1911 Encyclopædia Britannica/Abscess
ABSCESS (from Lat. abscedere, to separate), in pathology, a collection of pus among the tissues of the body, the result of bacterial inflammation. Without the presence of septic organisms abscess does not occur. At any rate, every acute abscess contains septic germs, and these may have reached the inflamed area by direct infection, or may have been carried thither by the blood-stream. Previous to the formation of abscess something has occurred to lower the vitality of the affected tissue—some gross injury, perchance, or it may be that the power of resistance against bacillary invasion was lowered by reason of constitutional weakness. As the result, then, of lowered vitality, a certain area becomes congested and effusion takes place into the tissues. This effusion coagulates and a hard, brawny mass is formed which softens towards the centre. If nothing is done the softened area increases in size, the skin over it becomes thinned, loses its vitality (mortifies) and a small "slough" is formed. When the slough gives way the pus escapes and, tension being relieved, pain ceases. A local necrosis or death of tissue takes place at that part of the inflammatory swelling farthest from the healthy circulation. When the attack of septic inflammation is very acute, death of the tissue occurs en masse, as in the core of a boil or carbuncle. Sometimes, however, no such mass of dead tissue is to be observed, and all that escapes when the skin is lanced or gives way is the creamy pus. In the latter case the tissue has broken down in a molecular form. After the escape of the core or slough along with a certain amount of pus, a space, the abscess-cavity, is left, the walls of which are lined with new vascular tissue which has itself escaped destruction. This lowly organized material is called granulation tissue, and exactly resembles the growth which covers the floor of an ulcer. These granulations eventually fill the contracting cavity and obliterate it by forming interstitial scar-tissue. This is called healing by second intention. Pus may accumulate in a normal cavity, such as a joint or bursa, or in the cranial, thoracic or abdominal cavity. In all these situations, if the diagnosis is clear, the principle of treatment is evacuation and drainage. When evacuating an abscess it is often advisable to scrape away the lining of unhealthy granulations and to wash out the cavity with an antiseptic lotion. If the after-drainage of the cavity is thorough the formation of pus ceases and the watery discharge from the abscess wall subsides. As the cavity contracts the discharge becomes less, until at last the drainage tube can be removed and the external wound allowed to heal. The large collections of pus which form in connexion with disease of the spinal column in the cervical, dorsal and lumbar regions are now treated by free evacuation of the tuberculous pus, with careful antiseptic measures. The opening should be in as dependent a position as possible in order that the drainage may be thorough. If tension recurs after opening has been made, as by the blocking of the tube, or by its imperfect position, or by its being too short, there is likely to be a fresh formation of pus, and without delay the whole procedure must be gone through again.