[Papular acantholytic dyskeratosis]. / Papulöse akantholytische Dyskeratose.

Papular acantholytic dyskeratosis is a very rare skin disease, which shows a suprabasilar cleft with acantholytic and dyskeratotic cells, simulating the light microscopic picture of Darier disease. In this condition, the lesions are acquired without a genetic basis. We observed a 40-year-old woman with about 200 papules on the lower aspects of her legs; histological examination showed changes similar to Darier disease. Transmission electron microscopy showed a reduced number of desmosomes and perinuclear distribution of tonofilaments. The lesions were successfully treated with cryotherapy with spray technique.

[Postinfectious Lucio phenomenon in diffuse leprosy. Report of 2 cases]. / Postinfektiöses Lucio-Phänomen bei diffuser Lepra. Bericht über zwei Fälle.

In the clinical classification of leprosy the diffuse nonnodular form belongs to the lepromatous subtype. In these patients only a diffuse cutaneous infiltration without nodules or plaques is seen. Although the cutaneous features can be difficult to identify, the reactional state in these cases may lead to a serious necrotizing vasculitis, known as Lucio's phenomenon. We describe two cases of Lucio's phenomenon triggered by erysipelas. The diagnosis of leprosy was established only after the immunologic reaction had occurred. Both patients were treated with steroids and thalidomide. In the second case, the bacterial infection led to sepsis and death. In at-risk patients with a necrotizing vasculitis, leprosy should be considered in the differential diagnosis.

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.

White piedra: ultrastructure and a new microecological aspect.

White piedra or trichosporosis is a superficial mycosis of the hair shaft, caused by the yeast Trichosporon beigelii; it has been found in all continents and may involve the hair of any part of the body. We report a case of white piedra on the hairs of the inguinal fold with ultrastructural studies. Transmission electron microscopy showed that the nodules have the same morphological aspects as the fungus in culture (hyphae and arthrospores) except for the presence of a cementant substance. By scanning electron microscopy the elimination of spores was seen on the nodule surface. Interestingly similar nodules were found on cotton fibres of the patient's underwear, which were also studied by scanning electron microscopy. This finding can explain therapeutic failure and demands special hygienic conditions related to clothes.