Treatment. This is essentially the same as for the white face and foot disease with this additional that the buckwheat or other offensive ingredient must be withdrawn from the ration, and what remains in the bowels must be expelled by saline or other laxative. Cooling diuretics must follow to eliminate irritant matters that may have been absorbed.
ERYTHEMA FROM IRRITANTS.
Irritant agents of all kinds, even if caustic or pustulant in concentrated forms, may be so diluted as to cause simple erythema. Among chemical agents we have ammonia, lye, caustic acids and salts, iodine, carbolic acid, the various tar products, kerosene, aniline, chloroform, ether, formaline, etc. Of thermic irritants may be named solar heat, fire heat, steam, hot water, hot air, and congelation (chillblains, freezing) the latter being especially common in the digital region when salt has been applied to snow or ice. Vegetable irritants include mustard, capsicum, moulds, euphorbium, rhus, milkwort, the volatile oils, etc. Among animal irritants must be named cantharides, mylabris, potato beetle, insect stings, venom of the irritated toad, liquid discharges from the kidneys or bowels, and discharges from open sores. Even the escape of tears upon the face will cause erythema.
The symptoms in all such cases will vary with the potency of the factor and the susceptibility of the skin. Beside the common symptoms the color and odor of the skin will often yield valuable diagnostic indications. There is the white of muriatic acid, carbolic acid or zinc chloride, the black of silver salts or sulphuric acid, the yellow of iodine, chromium compounds and nitric acid, the well known odors of ammonia, iodine, chlorine, carbolic acid, tar, essential oils, chloroform, ether, formaline, kerosene, mustard, etc.
Treatment is that of simple erythema after one has applied the appropriate antidote to the particular irritant. For the alkalies and carbolic acid use vinegar, for the acids oxide or carbonate of magnesia, chalk or lime water, for iodine and chlorine weak alkaline solutions, for rhus, ammonia or other alkali, or potassium permanganate, and for insect stings and animal venoms, alkalies or permanganates. The caustic salts may demand milk, white of egg, or some other albuminous solution. When no chemical antidote is available, the first step is to wash off the offending agent, and then treat the erythema.
DERMATITIS.
Under this head may be included a class of inflammations of the skin, due mainly or entirely to external causes, not essentially parasitic, and attended by distinct eruptions (papular, vesicular, pustular, etc.). Many of these are but an advance beyond the simple erythematous inflammation, and coincide with it, the one condition being present at one part of the diseased area, and the more advanced and severe lesions at another part. Bearing in mind the frequency of this connection, it will be unnecessary to dwell at length on this class of affections.
Dermatitis Traumatica. Dermatitis from Mechanical Injury. Besides the veritant factors already named as causing traumatic erythema, we must here recognize contusions, over-reaching, treads, interfering, bruising and chafing by harness, girths, circingles, hobbles, ropes, traces, twists, and blows with whip, club, chain or rope. Here the source of injury must be removed, by attention to shoeing, harness, etc., and the lesions treated according to their gravity as simple wounds.
Dermatitis Venenata: Dermatitis Calorica. These, like the corresponding erythema, come from contact with irritant plants or animals or their products, from excessive heat or cold, and may show any grade of eruption or even gangrene and sloughing. Apart from the washing off of the irritant or venomous matter and the application of alkalies or permanganates in the case of the latter, these must be treated like ordinary sores. In burns, especial value attaches to solutions of sodium bicarbonate, and preparations that will exclude the air. Vesicles may be emptied by puncture and the part covered with cotton soaked in carbolated sweet oil and lime water, or carron oil (linseed oil and lime water) may be freely applied, or a resorcin solution (2:100 water), or a thick varnish of linseed oil and litharge, equal parts, with 5 per cent. of salicylic acid, melted and painted over the surface. A layer of surgeon’s cotton covered by a rubber bandage where admissible, will complete the dressing. In the process of healing, skin grafting may be required. Thin slices of cuticle are placed in the center of the granulating surface, or at intervals and carefully bound in place.
When a part has been frozen the usual method is to recover circulation slowly by rubbing with cold water or snow. The parts are then treated by astringent and antiseptic dressings. If the skin sloughs use antiseptics until it separates, and then treat like an ordinary sore.