From Big Medical Encyclopedia

POROKERATOSIS [porokeratosis; grech, poros the opening, pass, is time + a keratosis (y); synonym: Mibelli's porokeratosis, hyperkeratosis eccentric Respighi, hyperelastosis eccentric atrophic] — the hereditary keratosis which is characterized by preferential disturbance of keratinization of epidermis in a zone of output channels of sweat glands. In detail described a disease in 1893 Mr. of V. Mibelli.

The etiology and a pathogeny

the Aetiology and a pathogeny are not established. The item is inherited on autosomal dominantly type (assume that inheritance can be linked to a floor). Some researchers consider that P. is connected with proliferation of a mutant clone of cells of the epidermis which is formed under in oz actions iy U F - about l of the doctrine.

At the disseminated superficial actinic porokeratosis of Chernoski (M. of E. Chernosky, 1966) and other researchers revealed close interrelation a wedge, manifestations with insolation and a role of UF-radiation in genesis of this dermatosis.

At patogistol, a research note a hyperkeratosis like a horn stopper, in the central part a cut parakeratotichesky cells at located in a deep fillet in epidermis are visible, the granular layer to the floor to a zone is absent, acanthceous — at-rofichen; in a derma under the roller consisting of horn cells inflammatory infiltrate from lymphocytes and histiocytes is observed; in a papillary layer — fibrosis.

Distinguish actually V. Mibelli's porokeratosis (typical option) and the disseminated superficial actinic porokeratosis. At V. Mibelli's porokeratosis the wedge, manifestations arise at children's age. As a rule, on a dorsum of brushes (it is frequent on one) there are horn miliary papules which are gradually turning: in small plaques of grayish-brown or copper-colored color of the wrong outlines, the center to-rykh atrofichen and slightly sinks down. On edge of plaques the brownish roller from horn cells like a comb remains. The disease slowly progresses, the centers of defeat extend on skin of extremities, necks, trunks are more rare. Some of them can have the linear form. Also damages of visible mucous membranes, corneas, dystrophy of nails, anomalies of development of teeth, mental retardation are possible.

The disseminated superficial actinic P. develops more often after 30 years. The centers of defeat are usually localized on the open sites of skin available to insolation — on extensor surfaces of forearms, shins, and also on a dorsum of brushes, on a face. At the same time miliary horn papules gradually form small plaques to dia. 0,5 — 1,0 cm with uneven or wrong and oval outlines, with accurate slightly raised edge and usually atrophied center of brownish or pinkish color. Some horn papules have the central impression. Gradually the quantity of the centers of defeat increases, especially in summertime of year. Course of a disease chronic.

The diagnosis, Treatment, the Forecast, Prevention

P.'s Diagnosis establish on the basis a wedge, pictures and results gistol, researches of skin. Items differentiate with a disease to Darya (see. to Darya disease ), a White's serpiginoziy disease (see. Keratoza ), Kirle's disease (see. Kirle disease ) and other keratoza.

P.'s treatment is carried out by Aevitum, vitamins A and by groups B; outwardly apply ointments with the softening and keratolytic action; electrothermic coagulation, cryotherapy and cauterizations is recommended by liquid nitrogen of the separate centers; at the disseminated superficial actinic P. — photoprotective ointments.

Forecast favorable. However development of a carcinoma in the field of the centers of a porokeratosis of Mibelli is possible.

P.'s prevention is not developed. For prevention of aggravations of the disseminated superficial actinic P. it is necessary to avoid solar radiation.

Bibliography: Hereditary diseases, under the editorship of L. O. Badalyan, Tashkent, 1980; Piltiyenko L. F. To a question of Mibelli's porokeratosis, in book: Aktualn, vopr. dermas, and veins., under the editorship of O. P. Komov, etc., page 85, Minsk, 1972; P about t about the Central Committee y I. I. Giperkeratoza, Kiev, 1977; With h e r n about s k at M. of E. Disseminated superficial actinic porokeratosis, Int. J. Derm., y. 12, p. 152,1973; Mibelli V. Contributo alio studio della ipercheratosi dei canali sudoriferi (porokeratosis), G. ital. Mai. vener., v. 28, p. 313, 1893; N i-colau R. Lungu G. Porokera-toza Mibelli, Derm. - Vener. (Buc.), v. 17, p. 69, 1972; P i r o z z i D. J. a. Rosenthal A. Disseminated superficial actinic porokeratosis, Brit. J. Derm., v. 95, p. 429, 1976; Raff M. u. Sant-1 e r R. Porokeratosis Mibelli in linearer Anordnung, Z. Haut-u. Geschl. - Kr., Bd 47, 5. 27, 1972.

S. S. Kryazheva.