Secondary abscesses must be aspirated or opened and drained whenever possible.

The general treatment is conducted on the same lines as on other forms of pyogenic infection.

CHAPTER V
ULCERATION AND ULCERS

The process of ulceration may be defined as the molecular or cellular death of tissue taking place on a free surface. It is essentially of the same nature as the process of suppuration, only that the purulent discharge, instead of collecting in a closed cavity and forming an abscess, at once escapes on the surface.

An ulcer is an open wound or sore in which there are present certain conditions tending to prevent it undergoing the natural process of repair. Of these, one of the most important is the presence of pathogenic bacteria, which by their action not only prevent healing, but so irritate and destroy the tissues as to lead to an actual increase in the size of the sore. Interference with the nutrition of a part by œdema or chronic venous congestion may impede healing; as may also induration of the surrounding area, by preventing the contraction which is such an important factor in repair. Defective innervation, such as occurs in injuries and diseases of the spinal cord, also plays an important part in delaying repair. In certain constitutional conditions, too—for example, Bright's disease, diabetes, or syphilis—the vitiated state of the tissues is an impediment to repair. Mechanical causes, such as unsuitable dressings or ill-fitting appliances, may also act in the same direction.

Clinical Examination of an Ulcer.—In examining any ulcer, we observe—(1) Its base or floor, noting the presence or absence of granulations, their disposition, size, colour, vascularity, and whether they are depressed or elevated in relation to the surrounding parts. (2) The discharge as to quantity, consistence, colour, composition, and odour. (3) The edges, noting particularly whether or not the marginal epithelium is attempting to grow over the surface; also their shape, regularity, thickness, and whether undermined or overlapping, everted or depressed. (4) The surrounding tissues, as to whether they are congested, œdematous, inflamed, indurated, or otherwise. (5) Whether or not there is pain or tenderness in the raw surface or its surroundings. (6) The part of the body on which it occurs, because certain ulcers have special seats of election—for example, the varicose ulcer in the lower third of the leg, the perforating ulcer on the sole of the foot, and so on.

The Healing Sore.—If a portion of skin be excised aseptically, and no attempt made to close the wound, the raw surface left is soon covered over with a layer of coagulated blood and lymph. In the course of a few days this is replaced by the growth of granulations, which are of uniform size, of a pinkish-red colour, and moist with a slight serous exudate containing a few dead leucocytes. They grow until they reach the level of the surrounding skin, and so fill the gap with a fine velvety mass of granulation tissue. At the edges, the young epithelium may be seen spreading in over the granulations as a fine bluish-white pellicle, which gradually covers the sore, becoming paler in colour as it thickens, and eventually forming the smooth, non-vascular covering of the cicatrix. There is no pain, and the surrounding parts are healthy.

This may be used as a type with which to compare the ulcers seen at the bedside, so that we may determine how far, and in what particulars, these differ from the type; and that we may in addition recognise the conditions that have to be counteracted before the characters of the typical healing sore are assumed.

For purposes of contrast we may indicate the characters of an open sore in which bacterial infection with pathogenic bacteria has taken place. The layer of coagulated blood and lymph becomes liquefied and is thrown off, and instead of granulations being formed, the tissues exposed on the floor of the ulcer are destroyed by the bacterial toxins, with the formation of minute sloughs and a quantity of pus.