ABSCESS. — Lat., abscesses, from ab scedere, to depart.
Definition.—A collection of pus in an adventitious cavity, the result of an acute, circumscribed inflammation due to infection with pus-forming microbes. Varieties.—An abscess may be acute, or warm, when due to pus-microbes only: staphylococci, streptococci, and others; chronic, or cold, when due to a specific microbe, especially that of tuberculosis.
Abscesses have been classified accord ing to:— 1. Etiology.—Atheromatoths, embolic, Neal (stercoraceons), lymphatic, meta static, miliary, ossifluent, puerperal, pre mic; residual symptomatic, or congest ive; tropical, tubercular (strumous, or scrofulous), etc.
2. Palhology.—Acute, or warm; cana licular; caseous; chronic, or cold; critical, diffuse, gangrenous (anthrax), ligneous, perforating, phlegmonous, etc.
3. Location (Organ or Tissue In volved).—Alveolar (gum, jaw, teeth), of antrum, of axilla, bone (subperiosteal), brain (cerebral, cerebellar), bursal, cor neal (hypopyon), deep, dorsal, follicular, hepatic, of hip-joint, iliac, ischio-rectal, lacunar, lumbar, mammary (milk; weid, or weed; breast), marginal, mediastinal, meningeal (extradural, subdural), of middle ear, of neck, nephritic and perinephritic, of nose, of palate, palmar, of pancreas, pectoral (empyema), peri typhlitic, popliteal, of prostate, psoas, rectal, retropharyngeal, of skin (furun culosis), of scalp, of space of Retzius (properitoneal cavity); spinal, or verte bral; of spleen, superficial, thecal, ure thral and peritirethal, vulvo-vaginal (Bartholinian). etc. All the above varieties will be considered under their respective anatomical heads.
Acute, or Warm.
Symptoms.—An abscess may either be superficial or deep. When it is super ficial 1 he local symptoms predominate; when it is deep the general symptoms are generally the most marked.
The pain, due to compression of the nerves by the disturbed tissues, varies in degree with the density of the parts involved, the local supply of sensitive nerves, and the tension produced by the inflammatory products. In superficial abscess the pain is generally localized in the centre of the swelling, and is sharp and lancinating; in deep abscess it is more diffuse and dull.
Redness is due to engorgement of the local blood-supply, and the swelling to the inordinate distension of the ves sels and the secondary escape of blood plasma, colorless corpuscles, etc., into surrounding tissues. It may become very great in regions such as the lids, the lips, etc., in which the cellular tissue is lax. As the purulent foci run together and form a single cavity, the centre of the tumefaction becomes soft, and darker in color, and the abscess is said to be "pointing." (Edematous infiltration in superficial abscess denotes the presence of pus; in deep abscess subcellular oedematous in filtration is an important sign of deep suppuration.
Local heat, throbbing, and tension are mechanical results of the causes of tu mefaction tending to decrease as the formation of pus progresses.
Hyperpyrexia is in relation with the location of the abscess, the ease with which the pus-microbes can enter the circulation, and the amount of pus and necrotic tissues present. In superficial abscess there is but little rise of tempera ture, but in deep abscesses it sometimes reaches 104° F. (40° C.) at the time the wall of granulation tissue is established. A remission of about one degree each morning usually takes place. When the pus has found an issue, or has become completely surrounded by the limiting membrane, the intensity of the fever is usually reduced.
In a superficial abscess, if a chill oc cur, it is usually very slight, and appears between the fourth and the eighth day. It indicates the formation of pus. In a deep abscess a chill generally occurs, last ing from a few moments to half an hour.
Fluctuation is generally obtained when the purulent focus has been formed. A sharp localized pain, on pressure over the apex of the swelling, obtained at this time supports the likelihood that pus is present, but fluctuation is liable to be a misleading symptom.