Selected monographs on dermatology / P.G. Unna [and others].

Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: Selected monographs on dermatology / P.G. Unna [and others]. Source: Wellcome Collection.

    35/636 (page 21)
    sensations and by fever, and is liable to be confounded with scarlatina. The internal administration of salicylic acid, carbolic acid, stramonium, veratrine, and digitalis causes general hyperemia of the skin. And these rashes are not brought about by a vaso-neurosis alone; the toxic material injures the vessel walls, and thereby causes the symptoms of a slight cutaneous inflammation. A third group is represented by the antipyrin rash ; this drug gives rise to discrete, raised, somewhat oedematous, itching papules, which are not unlike the rash of measles. It affects chiefly the neighbourhood of joints, seldom the trunk, and less seldom the face, neck, and genital organs. The subjective symptoms are more pronounced, desquama- tion less so, than in the erythemata of the second group. To this group belong the morphia, cubebs, and copaiba rashes, and those resulting from the administration of tur- pentine, hyoscyamus, and chlorate of potash. We now turn to the relaxive hyperasmias that have a more local character, and we may divide them into three groups. 1. The first group includes those erythemata in which the paresis of the muscular coat of the arteries is called forth by physical causes. We must mention first of all the hyperemia which results from the cessation of any pressure upon the skin, such as is seen after the application of an Esmarch's bandage, or in the red lines left on the skin by drawing one's finger-nail across it. The author looks upon this as a pressure paralysis of the individual capillaries and arterioles—as an idio-paresis, and not a paresis brought about by the intervention of the vaso- motor centres. 2. Hypereemia caused by variations in temperature is seen in newly born children. Cold has a paralysing effect upon the vessels only when they have been exposed to its influence for some time. The reactionary paralysis brought about by low temperatures lasts only as long as the application of the cold continues. 3. The paralysis of the vessels caused by heat must be differently explained. Warming the skin does not directly paralyse the vessels ; it causes a more rapid and consequently