Clinton W. Lane

Comparative Studies of Histological Skin Changes Produced by X-Rays and by Lipoid Solvents

By varying the time period of exposure and transmitting the ray through an opening 1 cm. in diameter, we have produced various degrees of x-ray burns of the skin in a series of white rats. The quantity of x-rays used varied from 5 miliampere minutes to 50 miliampere minutes. Animals were placed on high vitamin A, low vitamin A, and balanced stock rations to determine if these dietaries would produce a difference in reaction to the x-rays. Our studies, thus far, have not shown any striking differences. The characteristic gross picture is depilation over the area of skin exposed, with the persistence of a roughened, scarred skin that appears from 14 to 21 days after the exposure to the x-rays. Five miliampere minutes and 10 miliampere minutes produce no effect grossly apparent. Microscopically the lesion is that of shrinking and edema of the epithelial layer, hyperplasia of the hair follicles, and in some cases a metaplasia of the basal layer of the skin. The subcutis shows varying degrees of hyalinization. With the high doses (50 miliampere minutes) there is a hyalinization of the subcutis and the glandular structures in it. The epithelium remains intact over the area, the higher dosages producing a pyknosis of the cell nuclei and a hyalinization of the cytoplasm. In the second series we applied a 50 per cent coal tar or pine tar preparation to a denuded area 2 cm. in diameter. The white rat was used. The tar was painted on the area with a cotton swab every 2 or 3 days. A roughening of the skin and a gradual loss of hair was noted grossly. Microscopically a hyperkeratosis begins at the 30th day, and gradually progresses.