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.

Dermacase. Pityriasis versicolor

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Cutaneous manifestations of systemic diseases

Many aspects of dermatologic diagnosis are either of importance or interest to the nondermatologist, and there are many excellent textbooks available for guidance. This article focuses on four categories of conditions that are the source of frequent queries from the primary care setting: (1) common skin diseases that frequently mimic systemic illness, (2) common skin diseases that have important systemic associations, (3) common systemic diseases that have prominent cutaneous findings, and (4) the seldom seen but frequently raised concerns regarding cutaneous signs of internal malignancy.

[Pityriasis versicolor in children: a retrospective study of 164 cases]

INTRODUCTION

Pityriasis versicolor is a superficial mycosis uncommonly reported in children. It occurs frequently in warm humid climates. Clinical diagnosis can be confirmed by mycology examination of a biopsy sample or a patch-test. The aim of our work was to assess the frequency of pityriasis versicolor in children in our region and ascertain the contribution of the cutaneous patch test and its diagnostic specificity.

PATIENTS AND METHODS

A retrospective analysis was conducted in patients meeting the following inclusion criteria over a 5-year period: age < 14 years, clinical presentation compatible with pityriasis versicolor, a positive patch-test. Age, sex, clinical features and favoring factors were recorded for all patients. Patch tests were performed in a control group of age-matched children with eczema or vitiligo.

RESULTS

Pityriasis versicolor was diagnosed in 1,379 cases during the study period including 164 children (11.8 p. 100). Age varied from 5 months to 14 years (mean 11 years), with a slight female predominance. Facial lesions were the most frequent (n = 78; 47.5 p. 100), preferentially on the forehead (n = 53; 68 p. 100). An achromic and hypochromic aspect predominated (n = 118; 72 p. 100). The adhesive tape tests were negative in all controls.

DISCUSSION

Pityriasis versicolor is exceptional in children in our region. The adhesive tape test provides a specific diagnostic tool. Preferential facial localization and predominant achromic and hypochromic aspect are characteristic of childhood pityriasis versicolor in our region. These 2 features are also reported in the literature. Childhood cases suggests the pathogenic factors involved in pityriasis versicolor should be reconsidered. Pityriasis versicolor should be included in the differential diagnosis of childhood hypopigmentation of the face.

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.

[Superficial mucocutaneous mycosis]

Superficial mycosis are very common. The frequency in France is 10 to 15% of the population. The reason for the high incidence of this disease is the change of the moral values, rise in promiscuity and increase sports activities. The agents responsible are divided in four groups. Dermatophytes involve keratin of the skin, hairs and nails but never the mucous membranes. They can cause glabrous skin lesion, tinea corporis, tinea capitis or onychomycosis. Yeast are divided in two groups: the candidiasis and Malassezia furfur, the etiologic agent of pityriasis versicolor. Oral mucosa candidiasis is very common in HIV infected patients.

Diagnosis and treatment of tinea versicolor

Tinea versicolor (pityriasis versicolor) is a common superficial fungal infection of the stratum corneum. Caused by the fungus Malassezia furfur, this chronically recurring disease is most prevalent in the tropics but is also common in temperate climates. Treatments are available and cure rates are high, although recurrences are common. Traditional topical agents such as selenium sulfide are effective, but recurrence following treatment with these agents is likely and often rapid. Currently, therapeutic interest is focused on synthetic "-azole" antifungal drugs, which interfere with the sterol metabolism of the infectious agent. Ketoconazole, an imidazole, has been used for years both orally and topically with great success, although it has not been approved by the Food and Drug Administration for the indication of tinea versicolor. Newer derivatives, such as fluconazole and itraconazole, have recently been introduced. Side effects associated with these triazoles tend to be minor and low in incidence. Except for ketoconazole, oral antifungals carry a low risk of hepatotoxicity.

A single method to stain Malassezia furfur and Corynebacterium minutissimum in scales

The scales are collected by pressing small pieces of scotch tape (about 4 cm length and 2 cm width) onto the lesions and following withdrawal the furfuraceous scales will remain on the glue side. These pieces are then immersed for some minutes in lactophenol-cotton blue stain. Following absorption of the stain the scales are washed in current water to remove the excess of blue stain, dried with filter paper, dehydrated via passage in two bottles containing absolute alcohol and then placed in xylene in a centrifugation tube. The xylene dissolves the scotch tape glue and the scales fall free in the tube. After centrifugation and decantation the scales concentrated on the bottom of the tube are collected with a platinum-loop, placed in Canada balsam on a microscopy slide and closed with a cover slip. The preparations are then ready to be submitted to microscopic examination. Other stains may also be used instead of lactophenol-cotton blue. This method is simple, easily performed, and offers good conditions to study these fungi as well as being useful for the diagnosis of the diseases that they cause.

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.

Tinea versicolor of the scalp

BACKGROUND

Tinea versicolor (TV) is commonly described on the trunk without giving attention to involvement of the scalp. We examined cases with dandruff with and without TV on the body to see how frequent Malassezia furfur (M. furfur) is present in dandruff scales.

METHODS

A total of 80 patients were examined mycologically using KOH preparation for the presence of M. furfur in dandruff scales.

RESULTS

M. furfur was found in dandruff scales in 7 out of 20 men with TV (35%) and 5 out of 20 women with TV (25%), whereas it was absent in another 40 cases without clinical lesions of TV on the body.

CONCLUSIONS

Attention must be paid to TV of the hairy scalp. Cases of dandruff, especially those accompanied with TV of the body, must be examined for the presence of M. furfur because of its prognostic significance. Positive cases should be treated accordingly.