Malassezia skin diseases in humans.

Although Malassezia yeasts are a part of the normal microflora, under certain conditions they can cause superficial skin infection, such as pityriasis versicolor (PV) and Malassezia folliculitis. Moreover the yeasts of the genus Malassezia have been associated with seborrheic dermatitis and dandruff, atopic dermatitis, psoriasis, and, less commonly, with confluent and reticulated papillomatosis, onychomycosis, and transient acantholytic dermatosis. The study of the clinical role of Malassezia species has been surrounded by controversy due to the relative difficulty in isolation, cultivation, and identification. This review focuses on the clinical, mycologic, and immunologic aspects of the various skin diseases associated with Malassezia. Moreover, since there exists little information about the epidemiology and ecology of Malassezia species in the Italian population and the clinical significance of these species is not fully distinguished, we will report data about a study we carried out. The aim of our study was the isolation and the identification of Malassezia species in PV-affected skin and non-affected skin in patients with PV and in clinically healthy individuals without any Malassezia associated skin disease.

Skin diseases associated with Malassezia species in humans. Clinical features and diagnostic criteria.

Malassezia yeasts not only cause the well known pityriasis versicolor and folliculitis, but also play an important role in other skin diseases, including seborrheic dermatitis and atopic dermatitis. The presence of Malassezia yeasts may be confirmed by direct microscopic examination and cultures of skin scrapings. In pityriasis versicolor the direct microscopic examination is the rapidest and surest test for confirming the clinical diagnosis. The preparation will show a cluster of globose budding spores with thick or double wall and short hyphae. For detecting Malassezia in the other diseases the cultures is preferable. Culture is useful both for confirming the clinical diagnosis and for epidemiological investigations. The identification of the Malassezia species is not easy. The microscopic observation of the colony direct towards the identification of Malassezia species, but it is not enough to identify the colonies definitely. Several biochemical tests are necessary for a precise identification, such as catalase reaction, growth on media without lipid sources, ability to utilize hydrophilic emulsifiers as sole lipid source, esculin test, tryptophan test.

Subcutaneous alternariosis.

A case of subcutaneous alternariosis caused by Alternaria alternata is reported in a 52-year-old male who underwent kidney transplantation 1 year earlier. The infection manifested as a vegetating mass about 7 cm in diameter on the right forearm. Histological examination with Grocott staining and periodic acid-Schiff diastase revealed fungal spores and hyphae with chronic granulomatous inflammation. Biopsy fragments inoculated on Sabouraud-glucose agar with chloramphenicol produced colonies which were identified as Alternaria alternata on the basis of macroscopic and microscopic characters.

The treatment of basal cell carcinomas in a patient with xeroderma pigmentosum with a combination of imiquimod 5% cream and oral acitretin.

Xeroderma pigmentosum (XP) is a rare autosomal recessive photosensitive disorder, which results in multiple face, neck and head basal cell carcinomas (BCCs), squamous cell carcinomas and melanomas. A 15-year-old boy with XP presented with multiple facial BCCs previously treated by surgical excision. Standard BCC treatments such as surgery are not ideal for patients with several facial BCCs because of the risk of scarring, and the patient refused further surgery. As an alternative, three times weekly application of imiquimod 5% cream in combination with oral acitretin (20 mg daily) was prescribed for 4-6 weeks. No adverse events were reported during treatment and all tumours had resolved at the 6-month follow up visit, highlighting the therapeutic potential of imiquimod 5% cream.

Onychomycosis caused by Alternaria spp. in Tuscany, Italy from 1985 to 1999.

Cutaneous phaeohyphomycosis due to Alternaria spp. is reported with increasing frequency, especially in patients with immune deficiency. Onychomycosis caused by this mould is still rarely observed. Here we report nine cases observed in Tuscany in the period 1985-99; the agent was Alternaria alternata in eight cases and Alternaria chlamidospora in one. Diagnosis was made on the basis of repeated direct microscopic mycological examination and culture, confirmed by scanning electron microscope observation of fragments of colonies. In most cases, the clinical manifestations were dystrophy and distal subungual hyperkeratosis of one or two nails of the feet or hands. Seven cases were treated with oral itraconazole, successfully in six cases, as clinical and mycological recovery was confirmed at follow-up 1 year later.

Dermatophytosis due to Trichophyton violaceum in Tuscany from 1985 to 1997.

We describe 45 cases of dermatophytosis due to Trichophyton violaceum diagnosed in Tuscany from 1985 to 1997. Diagnosis was based on direct microscope mycological examination and culture. Nine of the 45 patients were Italian, eight of whom were born and resident in Tuscany; the others were Africans who contracted the infection in their country of origin. The first case in a non-European was observed in 1985, but since 1991 isolation from foreigners has become more frequent. The increase in cases of infection by T. violaceum in our region is certainly linked to immigration. The cases of epidermomycosis in Tuscans suggests that the fungus has already become autochthonous.

Two cases of tinea pedis caused by Scytalidium hyalinum.

Two cases of tinea pedis due to Scytalidium hyalinum, the first to be described in Italy, are reported. The patients were a 41-year-old woman and a 35-year-old man who had spent periods in the Caribbean. The clinical manifestations were indistinguishable from those caused by dermatophytes. In the women they were striking with 'moccasin foot' type lesions, whereas in the man they were less evident, with minor plantar desquamation and interdigital maceration. Diagnosis was based on direct mycological microscopic examination and culture. Clinical and mycological remission were obtained with systemic itraconazole therapy. These cases are reported because infections caused by Scytalidium hyalinum are rare in Europe and their clinical and mycological diagnosis, as well as therapy, may be problematic.

Skin and nail infections due to Fusarium oxysporum in Tuscany, Italy.

Nine cases of skin and nail infection due to Fusarium oxysporum, diagnosed in Tuscany in the period 1985-97, are described. Two manifested as interdigital intertrigo of the feet and seven as onychomycosis. All were diagnosed on the basis of repeated mycological examination, direct microscope observation and culture, as well as histological examination of biopsy specimens in two cases of intertrigo. Fragments of the fungal colonies were examined by scanning electron microscopy (SEM) for more detailed observation of fungal morphology. All patients had normal immune status and a history of the infection extending several years. Four of the patients with onychomycosis were treated with oral itraconazole, and clinical and mycological recovery was achieved in three cases. Two others were treated with cyclopyrox nail lacquer, successfully in one case. One patient with intertrigo was treated with oral itraconazole and one with oral terbinafine; both were also treated and with topical drugs, however clinical recovery was not confirmed by the mycological results.

Two cases of cutaneous phaeohyphomycosis by Alternaria alternata and Alternaria tenuissima.

Two cases of cutaneous phaeohyphomycosis, one with a nodular appearance and the other with an erythematous infiltrating patch, are reported in immunocompromised patients. Diagnosis was based on histological examination, which revealed hyphae and round-shaped fungal cells in a granulomatous dermal infiltrate, and on identification of the moulds when biopsy fragments were cultured on Sabouraud-dextrose agar without cycloheximide. The pathogens were Alternaria tenuissima in the first case and A. alternata in the second. The fungi were examined by scanning electron microscopy. The patients were checked for bone and lung involvement and were then treated with surgical excision and itraconazole, and itraconazole only, respectively, with clinical and mycological resolution.

Tinea capitis in the Florence area between 1985 and 1993.

This paper describes the main epidemiological findings in 203 patients with tinea capitis and in seven other patients with dermatophytosis that had also extended to the scalp. The patients were observed over a 9-year period (from 1985 to 1993) at the Department of Dermatology of the University of Florence. Tinea capitis was the fourth most frequent dermatophytosis. Most of the patients were children, although 23 were adults. The most frequent aetiological agent was Microsporum canis. It is interesting to note that there were 12 cases of tinea capitis due to Trichophyton violaceum in African immigrants. This dermatophyte was believed to have disappeared from Italy. One case was due to Epidermophyton floccosum.