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.

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    characteristics common to them as a class may be referred to in this connection. While it is not possible to formulate with absolute pre- cision the distinctive characters of drug eruptions, or indicate definite features by which they may in every instance be recognised, and at once differentiated from the idiopathic affections of the skin, yet they possess certain special attri- butes which stamp them as a separate clinical class. The polymorphism of drug eruptions constitutes a dis- tinctive feature. Every possible lesion of the skin—macules, papules, wheals, tubercles, vesicles, bullae, pustules, furuncles, ulcerations, gangrene, &c.—has been observed as the direct result of the use of drugs. The rapidity with which the eruption develops.—Eruptions provoked by external irritants usually make their appear- ance within a few hours after the application of the exciting cause. The intensity of the resulting dermatitis depends upon the nature and strength of the irritant, the duration of its contact, and the sensitiveness of the skin. The differ- ence in the susceptibility of the skin of different individuals to external irritants is markedly shown in relation to arnica, poison ivy, &c. The length of time which intervenes between the inges- tion of drugs and the first appearance of the eruption also varies according to the nature of the drug, the quantity administered, and the predisposition of the individual. In general it may be said that certain forms, especially the erythematous and exudative, come out rapidly, from a few minutes to several hours after the ingestion of the drug, and vanish with the same celerity with which they appeared, if the offending agent be withdrawn. In other cases it may require repeated and long-continued use to develop the irritating effect upon the skin. In still another class of cases, small doses—smaller, indeed, than are re- quired to produce the ordinary physiological effect of the drug—promptly determine violent tegumentary disturbance. It is noteworthy that, in exceptional cases, large doses of the same drug in the same individual may occasion no such effect. In these cases there would seem to be a reversal of the material law that increase of quantity carries with it
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