Part 84

=Diuretics= are often beneficial in eliminating from the system the irritant products generated from disorders in sanguification, digestion, urinary secretion and hepatic function, as well as those that are derived from the cutaneous disorder. They tend further to reduce any existing fever, and to cool and relieve the burning integument. The alkaline diuretics are often very useful.

=Purgatives= act in a similar way and are especially indicated in cases due to ingested irritants, and in such as depend on morbid products of gastro-intestinal or hepatic disorder. In many acute attacks these may be said to be almost specific in their action as in urticaria, and in the eruptions due to distillery products or green food.

=Tonics= are often called for to correct dyspepsias, to improve the general health and vigor, the sanguification and nutrition in weak and debilitated conditions. Iron, cod liver oil, bitters, quinia, quassia, calumba, gentian, nux, are often of value in such cases.

=Alteratives.= =Arsenic= may be said to act as a tonic with a special tendency toward the skin where it affects the epidermis and epidermic products and is applicable to many subacute and chronic disorders, as psoriasis, acne, dry eczema, and pemphigus. It has been further supposed to be most useful in superficial lesions, and in those due to a neurotic origin, from the known operation of arsenic on the nerves. It is little suited to acute skin diseases, and though often valuable is not to be trusted as universally applicable.

=Sulphur= is often useful as a laxative, but also as a stimulant to the cutaneous secretions when these are impaired.

=Antimony= is similarly a cutaneous stimulant and is sometimes useful in chronic inactive conditions.

=Phosphorus= has been found useful in obstinate cases and probably acts on the nerve centres in improving nutrition of the integument.

=Calcium sulphide= is sometimes useful with free secretion from the diseased surface, but its action is somewhat uncertain.

=Pilocarpin= operates by securing free secretion from the skin as well as from the various mucosæ, and seems to benefit by elimination, as well as by modifying the cutaneous functions and nutrition.

=Local Applications.= =Baths= may be placed foremost among these. Cleanliness is a prime necessity in treating skin disease. Tepid or warm water is especially required in acute disease in sensitive skins. In chronic cases with accumulation of scabs a soap wash following a 24 hours inunction with oil or lard may be demanded, but as a rule castile or other non-caustic soap should be used. In certain cases the baths may be advantageously medicated, as with calcium sulphide, potassium sulphide, salt, alum, tannic acid, tar, creolin, lysol, cresol, chloro-naphtholeum, arsenic, mercury, etc. The water alone is, however, of great value in soothing and moderating inflammation, softening and dissolving scabs and epidermis, and relieving the dryness and rigidity.

=Emollients= are used for the same end as calmatives, and relaxing and protective agents. Fatty bodies occupy a front rank, the bland vegetable and animal oils being not only soothing but nutritive (cod, lard, olive, cotton, almond, linseed, rape, pea nut, lanolin, neats foot and goose oil). Care should be taken that these are pure and in no sense rancid. Vaseline or petrolatum are free from the risk of rancidity, yet it should be free from contamination unless a stimulating action is wanted. Glycerine often used as an emollient has the disadvantage of drawing water from the surface and of actually irritating some sensitive skins. Glycerol made with glycerine and starch is more soothing. Glycogelatine made with glycerine 5, gelatine 3, and water 9, is very emollient and protective. This can be made the basis of astringent, sedative and antiseptic preparations by adding zinc oxide, lead acetate, chrysarobin, salicyclic acid, tannin, sulphur, oil of birch or of tar, etc. An excellent emollient paste is compounded of zinc oxide and vaseline one-half ounce of each, salicylic acid, ten grains. Oleate of lead is an excellent sedative application in irritation or pruritus.

=Drying powders= are found in starch, talc, magnesia, zinc oxide, lycopodium, bismuth oxide, boric acid, iodoform, aristol, salicylic acid, tannin, and, above all, magnesia carbonate. A slight addition of morphia sulphate will render them analgesic. Tar in zinc oxide or bismuth will secure antiseptic and stimulating qualities.

=Protective films= for irritable surfaces may be had from collodion, or from a solution of gutta percha in chloroform 1 ∶ 10 (traumaticin).

=Stimulating and antiseptic applications= are found in tar or oil of tar in suitable excipient and of a strength suited to the case, oil of white birch, oil of lavender, oil of cade, oil of cashew nut, oil of juniper, oil of hemlock, Canada balsam, balsam of Tolu or Peru, creolin, lysol, cresyl, creosote, carbolic acid, chloro-naphtholeum, etc. Ichthyol, of great value in chronic affections, may be used in oil or vaseline (5 ∶ 100), or in the form of Nuna’s varnish: Ichthyol 40, starch 40, concentrated albumen solution 1 to 1½, and water 20. Add the water to the starch, then rub in the ichthyol and finally the albumen. Resorcin is a useful stimulant, alterative, and antipruritic (1 ∶ 30 alcohol and oil).

As =antiseptics= and =parasiticides=, in addition to the above, are alpha- and beta-naphthol, iodized phenol, chloral camphor (rub together till they form a clear fluid), phenol camphor (add camphor gradually to the melted phenol crystals), mercuric chloride, cupric sulphate and silver nitrate. Potash (green) soap, medicated or not with tar or other agent, is of great use in many chronic affections. The phenol combinations are all more or less anæsthetic, and therefore sedatives and antipruritic. Quassia, Stavesacre, tobacco, etc., are of great use in parasitisms though not antiseptic. Sulphur fills both indications, and is a bland generally applicable agent.

=Caustics= (silver nitrate, antimony chloride, electric or thermocautery) are useful in luxuriant granulations, hyperplasias, and often in excessive secretion, or on infected surfaces.

=Counter-irritation= over the vaso-motor centres, is often of value, when the distribution of the eruption coincides with that of particular nerves, and indicates a nervous element in the causation.

=Bandages= of various kinds may be demanded to afford support in threatened dropsical effusion or excessive granulation or hyperplasia, to protect the surface against outside infection, to confine volatile applications to the affected part, and to prevent injury from biting, licking, scratching, or rubbing.

For the same reason it may be desirable to employ a muzzle, beads on the neck, tying to two opposite rings by short halters, hobbles, or other means of restraint.

ERYTHEMA. ERYTHEMATOUS DERMATITIS.

Definition, congestion, heat, redness, tenderness without eruption. Sheep: swine: dogs: white horses and cattle. Causes: slight irritants. Symptoms: congestion momentarily effaced by pressure, may go on to a distinct irruption.

Definition. Congestion of the papillary and adjacent layers of the skin with heat, redness, and tenderness, or a diffuse superficial inflammation with some superadded swelling.

Genera susceptible. The affection is seen in sheep, swine, dogs, and in white horses and cattle or on white parts of the skin. It is not readily recognized on pigmented parts.

Causes. The action of any slight irritant: pressure, friction, brushing, currying, blows, vesicants, rubefacients, stings, parasitism, radiant heat, intense sunshine, cold (reaction), storm, plunging in cold streams when heated, feeding on stimulating agents, notably buckwheat.

Symptoms. On white skins there is a uniformly diffused redness, without papule or other eruption, and the color may be momentarily effaced leaving a perfectly white spot, made by the pressure of the finger. The affected part is warm, tender, and it may be, itchy. It may be but the first step of a distinct eruption of another kind, such as variola, vesicles, papules, pustules, but then the affection takes a different name. It has been named according to its seat, cause and nature as follows:

INTERTRIGO. INTERTRIGO OF CHAFING.

Causes: friction, inside thighs, side of scrotum or mammæ, inner side of elbow, between digits on clipped heels, under harness. Dried sebum, sweat, dust, clay. Pricks with stubble. Symptoms: lameness on starting, abduction, straddling, knuckling, steps on toe. Treatment: abate cause, cleanse, rest, dusting powders, zinc, lycopodium, magnesia, starch, bismuth, alum, lead, morphia, surgeon’s cotton. Carron oil, vaseline, antiseptics.

This occurs where the folds of skin come in contact and rub on each other as between the thighs or beside the scrotum, sheath or mammæ in fat horses and other animals, on inner side of the elbow, between the digits in ruminants, on clipped heels in horses, and under harness. Irritant perspiration and sebaceous matter dried on, and mixed with more or less gritty or septic road dust contribute to it. Drying of clay and mud in the cleft of the frog, or in the interdigital space of ruminants is a common cause, also pricking with stubble.