CHAPTER IV
.
ULCER AND ULCERATION.
The term _ulcer_ pertains to surfaces, and should be defined as a _surface which is or ought to be granulating_, _i. e._, _healing_.
While an ulcer may be the result of ulceration, it is not necessarily so, the term _ulceration_ being one of very loose significance and applied to many different processes. The idea underlying ulceration is _infection_, and, when limited to its proper significance, the term should never be used for a process in which infection and consequent breaking down of tissue do not virtually comprise the whole process. Therefore, it is to be distinguished from certain disappearances of tissue alluded to under the head of Atrophy or Interstitial Absorption. It is not correct to say that the sternum ulcerates away, making room for a growing aortic aneurysm, the question of infection here not being raised. These distinctions should be accurately maintained and constantly borne in mind.
ULCERS.
The causes of ulcers may be--
A. _Traumatic_;
B. _Local_; or,
C. _Constitutional_.
A. =Traumatic.=--This includes all surfaces which are granulating and healing more or less rapidly, or are displaying a disposition toward healing, and which may have been produced by _wounds_, _burns_, _frostbites_, etc. These include also ulcers due to _pressure_, as from splints, bandages, orthopedic apparatus, or from _external friction_. Ulcers which form around _foreign bodies_ may also be included under this head, their essential cause being traumatic. It should include also destruction of the surface by various _chemical agencies_, such as strong caustics, and the consequences of intense _heat_ or _cold_, including burns and frostbites.
B. =Local.=--1. Among local causes may be mentioned _local infections_, with tissue death in consequence, such as occur in tuberculous, cancerous, leprous, syphilitic, and other specific manifestations where surfaces are involved.
2. _Tumors_, either benign or malignant, whose blood supply is cut off and whose surface is thereby predisposed to infection.
3. _Perverted surface nutrition_, for example, in connection with varicose veins of the extremities, where, aside from any perverted trophoneurotic influence, there is stagnation of blood, saturation of tissues with serum, and final leakage of the same, even to the surface. Varicose veins of the leg which lie near or underlie ulcerating surfaces become thrombosed and obliterated, so that such ulcers rarely bleed. On the other hand, a passive hyperemia here leads to edema, perversion of nutrition, failure to repair trifling surface injury, and a surface is left which of itself rarely, if ever, heals.
4. So-called _pressure sores_ or _bed-sores_, which in some cases may be regarded as having a traumatic origin, but which, nevertheless, would not occur from purely traumatic influences without predisposing tissue changes. The bed-sore is probably the best illustration of this. Simple ulcer is known as bed-sore, while a sloughing ulcer of this kind is frequently alluded to as _decubitus_. Such ulcers are usually found over those regions of the body made most prominent by bony projections, upon which undue pressure is made when debilitated patients have lain for a long time in bed.
5. Ulcer is the frequent result of numerous _skin diseases_, into whose etiology as yet bacteria have not been introduced--_e. g._, pemphigus, eczema, etc.
6. Ulcer is the occasional result of _embolic_ or other _disturbance_ of the principal artery of the part, by which nutrition is cut off and tissue death results.
7. _Bites of insects_ or other _parasites_ or of noxious animals frequently lead to ulceration.
8. Certain more specific forms of ulcer are described by some writers, apparently with more or less reason, among them being _chancroid_, _perforating ulcer of the foot_, etc. (Chancroid is described in
##