Selected monographs on dermatology / Unna, Nielsen, Duhring, Bronson, Blanc, Berger, Prince-Morrow.

  • New Sydenham Society.
Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: Selected monographs on dermatology / Unna, Nielsen, Duhring, Bronson, Blanc, Berger, Prince-Morrow. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    enough to explain the petechia. It is more likely that the fibrinous clots, also found by him, in the capillaries and arteries were the primary cause. The continuous blocking of whole capillary areas, due partly to changes in the vas- cular walls and partly to a continuous formation of thrombi, goes much further towards explaining the infective cutane- ous haemorrhages. Amyloid capillary degeneration, with cutaneous haemor- rhage, was found by Wilson Fox in a case of syphilis; but this is exceptional. Hyaline degeneration is often found in chronic dermatoses, but never amyloid. Askoro described considerable endothelial thickening in specimens from a scor- butic gum ; and Leloir observed a peculiar proliferation of endothelium, and its partial detachment in cutaneous haemor- rhages, which occurred shortly before death in a case of cirrhosis of the liver with interstitial nephritis and athe- roma of the aorta. The vessels were dilated, especially in the papillae, and there was vigorous emigration of leucocytes ; but no fibrin plugs were formed. He attributed the oblite- ration of the capillaries, partly to a stagnation of white discs, and partly to the desquamating endothelium. Hayem has similarly attributed cutaneous haemorrhages, in a case of phthisis and peliosis rheumatica, to endarteritis obliterans. It is not likely, however, that this process, which occurs so- commonly in the skin without producing anything of the kind, should by itself cause haemorrhage. Endophlebitis obliterans, on the other hand, might cause stagnation dia- pedesis, &c, but it is not known to occur. The plugging of the arteries with finely granular matter, also observed by Hayem, is of more importance. Endarteritis can only assist by lowering the pressure and velocity of the blood-stream. In purpura haemorrhagica Letzreich found bacilli and spores imbedded in gelatinous plugs, produced, he thought, by the action of the organisms on the serum albumin, and completely filling the capillaries. It is likely that in Hayem's cases, and in many other forms of purpura, a similar process of bacterial emboli is in question, with clotting of plasma along extensive tracts, consecutive stagnation and diapedesis. Klebs was the first to connect cutaneous haemorrhages with bacteria. He found colonies of his monas haemorrhagi-