A practical treatise on diseases of the skin / by Henry G. Piffard ...assisted by Robert M. Fuller.

  • Piffard, Henry G. (Henry Granger), 1842-1910.
Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: A practical treatise on diseases of the skin / by Henry G. Piffard ...assisted by Robert M. Fuller. 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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    change in its thickness or consistence. The macule itself may be white from loss of pigment, red from congestion, or dark or black from increase of pigment. A vesicle is a small elevation of the horny layer of the epidermis, by the effusion of a serous fluid. A bulla is a larger elevation of the epidermis by a serous or sero-fibrinous effusion. A pustule is an elevation of the epidermis, small or large, by a purulent exudation. The common feature of these three lesions is a fluid exudation—serous, sero- fibrinous, or purulent—which lifts up a greater or less extent of horny epidermis, producing an elevation on the skin, and the lesion consists of an effused fluid, kept in bounds by a limiting membrane. A vesicle, bulla, or pustule having formed, may further progress in one of several ways. After a few days the effusion may be reabsorbed without rupture of the epidermis, and leave nothing but a loosely attached scale, which soon exfoli- ates. On the other hand, the epidermis may rupture in a day or two, the effusion be poured out, and the whole dry up to a small crust, which in a few days more is wholly detached; or, still again, a vesicle or pustule may rupture promptly, but from the denuded surface a serous or purulent fluid may continue to exude for several days or even weeks. A papule is a small, solid elevation of the skin. In this case the exudation into the skin is of a plastic character, mostly cells with but little fluid effusion— not sufficient, in fact, to produce a vesicle. A papule may disappear in a few days by absorption of the exudation, or may be gradually converted into a pustule ; or may undergo ulceration, or may even persist without alteration almost indefinitely. A tubercle is a solid elevation of the skin, larger than a papule, but agree- ing with it in other respects, and capable of undergoing the same changes— namely, absorption, pustulation, ulceration, or indefinite prolongation. Scales are collections of cells of the stratum corneum, which, instead of pur- suing their usual and normal course, collect in undue number and quantity, and are loosely or firmly attached to the skin in more or less heaped-up masses. When these scales are small in size, loosely attached, like a fine powder or meal scattered over the surface, they are termed farinaceous; on the other