White piedra, black piedra, tinea versicolor, and tinea nigra: contribution to the diagnosis of superficial mycosis.

Superficial mycoses are fungal infections restricted to the stratum corneum and to the hair shafts, with no penetration in the epidermis; they are: white piedra, black piedra, tinea versicolor, and tinea nigra. This study presents images of mycological tests performed in the laboratory, as well as exams performed at the authors office, in order to improve the dermatologist's knowledge about the diagnosis of these dermatoses, which are common in many countries.

White piedra, black piedra, tinea versicolor, and tinea nigra: contribution to the diagnosis of superficial mycosis

Abstract Superficial mycoses are fungal infections restricted to the stratum corneum and to the hair shafts, with no penetration in the epidermis; they are: white piedra, black piedra, tinea versicolor, and tinea nigra. This study presents images of mycological tests performed in the laboratory, as well as exams performed at the authors office, in order to improve the dermatologist's knowledge about the diagnosis of these dermatoses, which are common in many countries.

An Unusual Case of White Piedra Due to Trichosporon inkin Mimicking Trichobacteriosis.

White piedra is a superficial mycosis characterized by soft, white-to-tan, irregular nodules attached to the hair shafts. A 36-year-old man presented with small lumps in his pubic hair, without any other symptoms. The clinical features were suggestive of trichobacteriosis. Pathology analysis of the infected hair revealed that the concretions surrounding the hair shaft were full of fungal elements, parts of which had invaded into the cuticle. Culture on Sabouraud dextrose agar grew creamy, yellow-white colonies identified as Trichosporon inkin by the sequence of the nuclear ribosomal intergenic spacer region. The condition was treated by shaving the pubic hair and administering antifungal therapy (oral itraconazole and topical ketoconazole).

Tricomicosis axilar / Trichomycosis axillaris

No disponible

Trichosporon inkin: an uncommon agent of scalp white piedra. Report of four cases in Brazilian children.

We report four cases of scalp white piedra (SWP) in Brazilian female children. Morphological and physiological approaches gave inconsistent results for identifying Trichosporon to species level, while the sequencing of the intergenic spacer 1 region of ribosomal DNA accurately identified the agent of SWP as T. inkin. These cases emphasize the occurrence of this species causing this type of infection. The molecular identification of the suspected agent is needed for appropriate epidemiological surveillance of superficial mycoses caused by Trichosporon species.

Extensive white piedra of the scalp caused by Trichosporon inkin: A case report and review of literature.

Trichosporon species cause wide varieties of fungal infections. White piedra, a superficial fungal infection on the hair shaft, is caused by Trichosporon species. We report here a case of white piedra over the scalp due to T. inkin, a rarely isolated pathogen from such a lesion. The identification of the fungus was confirmed on the basis of morphology, carbohydrate assimilation tests, and sequencing of the ITS region of rDNA. The available literature on infections due to T. inkin is also reviewed.

Ultrastructural aspects of hair digestion in black piedra infection.

The ultrastructural pattern of human hair infection by Piedraia hortae in vivo has been studied. The fungus destroyed the cuticular layers of the hair and was able to penetrate deeply into the cortex. The course of destruction of human hair is described and compared with that produced by other fungi. Two well-defined types of cortex digestion were characterized. The slow rate of keratin degradation at the cortex together with the compacted stromatic organization of the nodules are argued as the main reasons that guarantee the long survival of the fungus, and therefore the chronic course of the disease. The data provided in this paper may help to understand the mechanisms that regulate the pathogenicity of this fungus.

X-ray microanalysis of black piedra.

The elements present in the fungal structures produced by Piedraia hortae in vivo and in vitro have been investigated using electron microscopy X-ray microanalysis. Phosphorus, sulphur and calcium were detected in the nodules which developed on hair and on colonies on culture. These elements belong to the extracellular material that compacts the pseudoparenchymatous organization of the fungus. They may be present due to the capacity of melanin-like pigments to sequester ions and/or they may form part of the sulphates and phosphates of the polyanionic mucopolysaccharides that constitute the extracellular material. Environmental contaminants such as aluminium, silicon and iron were detected exclusively on the surface of the nodule. They were deposited or linked to the residual molecules produced during the breakdown of the cuticular keratin. The advantages of these techniques for elucidating the chemical nature of fungal structures are discussed.

Ultrastructure of black piedra.

Black piedra or nodular trichomycosis is a superficial mycosis of the hair shaft, prevalent in the tropical areas of South America and Asia and caused by the fungus Piedraia hortai. By scanning electron microscopy the invasion of the hair keratin and the elimination of spores through canals was seen. Transmission electron microscopy showed a complex, well-organized microsystem, in which cement-producing hyphae constitute the pseudoparenchyma. Both sexual and asexual reproduction were found. Sexual reproduction gives rise to ascospores and asexual reproduction to arthrospores. The ascospores were found in thick-walled bags, the asci; the arthrospores, that undergo gemmation, are eliminated through canals, disseminating the disease.

Piedra branca: revisäo de literatura a respeito de três casos / White piedra: review of the literatura report of three cases

Os autores apresentam três casos de piedra branca comprometendo o couro cabeludo de crianças em idade pré-escolar. O Trichosporon beigelii foi caracterizado por exames micológicos. Revisa-se a literatura abordando aspectos clínicos, micológicos e terapêuticos

Cepholosporium acremonium. A new strain of fungus causing white piedra.

A strain of fungus (CZ408) was isolated from white piedra of a female child. Mycological identification showed that it is the first case in the world. Asymptomatic white nodules were noted on the hair of the scalp, and they were distributed irregularly along the shaft 4-10 cm from the scalp. The nodules, hard, not easily broken or removed, consist of hyphae, spores and metabolic materials around the hair. Oral antimycotic drugs are effective in treating this disease.

White piedra.

A 39-year-old Thai man had eczema on the left groin accompanied by asymptomatic white nodules on the public hair for two weeks. Examination with the Wood's lamp, microscopic examination, culture and biochemical testing showed organisms compatible with Trichosporon beigelii. The diagnosis of "White Piedra" was made, and this is the first case of White Piedra to be reported in Thailand.

[Clinical and mycological study of 11 cases of genitopubic trichosporosis nodosa (white piedra)]. / Etude clinique et mycologique concernant 11 cas de trichosporie noueuse (piedra blanche) génito-pubienne.

Piedra (stone in Spanish) is the name given to a trichomycosis characterized by the formation of nodules resembling small stones. There are two varieties of the disease, depending on the colour of the nodules: white piedra and black piedra. Black piedra sharply differs from white piedra on three main scores: a) the causative agent is a black filamentous and sexed dematicious fungus, Piedraia hortai; b) the disease exclusively affects the scalp, and c) the geographical distribution of human black piedra is limited to tropical and subtropical areas (South America, South-East Asia). White piedra has a different aetiology, being caused by an asexual fungus, Trichosporon beigeli. The genus Trichosporon (Behrend, 1890) and the species T. beigeli (Vuillemin, 1902) were created from a case of piedra of the moustache. White piedra may involve hairy regions other than the scalp, such as the beard and moustache, less frequently the armpits, eyebrows, eyelashes and pubic hair. The disease has been observed in all continents, except Africa, and under all climates, although it is exceptionally found in cold areas (two indigenous cases in Finland). The observatio princeps of white piedra (on a false chignon) was published in 1865 by Beigel, in London. In France, only three cases, all concerning the moustache, were reported at the very beginning of this century No other case has been published in that country in the east 80 years. T. beigeli is a common saprophyte in nature. It has been found in soil, water, fruit, rotten vegetables, sawdust, as well as in man (skin, skin appendages, mucosae) and in animals (mammals, insects, mussels).(ABSTRACT TRUNCATED AT 250 WORDS)

[Contribution to the study of Trichosporon cutaneum (de Beurman, Gougerot et Vaucher), Ota (1926) (author's transl)]. / Contribution à l'étude de Trichosporon cutaneum (de Beurman, Gougerot et Vaucher), Ota (1926). Partie II: Etude pathologique.

The pathogenicity is studied in vitro and in vivo. White piedra is obtained in vitro on hair applying a technic described by Vanbrueseghem (1949) for the study of dermatophytes. Concerning the in vivo study: retrocultures of the kidneys, the lungs, the brain and the liver of white mice inoculated with T. cutaneum (50,000 cells) by the intravenous route were all positive.