (M. globosa). Furthermore, we found that mentioned gene is homologous to the Ustilago maydis, Saccharomyces cerevisiae, Aspergillus flavus, and Aspergillus fumigatus ILV3P. For understanding the probable role of this gene in pathogenicity of M. globosa, we applied Real-time PCR to investigate the differentially expressed of the MGL_3741 gene in healthy and pathogenic states. Our results indicate a significant difference between two mentioned stats. These results revealed that ILV3-like gene in M. globosa can be related to the pathogenicity of this yeast., (© 2018 Blackwell Verlag GmbH.)

Pityriasis versicolor (PV) is a superficial mycosis caused by yeast of the genus Malassezia. The most common isolated Malassezia species in PV lesions differ among M. furfur, M. globosa and M. sympodialis. We purpose to determine the distribution of Malassezia species in PV patients at the seafarers' medical service in Dakar, Senegal and to examine whether any association between identified Malassezia species and patients' profile. From May 2017 to August 2017, first a questionnaire was filled to get informative data before collection of skin scrapings taken from most scaly site using sterile scalpel blade and application of scotch ® for direct examination (DE). At the laboratory, DE, culture and identification by MALDI-TOF MS were done. One hundred patients with PV - all men - were included with a mean age of 34 years. Among seafarers, 81% were sailors. Clinical prevalence of PV was highest in aged adults patients with ages of 31 to 60 years (56%). Seafarers with high level of education were less representative with only 2%. The mean duration of the PV was 26.83 months. 20% of subjects suffered lesions in more than one location. The chest was the most affected anatomical site. Furthermore, possible predisposing factors associated with PV were also detected. DE was positive in 95% but culture growth only in 46%. MALDI-TOF MS analysis of the positive cultures could be performed in 84.8% (39/46). Only M. furfur was identified in 100% (39/39). In definitive, M. furfur is the only causative agent of PV in Dakar., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

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 (T H 1 and T H 2) idiosyncratic immune response to Malassezia and can present as a protracted dermatosis that may clinically mimic an atypical lymphocytic infiltrate. T H 1 cytokines can recruit histiocytes, a source of elastases, and upregulate matrix metalloproteinase activity, which may contribute to epidermal atrophy., (Copyright © 2016. Published by Elsevier Inc.)

Tinea versicolor (TV) is typically an asymptomatic fungal infection of the stratum corneum owing to Malassezia overgrowth. It presents as hypo or hyperpigmented macules with fine scale that coalesce into patches on the trunk, neck, and/or arms. Presented in this report is a 34-year-old man with an interesting case of folliculocentric tinea versicolor manifesting as perifollicular hypopigmented macules on the lower back.

We report two cases of Pityriasis versicolor (PV) in infants aged 12 and 18 months. The latter were brought to medical attention because of hypochromic and achromic, round macules involving the limbs and the face. Physical examination of their mothers showed voluntary depigmentation for cosmetic purposes due to the use of corticosteroids and hydroquinone, on average, over a 5-year period. The scotch tape test performed in one of the infants and his mother showed short filaments and clusters of spores. Treatment was based on ketoconazole. After 8 weeks, all patients reported favorable outcomes despite the persistence of some hypochomic macules. The peculiarities of this study are, on the one hand the topography of the lower limbs and on the other hand a positive family history of PV whose occurrence is favored by the use of depigmenting agents based on corticosteroids. Corticosteroids favor the atrophic and achromic feature of the lesions. Indeed, achromic lesions on the lower limbs were described in adults undergoing artificial depigmentation., Competing Interests: Les auteurs ne déclarent aucun conflit d’intérêts.

Background: Geographical variation in the distribution of Malassezia species associated with pityriasis versicolor (PV) has led to the necessity of studying epidemiological, mycological, and clinical characteristics of PV., Aims: To study the epidemiological, mycological, and clinical characteristics of PV in a tertiary care hospital., Settings and Design: The study was carried out with a cross-sectional design., Materials and Methods: Two hundred and sixty-two consecutive PV patients were subjected to detailed history, clinical examination, and investigations. Skin scrapings were processed by direct microscopy and culture. Isolates were identified by phenotypic characteristics and polymerase chain reaction-restriction fragment length polymorphism. Association of Malassezia species with clinical and epidemiological characteristics was studied. Statistical analysis of the data was done using statistical software., Results: Maximum number of PV cases (33.9%) belonged to the age group of 21-30 years with a male preponderance. 61.4% of the patients had a sedentary lifestyle, 70.2% showed the gradual onset of the disease, 51.1% presented with pruritus and in 66.4% of the patients symptoms were continuous. Most commonly involved body site was neck (27.8%), 77.09% of the lesions were bilaterally asymmetrical, 87.4% were macular, and 89.3% were hypopigmented. Malassezia furfur (77.3%) was the predominant species. Sedentary lifestyle (61.4%) and increased sweating (48%) were the most commonly associated predisposing factors., Conclusion: PV is more common in males. Distribution of Malassezia species varies significantly from those reported in other parts of India. M. furfur was the most common species responsible for PV in our region. Hence, further studies are required to evaluate the exact cause of this variation.

Malassezia spp. are lipophilic fungi that occur on all skin surfaces of humans and animals as commensal and pathogenic organisms. In the 2000s, several new species were added to the Malassezia genus by Japanese researchers. The genus Malassezia now includes 14 species of basidiomycetous yeast. Culture-independent molecular analysis clearly demonstrated that the DNA of Malassezia spp. was predominantly detected in core body and arm sites, suggesting that they are the dominant fungal flora of the human body. Malassezia spp. have been implicated in skin diseases including pityriasis versicolor (PV), Malassezia folliculitis (MF), seborrheic dermatitis (SD) and atopic dermatitis (AD). While Malassezia spp. are directly responsible for the infectious diseases, PV and MF, they act as an exacerbating factor in AD and SD. The fatty acids generated by Malassezia lipase can induce inflammation of the skin, resulting in development of SD. Patch and serum immunoglobulin E tests revealed that AD patients were hypersensitive to Malassezia. However, these findings only partially elucidated the mechanism by which Malassezia spp. induce inflammation in the skin; understanding of the pathogenetic role of Malassezia spp. in SD or AD remains incomplete. In this article, the latest findings of Malassezia research are reviewed with special attention to skin diseases., (© 2015 Japanese Dermatological Association.)

Objectives: The objective of this research was to evaluate the efficacy of a new antifungal imidazole, dapaconazole tosylate, in the treatment of Pityriasis versicolor (PV)., Design and Methods: Sixty patients with clinical and mycological diagnosis of PV were randomly assigned to receive either 1 g dapaconazole tosylate 2% cream or 1 g ketoconazole 2% cream. Treatments were applied once a day for 28 days. A dermatologist evaluated efficacy and safety daily, and weekly laboratorial tests were performed. The primary end point was a clinical and mycological cure of lesions after 28 days of treatment. The secondary end point was the time to clinical healing assessed by Kaplan-Meier analysis and Log-rank testing., Results: Fifty-three patients adhered to protocol rules. Clinical and mycological cure was achieved in 84.6% (22/26) and 92.6% (25/27) of patients treated with ketoconazole and dapaconazole, respectively (difference [effect size] = 8.0%, Standard error of difference: 8.69%, 95% CI: -6.3 to 22.3%). Median time to healing was 23.5 and 21 days for ketoconazole and dapaconazole, respectively (p = 0.126). Adverse events occurred only in ketoconazole-treated patients (13%; 4/30)., Conclusion: Dapaconazole tosylate is non-inferior to ketoconazole when used at a dose of 20 mg/day for 28 consecutive days for the treatment of PV. Dapaconazole also demonstrated a good safety profile.

Background: Pityriasis (tinea) versicolor is a superficial fungal infection of the stratum corneum caused by Malassezia species. The diagnosis is made clinically by its classic appearance of round or oval macules with fine scale that may be hyperpigmented or hypopigmented. Diagnosis may also be confirmed with microscopic evaluation of skin scrapings that reveal both short, stubby hyphae, and spores under KOH preparation. Ketoconazole is an important treatment of pityriasis versicolor but is primarily used in cream formulas. A foam vehicle has been shown to improve drug absorption through the stratum corneum and distribution in the skin. This study has assessed the safety and efficacy of ketoconazole 2% foam in treatment of pityriasis versicolor., Methods: Ketoconazole 2% foam was evaluated in a single-center, open-label, one-arm pilot study which enrolled eleven subjects to gain 10 evaluable subjects aged 21 years and older with a clinical diagnosis of tinea versicolor and positive KOH using calcofluor. The subjects came for 4 scheduled visits (baseline, week 1, week 2, and week 4) and were instructed to apply ketoconazole 2% foam to all affected areas twice daily for 2 weeks. At each visit, mycological and clinical assessment of a target area was done, along with static global assessment and body surface area estimation of the disease in each subject. Patient questionnaires were given at baseline and at week 2 to rate pruritus and satisfaction with the foam., Results: At the week 2 visit, following the treatment period, three out of ten evaluable subjects had negative skin samples prepared with KOH/calcifluor. Of these three, one subject later showed recurrence of fungal elements consistent with tinea versicolor at the week 4 follow-up visit. The other negative subjects remained negative and four additional subjects tested negative at week 4. Three subjects with positive samples at week 4 had only yeast forms without hyphae present. Investigator ratings of the target area were averaged for each clinical feature and demonstrated improvement in scale, hyper- or hypopigmentation, erythema, and induration throughout the study. Average pruritus score increased slightly 1 week after the baseline visit, but then improved steadily over the remaining visits. The investigator's static global assessment rating showed improvement from mild to moderate disease at baseline to minimal or no disease at week 4 in 7 subjects. The remaining subjects showed neither improvement nor progression of the disease throughout the study. One out of the eleven subjects enrolled did not complete the study. One subject noted mild skin burning sensation after application of medicine. Post-treatment patient questionnaires indicated overall satisfaction with the foam vehicle., Limitations: This was a single-arm, open-label, noncomparative trial., Conclusion: Ketoconazole 2% foam improved overall clinical assessment and microscopic evidence of pityriasis versicolor in all subjects with favorable patient feedback regarding the novel foam vehicle.

Objective: To report a case of isolated vulvar pityriasis versicolor in a 24-year-old healthy woman., Materials and Methods: A 24-year-old woman presented with variable color change on the vulva of 8 months in duration., Results: Areas of tan and white skin were observed on the mons pubis. The pubic hair had been shaved. Initially, the paler areas were deemed abnormal suggesting vitiligo, but the biopsy showed normal skin including normal numbers of melanocytes. Subsequently, biopsy of the tan area showed pityriasis versicolor. She was successfully treated with topical 2% ketoconazole, with gradual fading of lesions., Conclusions: With increased body awareness and the current popularity of pubic hair removal, young women may consult clinicians about color changes on the vulva. Clinicians should be aware that vulvar pityriasis versicolor may occur in healthy women with no other skin involvement.

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., (© 2013 The International Society of Dermatology.)

Tinea versicolor is a commonly encountered superficial fungal infection often presenting on the chest and back with hyperpigmented or hypopigmented scaly macules and patches. We report an unusual and rare presentation of tinea versicolor affecting only the eyelids., (© 2012 Wiley Periodicals, Inc.)

Background: We have observed that hair thinning and/or loss occur at times as a presenting symptom or sign in patients with pityriasis versicolor (PV)., Objective: Our objective was to verify and explore this clinical observation and depict its underlying pathology., Methods: A total of 39 patients with PV were examined during a period of 11 months and skin biopsy specimens were taken from lesional and nonlesional skin. Hematoxylin-eosin- and periodic acid-Schiff-stained sections were examined and described. Results were statistically analyzed., Results: Hair loss and/or thinning within PV lesions was shown in 61.5% of patients (P value < .0005), appearing most commonly on forearms, abdomen, and neck as well as the beard area (only in male participants). Histopathologically, in addition to the classically described features of PV, basal hydropic degeneration, follicular degeneration, miniaturization, atrophy, plugging, and/or hair shaft absence occurred in 46% of lesional versus 20.5% of nonlesional biopsy specimens (P value < .05); these changes appeared to be directly or indirectly related to the presence of Malassezia organisms in hair follicles and/or stratum corneum., Limitations: Some patients with PV lesions on the face did not approve facial biopsy., Conclusion: This study provides clinical and histopathological evidence that PV lesions may be associated with hair thinning and/or loss., (Copyright © 2012 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.)

Background: Pityriasis versicolor (PV) is a cutaneous pigmentation disorder caused by a lipophilic yeast of the genus Malassezia sp. It is a superficial mycosis characterized by well-defined, slightly scaly skin lesions of variable color. In Brazil, the number of reported cases is small, and there are few epidemiological studies., Objectives: to assess incidence, characteristics of the lesions, effectiveness of the Zileri's Sign procedure, and the epidemiological profile of PV in the urban area of Buerarema - Bahia., Methods: Biological samples were collected on pre-established days at Basic Health Care Units from July to September 2010. Sample collection was followed by laboratory diagnosis using Porto's Method., Results: Of the 158 patients with suspected PV participating in the study, 105 (66.5%) were positive; 72 (68.6%) were female and 33 (31.4%) were male. Sex and location of lesions showed statistically significant differences (p<0.05). The region with the highest rate of cases of PV was found to be the center of the city, with 40.9% of diagnosed cases. The most affected age group was between 10 and 19 years. There was a significant association between the results produced through Zileri's Sign and Porto's Method in relation to positive and negative results (p<0.05)., Conclusions: The results showed a higher prevalence of PV among individuals at puberty. The Zileri's Sign method proved to be counterproductive, because it showed low efficacy as a method for clinical diagnosis, yielding negative results for 36 (34.3%) patients who had been diagnosed with PV through laboratory examination.

Background: In healthy skin, there is a molecular microenvironment that favours the survival of melanocytes and regulates their function. Keratinocytes synthesize and secrete several cytokines that have stimulatory and inhibitory effects on melanocytes., Aim of the Work: This work was conducted to evaluate the expression of basic fibroblast growth factor (bFGF) and tumour necrosis factor alpha (TNF-α) mRNA levels in lesional skin of vitiligo, hypopigmented mycosis fungoides and hypopigmented tinea versicolor., Patients and Methods: Forty eight patients (25 vitiligo, 14 hypopigmented mycosis fungoides, 9 hypopigmented tinea versicolor) and 10 healthy controls were included. A 4 mm punch skin biopsy was taken from lesional skin of patients, and the normal skin of controls for quantitative PCR examination of TNF-α and bFGF mRNA., Results: The level of TNF-α mRNA in lesional skin of the three studied disorders was significantly higher than in the control group, while the level of bFGF mRNA was significantly lower in lesional skin of the three diseases than the control skin. A significant inverse correlation was demonstrated between the mRNA levels of the two studied cytokines in vitiligo and hypopigmented MF lesions., Conclusion: The study's findings demonstrate that the studied hypopigmented (vitiligo, hypopigmented MF, hypopigmented TV) disorders show similar changes in their cutaneous microenvironment with increased TNF-α and decreased bFGF mRNA expression. This cytokine microenvironment change may be implicated in the pigment loss and hence these cytokines may have future therapeutic implications., (© 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.)

The common superficial infection caused by Malassezia yeasts raises even today several questions concerning important pathogenetic and therapeutical aspects like an effective prevention therapy.

Tinea versicolor (TV) is a superficial cutaneous fungal infection characterized by cutaneous pigment changes, pruritus, scaling, and erythema. This open-label, single-center pilot study evaluated the efficacy and safety of naftifine 1% gel applied twice daily for 2 weeks in 10 men and women (median age 38 years) with TV. Baseline mycology status was determined by potassium hydroxide (KOH) and microscopy and clinical symptom severity (CSS) scored by the investigator using a 0 to 9 scale (0=absent, 9=worst). Patients applied naftifine HCI 1% gel to the affected area twice daily for 14 days. They returned for follow-up efficacy and safety assessments at the end of treatment (week 2), 2 weeks after treatment (week 4), and 6 weeks after treatment (week 8). All patients had a positive mycology at baseline; one was KOH negative at week 2, two were negative at week 4, and five (50%) were negative at week 8. Mean investigator total CSS score decreased from a baseline value of 4.7 to 3.2 at week 2 (32% improvement), 2.6 at week 4 (45% improvement), and 2.7 at week 8 (43% improvement). The patients rated their symptoms to be improved at all follow-up visits. There were no treatment-related adverse events during the study. These results suggest that naftifine 1% gel is a safe and efficacious topical treatment for TV.

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.

Dermatophytoses are infections caused by keratinophilic fungi known as dermatophytes. Several steps are required for infection to take place: contact, adherence, and invasion of keratin layers. The severity of the infection depends on the type of agent, environmental factors, and the host immunologic status. Tinea versicolor is caused by the Malassezia spp yeasts, which are microorganisms that belong to normal biota in seborrheic areas, but some contributing factors, such as the application of oily preparations, creams, an increase in ambient humidity, corticosteroid abuse, or genetic predisposition can induce its overgrowth in both filamentous and yeast structures. Exposure to sunlight stimulates the production of azelaic acid, which causes the appearance of hypopigmented spots. Currently, there is no scientific explanation for hyperpigmented lesions., (Copyright 2010. Published by Elsevier Inc.)

Tinea (pityriasis) versicolor is a superficial fungal infection and one of the most commonly found pigmentary disorders of skin caused by the yeast Malassezia. Multiple topical as well as systemic therapies are available for treatment. Systemic therapies are used for extensive disease, frequent relapse or where topical agents have failed. The aim that translates the rationale of the study was to compare the efficacy, safety, tolerability and cost effectiveness of single dose 400mg versus 7 day 200 mg daily dose of itraconazole in the treatment of tinea versicolor. A clinical study was done to compare the efficacy of single dose (400 mg) of itraconazole and 7 day 200 mg daily dose of itraconazole in the treatment of extensive tinea versicolor. Total 60 patients (aged 18-50 years) were selected for the study during the period of June 2007 to May 2008 in the department of Dermatology of three different hospitals in Bangladesh. Cases having with extensive involvement, diagnosed clinically and confirmed by wood's lamp and KOH microscopy were taken. Patients were randomly allocated into equal groups. Group A was given single dose 400 mg itraconazole and Group B was given 7 day 200 mg daily itraconazole. Fifty three (88%) male and 7(12%) female were included in the study. The mean age of group A was 32.37+/-9 years and in group B 33.23+/-8 years. The mean duration of the disease in group A was 2.63+/-2 months and 2.76+/-2 months in group B. In group A clinical responders was found cure 22(73.33%) and improvement 5(16.33%) and in group B it was found cure 24(79.99%) and improvement 4(13.33%). The measure at the End point (EP1) equals to 90% response and in-group B it was found cure 24 (79.99%) and improvement 4(13.33%). (Here the End point EP2) equals to 93.33%. The EP clinical analysis however shows 91.66% response. Both single dose and 7 day daily dose of itraconazole can be effective in the treatment of tinea versicolor with extensive involvement but single dose appears to be better for improving compliance and decreasing the cost of treatment.

Pityriasis versicolor is a common superficial mycoses of the skin. It is now recognized that the causative organisms of this infection are different species of Malassezia. The aim of this study was to determine the distribution of Malassezia species in patients with pityriasis versicolor in Adana, Turkey. In total, 97 patients positive for Malassezia elements, namely, yeast cells and short hyphae in microscopic examination, were included in the study. All samples were inoculated in plates containing modified Dixon's medium. However, only 44 of the patients (45.4%) showed Malassezia spp. in culture. Malassezia globosa (47.7%) was the most commonly isolated species followed by Malassezia furfur (36.4%) and Malassezia slooffiae (15.9%). Mixed Malassezia species were not isolated. In conclusion, M. globosa was found to be the predominant PV isolate in Adana, Turkey.

In our study of 6 month of pityriasis versicolor patient in skin department of Mymensingh Medical College Hospital outdoor, most of the patient was of age 16-25 years (63.33%), 20% was of age 26-35 years and 16.67% was of 36-45 years. Age distribution among male patient maximum (66.67%) was of 16-25 years and among females the maximum 50% was also of 16-25 years. Mostly was male (80%) and 20% was female only 20% of the patient has got the positive family history whereas 80% with no family history of the disease, which indicates that there is no hereditary predilection. Of the patient 66.67% was unmarried and 33.33% was married. Late adolescence & early adult age groups are predominantly affected. Small children & elderly adults are infected only in unusual circumstances, such as prolonged occlusion or immunosuppresion. Prevalence reported to be as high as 50% in the humid, hot environment of Western Samoa & on low as 11.1% in the colder temperature of Sweden. About sex distribution of patients 20% were female. The study shows that majority of patients were male (20%).

Malassezia may play a role in several dermatoses. It is responsible for foliculitis and mainly for pityriasis versicolor. Pityriasis versicolor is the most known dermatitis because of its clinical aspects and frequently for its poor response to the therapy, mainly in chronic forms. The clinical aspects of uncommon and rare forms of pityriasis versicolor have been reported. The data related to the patients observed in the last thirty years in Siena are reported. In addition, a study was carried out in Pisa by Professor F. Mancianti to identify species of Malassezia isolated in 37 patients.

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.

Yeasts of the genus Malassezia belong to the normal microflora of the human skin. In addition they are known to cause a variety of skin diseases; the most frequent of which is pityriasis versicolor. Malassezia yeasts are also thought to be associated with seborrheic dermatitis, dandruff and Malassezia folliculitis. Recently the significance of Malassezia yeasts as a trigger factor for atopic dermatitis of the head and neck region has been pointed out. The role of the Malassezia yeasts in these different diseases has been controversial in the past and remains an issue because of difficulties in isolation, culture and differentiation of the organism. Thanks to molecular techniques, 10 species can actually be differentiated. The article presents the different Malassezia-associated diseases, their clinical picture, diagnosis and appropriate therapy. In addition the speciation of Malassezia is reviewed.

The genus Malassezia is now divided into eleven species. Different species initiate or aggravate different skin diseases. In seborroheic dermatitis, M. restricta play an important role, while in atopic dermatitis, M. globosa and/or M. restricta are major cutaneous microflora. M. globosa is a causative species of tinea versicolor, and this species is also a causative species of malassezia folliculitis. We should therefore obtain better knowledge of the ecological and pathogenic roles of malassezia.

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., (Copyright (c) 2006 S. Karger AG, Basel.)

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.