A third group of chronic inflammations are those that begin as an acute pyogenic inflammation, which, instead of resolving completely, persists in a chronic form.  It does so apparently because there is some factor aiding the organisms and handicapping the tissues, such as the presence of a foreign body, a piece of glass or metal, or a piece of dead bone; in these circumstances the inflammation persists in a chronic form, attended with the formation of fibrous tissue, and, in the case of bone, with the formation of new bone in excess.  It will be evident that in this group, chronic inflammation and repair are practically interchangeable terms.

There are other groups of chronic inflammation, the origin of which continues to be the subject of controversy.  Reference is here made to the chronic inflammations of the synovial membrane of joints, of tendon sheaths and of bursae—­chronic synovitis, teno-synovitis and bursitis; of the fibrous tissues of joints—­chronic forms of arthritis; of the blood vessels—­chronic forms of endarteritis and of phlebitis and of the peripheral nerves—­neuritis.  Also in the breast and in the prostate, with the waning of sexual life there may occur a formation of fibrous tissue—­chronic interstitial mastitis, chronic prostatitis, having analogies with the chronic interstitial inflammations of internal organs like the kidney—­chronic interstitial nephritis; and in the breast and prostate, as in the kidney, the formation of fibrous tissue leads to changes in the secreting epithelium resulting in the formation of cysts.

Lastly, there are still other types of chronic inflammation attended with the formation of fibrous tissue on such a liberal scale as to suggest analogies with new growths.  The best known of these are the systematic forms of fibromatosis met with in the central nervous system and in the peripheral nerves—­neuro-fibromatosis; in the submucous coat of the stomach—­gastric fibromatosis; and in the colon—­intestinal fibromatosis.

These conditions will be described with the tissues and organs in which they occur.

In the treatment of chronic inflammations, pending further knowledge as to their causation, and beyond such obvious indications as to help the tissues by removing a foreign body or a piece of dead bone, there are employed—­empirically—­a number of procedures such as the induction of hyperaemia, exposure to the X-rays, and the employment of blisters, cauteries, and setons.  Vaccines may be had recourse to in those of bacterial origin.

CHAPTER IV

SUPPURATION

Definition—­Pus—­Varieties—­Acute circumscribed abscess—­Acute
    suppuration in a wound—­Acute Suppuration in a mucous
    membrane—­Diffuse cellulitis and diffuse suppuration—­
    Whitlow—­Suppurative cellulitis in different situations—­Chronic
    suppuration—­Sinus, Fistula—­Constitutional manifestations of
    pyogenic infection—­Sapraemia—­Septicaemia—­Pyaemia.