Causes: inflammation, exudation, obstructed circulation, lesions in
trophic nerve centres, sclerosis, toxins, ergot, caustics, freezing,
gangrene, microbes, cryptogams, spoiled fodder, white skins,
buckwheat, insolation. Symptoms: inflammation, molecular
disintegration, dry sloughs. Treatment: camphorated spirit or
vaseline, antiseptics, phenol, salicylic acid, iodoform, iodine,
creolin, lysol, tar, detach sloughs.
In all cases in which the skin is violently inflamed, and particularly
when the seat of an abundant exudation or infiltration which blocks
circulation and retards nutrition, the tissues are especially liable to
death, molecular or by sloughing, and formation of bedsores. As a
general cause lesions of the trophic centres in the medulla and cord
must be accepted as a cause of the imperfect nutrition and lack of
vitality. This is seen in sclerosis of the cord, but may appear as the
result of poisoning of the myelon as well as the gangrenous tissues by
absorbed toxins. Again a common cause of circumscribed cutaneous
gangrene is the capillary contraction and obstruction of ergotism. This
usually involves all the tissues, soft and hard, at the distal end of a
member or organ, causing the separation of all at one common level, but
in less severe forms the skin only sloughs, in the form of round or
irregular masses, usually around the coronet, and the resulting sores
heal up under an appropriate diet. Cauterization and freezing may be a
further occasion of gangrene. Finally, the local operation of the
microbes of gangrene, determines both ulceration and sloughing.
Cryptogams on spoiled fodders (trefoil, lupins, vetches, rusty gramineæ)
are also charged with developing gangrene.
White skins or white patches on the skin are especially liable to suffer
as in cases of fagopyrism and “grease”. The action of the solar rays in
summer must therefore be accepted as a concurrent cause.
_Symptoms._ The first symptoms are usually those of cutaneous congestion
or inflammation. Redness, swelling, pitting on pressure, or tension, are
accompanied or followed by vesicles, chaps or erosions. The margins of
the sores become thick and irregular, often undermined, and they
gradually increase by breaking down of tissue in their depth or on their
margin. In other cases patches of skin dry or wither up, either in
superficial layer or throughout its entire thickness, and these dried
extra vascular sloughs are gradually detached by granulation beneath.
The surrounding tumefaction is always extensive and the sores may expose
the deep seated structures—tendons, ligaments, fascia, bones,
joints—causing widespread destruction.
_Treatment._ If the disease is due to capillary occlusion of nervous
origin, compresses with camphorated spirit, followed by camphorated
vaseline may be of advantage. If otherwise, antiseptics will be in
order: carbolated vaseline, salicylic acid cream, iodoformed vaseline, a
weak iodine ointment, creolin, or lysol in water, tar water. When the
dead tissues are partially separated the detachment may be hastened with
knife or scissors and the sores treated like a septic sore.