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Follicular and parafollicular hyperkeratosis penetrating into the dermis: causes, symptoms, diagnosis, treatment
Last reviewed: 23.04.2024
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Hyperkeratosis follicular and parafollicular, penetrating the dermis (syn: Kirl's disease) is a rare disease with an unidentified type of inheritance, clinically manifested by keratotic papules ranging in size from 3-4 mm to 1 cm, rarely more localized mainly on the extensor surfaces of the extremities. At the center of each element is a conical hyperkeratotic plug. The tendency towards the follicular (in the zone of funnels of the hair follicles) is characteristic. Papules can merge with the formation of polycyclic or linear, often verrux foci.
The cases of the development of the disease in the course of long-term treatment with D-penicillamine in patients with diabetes mellitus and renal insufficiency are described.
Pathomorphy. In the depressions of the epidermis, and sometimes in the expanded estuaries of the hair follicles, large hyperkeratotic plugs are found. In the zone of the horn cork there are parakeratotic cells and basophilic stained with hematoxylin and eosin cellular detritus. Under the horn corks, a granular layer is well developed, with the exception of parakeratosis. In places where there is no granular layer in fresh elements, foci of vacuolized discrete cells are observed. In older elements, the epidermis is atrophic, the keratotic masses penetrate the dermis, where a granulomatous reaction occurs with giant cells of foreign bodies. Collagen fibers with dystrophy phenomena, the number of elastic fibers increased.
Histogenesis. The presence of disceratotic and parakeratotic cells indicates a violation of the keratinization process, which is manifested in the rapid premature cell anatomy, which can begin already in the lower rows of the prickly layer and involve the basal layer in the process.
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