Isolation of dermatophytes, Candida species and systemic fungi from dermatologic specimens in Montreal, 1963 to 1973.
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Of 10 057 specimens of scrapings from skin, nails and scalp examined for dermatophytes, yeasts, pityriasis versicolor and systemic mycoses between 1963 and 1973, 30.4 percent were positive for fungi. Skin produced the highest proportion (68.6 percent) of positive scrapings, scalp the lowest (4.2 percent). Trichophyton rubrum was the predominant species (23.6 percent); of lesser prevalence were Microsporum canis (9.3 percent), T. mentagrophytes (8.4 percent) and Epidermophyton floccosum (4.8 percent). Double infections were encountered on 102 occasions; T. rubrum and Candida parapsilosis were the most frequent cohabiting species. The introduction in 1966 of periodic acid-Schiff staining for routine examination of scrapings resulted in better diagnostic results, particularly in the case of culturally nonproductive specimens and cases of pityriasis versicolor. Blastomyces dermatitidis and Cryptococcus neoformans were isolated from two patients in the course of routine investigation for dermatophytes. (+info)
Immunology of diseases associated with Malassezia species.
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Malassezia species are members of the human cutaneous commensal flora, in addition to causing a wide range of cutaneous and systemic diseases in suitably predisposed individuals. Studies examining cellular and humoral immune responses specific to Malassezia species in patients with Malassezia-associated diseases and healthy controls have generally been unable to define significant differences in their immune response. The use of varied antigenic preparations and strains from different Malassezia classifications may partly be responsible for this, although these problems can now be overcome by using techniques based on recent work defining some important antigens and also a new taxonomy for the genus. The finding that the genus Malassezia is immunomodulatory is important in understanding its ability to cause disease. Stimulation of the reticuloendothelial system and activation of the complement cascade contrasts with its ability to suppress cytokine release and downregulate phagocytic uptake and killing. The lipid-rich layer around the yeast appears to be pivotal in this alteration of phenotype. Defining the nonspecific immune response to Malassezia species and the way in which the organisms modulate it may well be the key to understanding how Malassezia species can exist as both commensals and pathogens. (+info)
Isolated scalp involvement with pityriasis versicolor alba (pityrias versicolor albus capitis) in a patient from a dry, temperate region.
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Pityriasis versicolor (tinea versicolor) is a common superficial fungal infection of the skin involving the hyphal (filamentous) form of Pityrosporum orbiculare. Clinical cutaneous infection is common in humid, tropical climates, but declines to less than 5 percent in temperate climates. Isolated face or scalp involvement is rare. We present a boy living in a temperate region who had sudden onset of scalp and hairline involvement with tinea versicolor. (+info)
Common hyperpigmentation disorders in adults: Part II. Melanoma, seborrheic keratoses, acanthosis nigricans, melasma, diabetic dermopathy, tinea versicolor, and postinflammatory hyperpigmentation.
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Nevi, or moles, are localized nevocytic tumors. The American Cancer Society's "ABCD" rules are useful for differentiating a benign nevus from malignant melanoma. While acanthosis nigricans may signal an underlying malignancy (e.g., gastrointestinal tumor), it more often is associated with insulin resistance (type 2 diabetes, polycystic ovary syndrome) or obesity. Melasma is a facial hyperpigmentation resulting from the stimulation of melanocytes by endogenous or exogenous estrogen. Treatments for melasma include bleaching agents, laser therapy, and a new medication that combines hydroquinone, tretinoin, and fluocinolone acetonide. Lesions that develop on the shins of patients with diabetic dermopathy often resolve spontaneously; no treatment is effective or recommended. Tinea versicolor responds to treatment with selenium sulfide shampoo and topical or oral antifungal agents. Postinflammatory hyperpigmentation or hypopigmentation can occur in persons of any age after trauma, skin irritation, or dermatoses. (+info)
Study of the distribution of Malassezia species in patients with pityriasis versicolor and healthy individuals in Tehran, Iran.
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BACKGROUND: Pityriasis 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. METHODS: Differentiation of all malassezia species performed using morphological features and physiological test including catalase reaction, Tween assimilation test and splitting of esculin. RESULTS: In 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. CONCLUSIONS: According 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. (+info)
Apolipoprotein E gene polymorphism and serum lipids in patients with superficial fungal disease.
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Superficial mycosis, including dermatophytic infections, tinea versicolor, and cutaneous candidiasis is mostly limited to the outer layers of the skin, nails, and mucous membranes. In this study, Apolipoprotein E (ApoE) polymorphism and lipoprotein cholesterol concentrations were compared between 42 patients with superficial fungal disease and 27 control subjects. Both the patients and controls were found to be normolipemic. The patients with superficial fungal disease had significantly higher concentrations of high-density cholesterol (HDL) compared to the control group (p=0.0462). However, there was no difference in the serum triglyceride, low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) cholesterol concentrations. A significantly higher incidence of heterozygosity E2/3 was found in the patients (p=0.0228), and significantly lower incidence of homozygosity E3/3 in all patients, and those with candidiasis and dermatophytosis (p=0.0139, 0.0194 and 0.0337, respectively) compared to the control group. The E3/4 genotype differences between patients and controls were not statistically significant. There were slight differences in the allele frequencies between the two groups, but these did not reach statistically significant levels. It was concluded that the presence of apoE2/3 genotype, high HDL-cholesterol levels and the absence of apoE3/3 genotype can be regarded as risk factors for superficial fungal disease, especially dermatophytosis. (+info)
Superficial fungal infections seen at the National Skin Centre, Singapore.
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Cutaneous fungal infections are common in Singapore. The National Skin Centre is a tertiary referral centre for dermatological diseases in the country, and sees more than 2,500 cases of superficial fungal infections annually. AIM: This study analyses data collated from the centre's medical record office as well as fungal culture results from the mycology laboratory. RESULTS: From 1999 to 2003, there were a total of 12,903 cases of superficial fungal infections seen at the centre. The majority of patients (n=9335) (72.3%) were males. The most common infection was tinea pedis (n=3516) (27.3%), followed by pityriasis versicolor (n=3249) (25.2%) and tinea cruris (n=1745) (13.5%). Candidal infections were also common (n=1430), the majority of which were cases of candidal intertrigo. There were very few cases of tinea capitis, which is uncommon in Singapore. The number of cases of onychomycosis has shown a rising trend over the past 5 years. Trichophyton rubrum was the most prevalent fungal pathogen isolated from all cases of superficial fungal infections of the skin, except for tinea pedis, where Trichophyton interdigitale was the most frequently isolated organism. Dermatophytes remain the most commonly isolated fungal pathogens isolated in toenail onychomycosis, whilst Candida species accounted for the majority of isolates in fingernail onychomycosis. CONCLUSION: Current epidemiologic trends of superficial fungal infections in Singapore show some similarities to recent studies from the United Kingdom and United States. (+info)
Sparing of the upper axillary area in pityriasis versicolor.
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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. (+info)