abscess. A circumscribed cavity containing pus.

Chronic Abscess  is a term referring only to time. Usually a tubercular abscess is designated as a chronic, cold, or scrofulous abscess. It is an area of disease produced by the action of the tubercular bacilli and is circumscribed by a distinct membrane. The symptoms present no inflammatory signs. Constitutional symptoms are trivial or absent unless secondary infection occurs. The treatment of these cold abscesses depends upon their location.

A Furuncle or Boil  is an acute and circumscribed inflammation of the deep layer of the skin and the subcutaneous cellular tissue, following on bacterial infection of the hair follicle through a slight wound (by scratching, shaving), with the staphylococcus pyogenes aureus.

Symptoms. The symptoms of a boil are as follows: a red elevation appears, which stings and itches; this elevation enlarges and becomes dusky in color, a pustule forms that ruptures and gives out a very little discharge which forms a crust; inflammatory infiltration of adjacent connective tissue advances rapidly, and the boil in about three days consists of a large red, tender, and painful base, capped by a pustule and some crusted discharge. In rare instances, at this stage, absorption occurs, but in most cases the swelling increases, the discoloration becomes dusky, the skin becomes edematous, the pain severe, and the centre of the boil becomes raised. About the seventh day rupture occurs, pus runs out, and a core of necrosed tissue is found in the centre of a ragged opening. The hair follicle and the sebaceous gland, which have undergone necrosis, are found in this core. Healing by granulation will occur; the constitution often shows reaction during the progress of a boil.

Boils may be either single or multiple, and the development of one boil after another, or the formation of several boils at once, is known as furunculosis.

Treatment. The treatment consists of crucial incision and the application of a wet dressing.

Acute Abscesses. An abscess may be defined as a circumscribed cavity of new formation, containing pus. An essential part of this definition is the assertion that the pus is in a cavity of new formation; is an abnormal cavity; hence pus in a natural cavity (pleural or synovial) constitutes a purulent effusion, and not an abscess, unless it is encysted in these localities by walls formed of inflammatory tissue.

An acute abscess is due to the deposition and multiplication of pyogenic bacteria in the tissues or in inflammatory exudates.

When abscesses form in an internal organ or in some structure which is not loose like connective tissue, for instance, in a lymphatic gland, a mass of pyogenic bacteria floating in the blood or lymph, lodges, and these bacteria, by means of irritant products, cause coagulation necrosis of the adjacent tissue and inflammatory exudation around it. The area of coagulation necrosis becomes filled with white blood cells, and the dry necrosed part is liquefied by the cocci. Suppuration in dense structures causes considerable masses of tissue to die and to be cast off, and these masses float in the pus.

An abscess heals by the collapse of its walls, and the formation of an abundance of granulation tissue; in many cases granulations of one wall join those of the other side, the entire mass of granulations being converted into fibrous tissue, and this tissue contracting, heals by third intention. If the walls do not collapse, the abscess heals by second intention.

Symptoms. The symptoms of an acute abscess may be divided into (1) local, (2) constitutional. Locally there is intensification of inflammatory signs; swelling enormously increases; the discoloration becomes dusky; the pain becomes throbbing, and the sense of tension increases; the cutaneous surface is seen to be polished and edematous, and after a time, pointing is observed and fluctuation can be detected. The constitutional symptoms are usually limited to chills and fever, depending upon the severity of the infection.

Treatment  is free incision and drainage. The wound should be opened early, if possible even before pointing or fluctuation, to prevent destruction, subfascial burrowing, and general contamination; drainage is continued until the discharge becomes scanty, thin and seropurulent.