Persistent lenticular keratosis: causes, symptoms, diagnosis, treatment
Last reviewed: 23.04.2024
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Keratosis resistant lenticular (blue Phlegel's disease) belongs to the group of hereditary diseases with a predominant infringement of keratinization, the type of inheritance is autosomal dominant. Men and women often suffer equally. The first manifestations of the disease are observed at the age of 40-50 years in the form of reddish-brown small papules 1-4 mm in size, covered with scales, irregular contour, localized on the rear of the feet, upper and lower extremities. When removing scales, a shiny bottom of the funnel with pinpoint bleeding is exposed. Rashes sometimes are accompanied by a slight itch. It is combined with diabetes mellitus.
Pathomorphology. In the center of the lesion, thinning of the epidermis is noted, along the edges - acanthosis and papillomatosis. The stratum corneum is mostly compact, considerably thickened, especially in the center of the element, where also focal parakeratosis is detected. The granular layer is absent in the atrophic parts of the epidermis. Basal epithelial cells are flattened, edematous, the epidermis basal membrane is indistinct. In the papillary layer and the upper part of the mesh layer of the dermis, the vessels are enlarged, a dense infiltrate of lympho-histiocytic character is clearly delineated from the underlying dermal layers. In horny scales, electron-microscopic examination of the skin in the atrophy zone reveals bright threads in a dense matrix, the preservation of desmosomes. Parakeratotic cells are detected, and the amount of keratogialin granules decreases. In granular epithelial cells and the absence of lamellar granules in them. In the infiltrate, lymphocytes with cerebriform nuclei were found.
Histogenesis. Great importance is attached to the pathology of lamellar granules, which play an important role in the differentiation of epithelial cells. However, unambiguous data on their changes have not yet been received. Based on the detection in the infiltrate of cells of macrophage lime and lymphocytes with cerebral nuclei, the role of immune reactions in the development of the disease is assumed.
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