Lipoperoxidase activity of Pityrosporum: characterisation of by-products and possible rôle in pityriasis versicolor

Abstract Modification of pigmentation and damage of melanocytes are characteristic features of skin colonisation by Pityrosporum orbiculare hyphae in pityriasis versicolor (PV). The yeast is lipophylic and lipid-dependent, capable of oxidising unsaturated lipid components of skin surface, i.e. unsaturated fatty acids, cholesterol and squalene (SQ). The oxidation of unsaturated fatty acids gives rise to dicarboxylic acids (DA) which behave, in vitro, as competitive inhibitors of tyrosinase. In this work, we further investigate the oxidase activity of Pityrosporum in vitro, by evaluating (a) the generation of lipoperoxides in cultures supplemented with fatty acids at various degrees of unsaturation; (b) the mechanism of SQ oxidation; (c) the chemical characteristics of some by-products of lipoperoxidation; (d) the formation of peroxisomes in fungal cells. In cultures supplemented with the saturated palmitic acid (C16:0) and monounsaturated oleic acid (C18:1 n-9), low amounts of lipoperoxides were detected by a spectrophotometric test, whereas in cultures supplemented with di-unsaturated linoleic acid (C 18:2 n-6), significant concentrations were found. Gas chromatographymass spectrometry analyses showed the generation of linoleic acid hydroperoxides both in Pityrosporum cultures and following incubation of acetone powder of the fungus with the unsaturated fatty acid, indicating the presence of a lipoxygenase activity in the fungus. In cultures supplemented with linoleic acid plus SQ, and increase of lipoperoxide generation was observed and trans-trans farnesal and squalene epoxides have been identified. Electron microscopic examinations have evidenced peroxisomes in cells grown in the presence of linoleic acid, whereas they were not delected in cultures supplemented with oleic acid and palmitic acid. The metabolic activities of peroxisomes, through the formation of hydrogen peroxide and the subsequent generation of hydroxyl radicals, may account for the peroxidation of SQ, which is not a substrate of lipoxygenase. Following these results, we propose a mechanism for DA generation by Pityrosporum metabolism and hypothesize that the lipoperoxidation process induced by lipoxygenase activity of the fungus may be the key to understanding the clinical appearance of skin manifestation of PV.     

Predisposing factors on the surface of the skin in persons with pityriasis versicolor

This is a report on biochemical and physiological examinations carried out on 20 test persons who in the last 2 years had contacted and completely recovered from pityriasis versicolor and on 25 control persons of corresponding age and sex. The tests on the skin surface of the patients with pityriasis versicolor show, when compared with the corresponding control group, the following significant results: 1. Significantly more amino acids could be extracted from the skin of the pityriasis versicolor patients than from the skin of the control persons. 2. A significantly shorter alkali neutralisation time was to be found in the pityriasis versicolor patients than in the control persons. 3. The degree of water spreading on the skin was found to be significantly reduced in the pityriasis versicolor patients when compared with the control persons. It is probable that these results point to important predisposing factors for pityriasis versicolor.     

IgE antibodies to Malassezia furfur, M. sympodialis and Pityrosporum orbiculare in patients with atopic dermatitis, seborrheic eczema or pityriasis versicolor, and identification of respective allergens

Malassezia yeasts may be a trigger factor for atopic dermatitis. Following the recent reclassification of the genus, the presence of specific IgE antibodies was examined in the sera of patients with atopic dermatitis (n = 223), pityriasis versicolor (n = 83), seborrheic eczema (n = 50) and hymenoptera allergy (n = 39) and in controls without skin diseases (n = 50). In addition to using the commercially available radioallergosorbent test (RAST) for Pityrosporum orbiculare couplings were also made against the reference strains for M. furfur and M. sympodialis. To characterize the specificity and molecular weight of corresponding epitopes identical material was used for production of an immunoblot. Despite high total levels of IgE, controls and patients with pityriasis versicolor showed no specific IgE antibodies. Six patients (12%) with seborrheic eczema were positive while 78 patients (35%) with atopic dermatitis had specific IgE antibodies in higher RAST classes that differed between the Malassezia species. The molecular weights of the main antigens of M. sympodialis and M. furfur were determined to be 15, 22, 30, 37, 40, 58, 79, 92, 99 and 124 kDa and 15, 25, 27, 43, 58, 92, 99 and 107 kDa, respectively. Evaluated according to the location of their disease, patients with head and neck lesions most frequently showed Malassezia-specific IgE antibodies. However, there were differences between the Malassezia species tested, the previously used strain P. orbiculare being assignable to the species M. sympodialis.     

Pityriasis (Tinea) Versicolor in Infancy

Pityriasis (tinea) versicolor is a common disorder of adults. We cared for five infants (four males and one female) with the disease. Diagnosis was confirmed by potassium hydroxide preparation demonstrating the filaments of Malassezia furfur and/or Pityrosporum orbiculare, the yeast form. Three patients had lesions in the neonatal period. The mother of one baby had pityriasis versicolor. Two patients were siblings. One baby had associated atopic dermatitis and two had a positive family history of atopy.     

PITYRIASIS VEESICOLOR: A CLINICAL AND MYCOLOGICAL INVESTIGATION

SUMMARY. Twenty-five patients with pityriasis versicolor have been studied clinically and mycologically and the hospital records of a further 62 patients have been analysed. The sex ratio for the whole series was 3 males to 2 females, the age of onset was usually in the early twenties. Nearly all cases in the Cambridge area start in the warmer months of the year. Conjugal cases are reported but a genetic factor in susceptibility is also accepted. Attention is drawn to the extent of the lesions on the limbs and flexural involvement in association with excessive sweating is shown to be common. Pityrosporum orbiculare was cultured from the lesions of 25 of 27 patients and its presence was also detected on uninvolved skin. The evidence for the identity of P. orbiculare and Malassezia furfur is reviewed briefly and the analogy is drawn with yeast/mycelium transition in candidiasis. The ecology of P. orbiculare/M. furfur in pityriasis versicolor is discussed in the light of the results presented.     

Intertriginous lesions in pityriasis versicolor

BACKGROUND: 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. OBJECTIVES: To study the occurrence and morphology of lesions of pityriasis versicolor in flexural areas. METHODS: One hundred and ten cases of pityriasis versicolor were studied. Sites of lesions and other clinical features were determined. RESULTS: Flexural lesions in pityriasis versicolor were not uncommon. They were not correlated to age, sex, duration or relapses of the infection. CONCLUSION: 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.     

Changes in fungal ultrastructure after short-course ciclopiroxolamine therapy in pityriasis versicolor

The clinical outcome and the effects on morphogenesis and cell ultrastructure induced by a 1% ciclopiroxolamine solution in six patients with proven pityriasis versicolor were studied. Treatment regimens consisting of a once-daily application for 1 day, 2 days (Days 1 and 4) or 3 days (Days 1, 4 and 8). Clinical evaluation, scanning (SEM) and transmission electron microscopy (TEM) were performed on skin scrapings before treatment, and at 3, 7, 15 and 21 days after the start of therapy. SEM techniques have shown severe changes in the surface ultrastructure of yeasts and hyphae of Pityrosporum spp. (Malassezia furfur) 15 days after the start of therapy. TEM techniques showed extensive internal disruption, mainly severe necrosis of the cytoplasm, 3 and 7 days after the start of treatment. However, KOH direct microscopy showed apparently normal morphology of Pityrosporum spp. (Malassezia furfur) at all assessment points. The final clinical cure in all the patients was achieved 21 days after the start of therapy.     

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.     

An immunological study in patients with seborrhoeic dermatitis

The humoral and cellular immune-status was studied in 30 patients with seborrhoeic dermatitis. Increased frequencies of natural killer cells were found in 46% of patients. Furthermore, subnormal mitogen stimulation responses were demonstrated in 13 patients, whereas two individuals were found to have very high numbers of activated T lymphocytes in peripheral blood. Higher-than-normal total serum IgG and IgA was observed in 14 and 11 patients, respectively. For nine of 12 patients with skin lesions, dermal perivascular cell infiltrates were seen. The majority of the infiltrating cells reacted with anti-CD4 antibodies. HLA-DR-expressing keratinocytes were found in two biopsies. The study suggests that patients with seborrhoeic dermatitis may have depressed T-cell function. This could have a bearing on their susceptibility to the Pityrosporum ovale-associated dermatitis. The very high frequencies of activated T cells observed in the peripheral blood of two otherwise healthy seborrhoeic individuals suggests that intermittent systemic immune activation may occur. Seborrhoeic dermatitis is a common skin disease. It can be diagnosed by its characteristic red to yellow-brown lesions covered with greasy scales distributed in areas with a high number of sebaceous glands, such as the scalp, face and upper trunk. There is an association between seborrhoeic dermatitis and the lipophilic yeast Pityrosporum ovale but its exact aetiological role is not known. The yeast is a member of the normal cutaneous flora but also the aetiological agent of pityriasis versicolor and Pityrosporum folliculitis. P. ovale can activate complement via the direct and alternative pathways. This may play some part in the induction of inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)     

花斑癣患者血清中抗糠秕马拉色菌IgG、IgM、IgA抗体的检测及其意义

目的：探讨机体体液免疫在花斑癣发病中的作用和意义。方法：以糠秕马拉色菌（Ｍ．ｆｕｒｆｕｒ）整菌（ＷＭＦ）为抗原,用间接酶联免疫吸附试验（ＥＬＩＳＡ）方法,检测６８例花斑癣患者和４１例正常人血清中的抗ＷＭＦ抗体。结果：正常人血清中存在高滴度的抗ＷＭＦ抗体,花斑癣患者血清中抗ＷＭＦＩｇＧ抗体明显低于正常对照组（Ｐ〈０．０１）,男性患者血清中ＩｇＧ抗体低于女性患者（Ｐ〈０．０１）,病程１年以上者血清中特异的ＩｇＧ抗体低于病程不到１年者（Ｐ〈０．０１）。结论：机体血清抗Ｍ．ｆｕｒｆｕｒ抗体可能是人体内天然抗体,且特异的ＩｇＧ抗体具有保护作用。支持花斑癣的发病与免疫缺陷有关。     

Pityriasis versicolor in Greece and its predisposition factors]

The age and seasonal incidence of 2610 patients with pityriasis versicolor in Greece were studied. Determination of the pH of Na and K ions of the sweat and the microbiol flora of the skin of pityriasis versicolor patients was undertaken. Besides these the effectiveness of a 1% selenium disulfid suspension was tested. The results indicate that the age groups of 20-29 and 30-30 years are mostly affected by the disease. A high incidence of the skin manifestation was noted during the summer and fall months. A difference of the pH of the sweat between pityriasis versicolor and healthy controls was observed, but no difference was found in the Na and K ions of the sweat among these two groups. Neither did the microbial flora from the skin lesions of patients and from corresponding sites of controls show any difference. The high relapse in this experiment indicates the relative ineffectiveness of selenium disulfid preparations when used as a 1% suspension in the treatment of pityriasis versicolor.     

HYPHAL PRODUCTION BY PITYROSPORUM OVALE

Pityrosporum ovale with abundant hyphae was found in 8 patients with lesions of the scalp and glabrous skin. It is thought that P. ovale in its mycelial form can produce lesions on seborrheic areas of the skin that probably represent a clinical form of tinea versicolor.     

Skin Characteristics in Patients with Pityriasis Versicolor Using Non-Invasive Method, MPA5

Background

Skin pigmentary changes of pityriasis versicolor may occur as either hyperpigmented or hypopigmented lesions, depending on the outcome of interactions between Malassezia yeasts and the skin, such as lipoperoxidation process, stimulus of inflammatory cell to melanocytes, and increased thickness of keratin layer.

Objective

To investigate skin characteristic factors that enhance the susceptibility to Malassezia yeasts and provoke different color changes of pityriasis versicolor patients.

Methods

To clarify these factors, we investigated the skin characteristics of pityriasis versicolor patients, using a non-invasive method known as MPA 5® (Courage and Khazaka, Germany). A total of 90 normal healthy subjects and 30 pityriasis versicolor patients were included in this study.

Results

Both hyperpigmented and hypopigmented pityriasis versicolor skin lesions showed higher humidity, increased sebum excretion rate and increased transepidermal water loss (TEWL) values than normal healthy subjects. But no significant difference of specific Malassezia yeasts species between hyperpigmented and hypopigmented skin lesions was evident.

Conclusion

These results indicate that higher humidity and increased sebum level provide a better growing environment of Malassezia yeasts in the skin, leading to the assumption that interaction between Malassezia yeasts and skin barrier materials makes disruption of skin barrier causing increased TEWL.     

马拉色菌与花斑癣色素改变的相关性初探

目的探讨马拉色菌与花斑癣皮疹色素改变及色氨酸产色三者之间的关系.方法从花斑癣患者皮损分离马拉色菌株,采用国际通用的生化鉴定方法鉴定,然后在不同浓度L-色氨酸的培养基上培养7 d,观察产色反应.结果每个菌种均有产色反应阳性和阴性菌株,产色反应阳性菌株更易引起皮损色素沉着(P＜0.005),且产色反应阳性标本颜色按色氨酸浓度递减而变淡.结论菌株的产色反应与马拉色菌的种属分类无必然的联系,色氨酸参与了马拉色菌产色反应.     

Hypopigmented pityriasis versicolor on Becker's naevus : Hope for new method of treatment ?

A case of hypopigmented pityriasis versicolor superimposed on pre existing Becker's naevus associated with congenital melanocytic naevus is being reported for its rarity. The possible role of dicarboxylic acid and other free radicles produced by Pityrosporum ovale in treating Becker's Naevus is also suggested.     

Management of Seborrheic Dermatitis and Pityriasis Versicolor

Pityriasis (tinea) versicolor and seborrheic dermatitis are two very common skin diseases. Pityriasis versicolor is a chronic superficial fungal disease usually located on the upper trunk, neck, or upper arms. In pityriasis versicolor, the lipophilic yeast Malassezia (also know as Pityrosporum ovale or P. orbiculare) changes from the blastospore form to the mycelial form under the influence of predisposing factors. The most important exogenous factors are high temperatures and a high relative humidity which probably explain why pityriasis versicolor is more common in the tropics. The most important endogenous factors are greasy skin, hyperhidrosis, hereditary factors, corticosteroid treatment and immunodeficiency. There are many ways of treating pityriasis versicolor topically. Options include propylene glycol, ketoconazole shampoo, zinc pyrithione shampoo, ciclopiroxamine, selenium sulfide, and topical antifungals. In difficult cases, short term treatment with fluconazole or itraconazole is effective and well tolerated. To avoid recurrence a prophylactic treatment regimen is mandatory. Seborrheic dermatitis is characterized by red scaly lesions predominantly located on the scalp, face and upper trunk. There are now many studies indicating that Malassezia plays an important role in this condition. Even a normal number of Malassezia will start an inflammatory reaction. Mild corticosteroids are effective in the treatment of seborrheic dermatitis. However, the disease recurs quickly, often within just a few days. Antifungal therapy is effective in the treatment of seborrheic dermatitis and, because it reduces the number of Malassezia, the time to recurrence is increased compared with treatment with corticosteroids. Antifungal therapy should be the primary treatment of this disease.     

Prevalence of pityriasis versicolor in young Italian sailors

BACKGROUND: Pityriasis versicolor is a superficial fungal disease with a world-wide distribution, but there are few available studies on its prevalence in the general population. OBJECTIVES: To assess the prevalence of pityriasis versicolor in a representative sample of young Italian sailors, evaluating the influence of habits and risk factors in the affected individuals. METHODS: Young cadets (n = 1024: 975 men and 49 women, mean age 22 years) of the Italian Navy Petty Officers' School in Taranto were consecutively examined by the same observer. The diagnosis of pityriasis versicolor was based on clinical picture and/or Wood's lamp examination. All the subjects filled in a questionnaire about sport practice, swimming pool attendance, marching, presence of hyperhidrosis and a positive clinical history of pityriasis versicolor in the past. The affected individuals were also asked if they were aware of their skin lesions. Differences between answers of affected and unaffected subjects were tested by Fisher's exact P-value test, and odds ratios were calculated. RESULTS: Pityriasis versicolor was diagnosed in 22 subjects (2.1%), all men, of whom 15 (68%) were not aware of their condition. No statistical association was found between active pityriasis versicolor and sport practice, swimming pool attendance, marching or presence of hyperhidrosis. A significant association [odds ratio 8.7 (95% confidence interval 3.3-21.5); Fisher's exact P-value test P < 0.01] was documented between active pityriasis versicolor and a previous clinical history of pityriasis versicolor. CONCLUSIONS: The prevalence of pityriasis versicolor in this sample of young Italian sailors was not high, in agreement with the available surveys performed in the general population in temperate climates. Many affected subjects were not aware of their condition. The only important factor associated with pityriasis versicolor was a previous history of pityriasis versicolor. This observation could confirm the hypothesis that constitutional factors, e.g. seborrhoea and chemical constitution of sebum, may play a crucial role in temperate climates, leading to relapsing forms of this superficial mycosis.     

Cell-mediated immunity to the mycelial phase of Malassezia spp. in patients with pityriasis versicolor and controls

BACKGROUND: Malassezia is the aetiological agent of pityriasis versicolor. The mycelial phase of the organism predominates in lesions of pityriasis versicolor. OBJECTIVES: To evaluate the cell-mediated immune (CMI) response to the mycelial phase of Malassezia in patients with this disease, which has not previously been studied. METHODS: The CMI status of 12 patients with pityriasis versicolor and 12 age- and sex-matched controls to mycelial antigen(s) of the organism was examined. The responses to the mycelial form of three strains of the organism were assessed using lymphocyte transformation and leucocyte migration inhibition assays. RESULTS: The transformation responses of the lymphocytes from both patients and controls gave transformation indices < or = 3, although the responses of lymphocytes from patients with pityriasis versicolor to the mycelial form of Malassezia strains were generally higher than those of the controls. In the leucocyte migration inhibition assay, leucocytes from patients with pityriasis versicolor and controls responded to the mycelial antigens of three different Malassezia strains; however, there was no significant difference in leucocyte response between patients with pityriasis versicolor and controls. CONCLUSIONS: Patients with pityriasis versicolor do not therefore have a CMI deficiency to Malassezia mycelial antigens but fail to generate a protective CMI response to mycelial antigens over and above that of control individuals during active disease.     

SKIN SURFACE LIPIDS IN HIV-POSITIVE PATIENTS WITH AND WITHOUT SEBORRHEIC DERMATITIS

Background. Seborrheic dernnatitis (SD) is a frequent complication of infection with the human immunodeficiency virus (HIV). Most studies examining the cause of SD have concentrated on the roles of Pityrosporum ovale and sebaceous lipids. Previous studies of skin surface lipid from patients with SD have produced conflicting results, with some authors reporting an abnormal lipid composition and others finding little or no abnormality. Methods. The composition of skin surface lipid was studied in 15 HIV-positive and 10 HIV-negative men with SD, in 14 HIV-positive men without SD, and in 16 unaffected controls. Total lipids were extracted from unaffected forehead skin into petroleum ether and separated into lipid classes by thin layer chromatography. The lipid classes were quantitated by densitometry after charring with sulfuric acid. Results. Patients, HIV-positive with SD, had significantly lower proportions of free fatty acid (FFA) and higher levels of triglyceride than normal controls. Patients, HIV-positive without SD, had a significantly increased proportion of FFA compared to HIV-positive patients with SD. Patients with SD, both HIV-positive and HIV-negative, had a similar pattern of skin surface lipid. Levels of FFA were lower and those of triglyceride higher than in the patients unaffected by SD, whether HIV-positive or not. There was no significant difference found between groups in free cholesterol, wax esters, and squalene. Conclusions. Abnormalities of skin surface lipid composition may play a part in the development of SD in both HIV-positive and HIV-negative men.     

Analyses of skin surface lipid in patients with microbially associated skin disease

The composition of the total skin surface lipid, free fatty acids and fatty acid of triglyceride was used in discriminant analyses to classify patients with severe acne vulgaris (AY), pityriasis versicolor (PV), seborrhoeic dermatitis (SD) and atopic dermatitis (AD). It was not possible to discriminate between the PV and SD patients but alt the lipid groups gave a satisfactory separation between AV, PV + SD and AD patients. A similar separation was obtained when the sex of the patient was studied but not when both sex and disease were taken into account. The results suggest that there are fundamental differences in the composition of skin lipid between patients with microbially associated diseases, but the precise role of the organisms has not been ascertained.