- Porokeratosis reasons
- Porokeratosis symptoms
- Treatment of a porokeratosis
Porokeratosis - the disease inherited autosomal is prepotent. It is described several clinical options of a porokeratosis differing on group, quantity and localization of vysypny elements: Mibelli's porokeratosis which is characterized by single elements. located preferential on extremities: the superficial disseminated eruptive porokeratosis of Resshigi differing in the multiple centers of defeat developing at children's age; linear, neviformny (or zosteriformny) the porokeratosis which is found usually on extremities and reminding a linear verrukozny nevus; the disseminated superficial actinic porokeratosis which is appearing more often at adults after solar radiation and localized on open body parts; the dot porokeratosis which is characterized by diffusion rashes on fingers, palms and soles; the palmar and bottom and disseminated porokeratosis in the form of numerous rashes in the beginning on palms and soles, then on a trunk and extremities. Three more options - a discrete porokeratosis of soles with the single or multiple conic papules reminding bottom warts, a mesh porokeratosis with the erythematic rashes in the form of a grid which are localized on a trunk and the disseminated bilateral giperkeratotichesky option of a porokeratosis of Mibelli are described.
The porokeratosis is the hereditary disease which is transmitted autosomal is prepotent with a reduced penenrantnost. A condition of an immunosuppression, immune супрессивные diseases, in particular AIDS, ultra-violet radiation can cause or aggravate a porokeratosis. In the centers of defeat the dysplasia of various degree of manifestation, formation of pathological clones of cells which are more sensitive to ultra-violet radiation, than surrounding gratuitous cells are revealed. In the cultivated fibroblasts instability 3 chromosomes is found that increases risk of development of a skin neoplasia. In literature there is a description of family cases.
Distinguish several clinical kinds of a porokeratosis.
Clinically the same morphological element - ring-shaped plaques of various sizes with the sinking-down atrofichny center and the raised giperkeratotichesky narrow edge with a groove on a surface is characteristic of all options of a porokeratosis. Development of such element begins with formation of the keratotichesky papule which is gradually increasing in sizes, creating a ring-shaped plaque after which regressing there is a site of an atrophy of skin. The elements localized on palms and soles differ by the form a little. So, at a dot porokeratosis they represent the small deepenings with a diameter of 1-3 mm filled with a keratin at a discrete bottom porokeratosis - the conic papules reminding bottom warts. Sometimes atypical rashes - giperkeratotichesky, verrukozny, ulcerating, exudative and huge meet. The possibility of a combination of different clinical options of a porokeratosis at the same patient confirms общносгь them a pathogeny.
Combinations of a porokeratosis and psoriasis are described. Cases of developing of malignant tumors like planocellular cancer, a bazalioma and Bowen's disease at patients with a porokeratosis are frequent that gives the chance to some authors malignant growth begins to consider it a precancerous disease at the same time usually in the field of the atrofichny center of ring-shaped plaques.
Classical porokeratosis of Mibeli. The disease meets at children more often, but can develop at any age. An initial element is the horn papule which due to excentric growth increases in a size and turns into a ring-shaped plaque. Rashes are usually not numerous, plaques of various sizes - from several millimeters to several centimeters, rounded shape. The central part of an element looks sunk down, dry, slightly atrofichny, sometimes - or hyper pigmented, warty or with the hyperkeratosis phenomena. In a peripheral zone of the center of defeat the raised keratotichesky roller (border) is swept well up. At attentive survey by means of a magnifying glass on a surface of a border it is possible to see a characteristic sign - parallel and parno the located ranks of a hyperkeratosis.
The defeat centers are located on a body, hands, legs more often. Genitals, a mucous membrane of an oral cavity and a cornea can be surprised.
The disseminated superficial actinic porokeratosis meets in the third or fourth decade of life on the sites of skin which are treated to action of sunshine more often. Usually the defeat centers multiple and on a clinical picture remind a classical porokeratosis of Mibeli. However at an actinic porokeratosis on a border surface parallel, pair ranks of a hyperkeratosis are not found more often.
The palmar and bottom and disseminated porokeratosis - a rare form a porokeratosis and meets at adults more often. The disease begins with emergence on palms and soles numerous small, slightly towering, papules or plaques. Then the centers extend to other body parts. At this kind of a porokeratosis predisposition of the centers of defeat to be localized on the body parts which are exposed to a sunlight it is not noted. However at 25% of patients the exacerbation of a disease is observed during the summer period.
The linear porokeratosis usually begins at children's age. There are multiple papules of rounded shape located unilateralno, linearly, segmentarno or zosteriformno on a trunk or extremities, is frequent in the area of Blashko. On a clinical picture the linear porokeratosis very much reminds an epidermal nevus. Erosive and ulcer options of a current of a linear porokeratosis on a face are described.
Current of a porokeratosis. The disease exists for many years, but cases of spontaneous permission are described. At all options of a clinical current skin process can be transformed to neoplastic.
Histopathology. In the central part of an element keratin invagination in epidermis in the form of a cone, sometimes fascinating all its thickness is observed. In the center of invagination in horn masses the parakeratotichesky column (plate) - a characteristic symptom of a disease is visible. Under a column the granular layer is absent, but, generally, this layer is thinned. In a derma - vasodilatation, perivascular limfogistotsitarny infiltrates.
Treatment of a porokeratosis:
Appoint keratolytic means, a cryolysis, intra focal introduction of corticosteroids, 5% ointment of a 5-flyuoratsil; at an actinic form - photoprotective creams; at common forms aromatic retinoids or high doses of vitamin A are recommended.