M.—S. Rub in twice daily. There is another mildly alkaline tarry preparation, the goudron de Guyot, somewhat similar in composition to the liquor picis alkalinus, which at times seems to suit when the other tarry applications fail to benefit.
In the treatment of eczema rubrum of the legs Hebra was in the habit of employing the following method: A small quantity of the green soap is to be rubbed into the parts with a flannel rag, employing considerable friction, until all the soap has apparently disappeared; then warm or hot water is to be added and rubbed in in the same manner, an abundant lather being the result. The parts after being rubbed for from five to fifteen minutes, according to the effect, are to be thoroughly rinsed off with simple warm water, and a mild ointment, spread upon cloths, applied. The best ointment for this purpose is the unguentum diachyli, but any mild ointment may be employed. This treatment is to be repeated once or twice daily. In most cases improvement sets in after a few applications. It is an excellent method of treatment, and can be recommended. It requires considerable time and trouble, however, and is therefore not suitable in all cases, for unless the details are properly carried out it may fail.
Salicylic acid is another remedy that is often useful. In thick, leathery patches, an ointment of the strength of thirty to sixty grains to the ounce, applied on cloths or rubbed in, will often produce marked benefit. In the form of a paste it may be used in many cases of subacute and chronic eczema with good effects:
| Rx. | Acidi salicylici, | gr. xx; |
| Ugt. petrolei, | drachm iv; | |
| Amyli, Zinci oxidi, aa. | drachm ij. |
M.—S. Apply once or twice daily. If it is used upon the scalp, it should be used with petroleum ointment or lard, the starch and zinc oxide being omitted. Boric acid in the form of a saturated solution, as advised in acute eczema, or in ointment of the strength of a drachm to the ounce, will prove useful in some instances. Sulphur in the form of ointment may also be mentioned as being frequently of value in cases of chronic eczema, especially of the leg. In some cases of subacute and chronic eczema the lotion containing zinc sulphate and potassium sulphide, diluted, mentioned in acne, will be found serviceable. In circumscribed and chronic patches blistering with cantharides is sometimes advisable. In these cases tincture of iodine is also employed. In thickened patches, rebellious to the usual remedies, chrysarobin or pyrogallic acid, as used in psoriasis, may sometimes be applied with benefit.
Mention may here be made of vulcanized india-rubber, used in the form of bandages, the method proving of most value in eczema of the lower extremities, especially in those cases which are due to a condition of varicose veins. It is not suitable in all cases, as in some the disease is aggravated. Reference may also be made to the use of the so-called gelatin dressing. The medicinal substance is incorporated with the gelatin basis, which is made by melting together over a water-bath two parts of water and one of gelatin; and when the application is made the gelatin compound is melted over a water-bath and applied while in the fluid condition; it rapidly hardens and forms an impermeable coating to the diseased part. The dressing is liable to crack, to avoid which, in a measure, a small quantity of glycerin is mixed with the gelatin and water. Another plan is, after the dressing has dried, to brush over the surface a few minims of glycerin. It has, however, cleanliness in its favor, and it is undoubtedly of service in many instances. A good basis formula for the gelatin dressing consists of eight parts of water, four of gelatin, and one of glycerin.
Another form of fixed dressing for scaly patches is with collodion. This may often be made use of when tar is employed, the addition of one or two drachms of pix liquida or one of the tar oils to enough collodion to make an ounce. Such a preparation may be applied to dry and scaly patches, and constitutes an excellent method of application; but tar so applied is not as efficient as when used in solution or in ointment. The gutta-percha and muslin plasters3 constitute excellent methods of applying remedies; they are cleanly, easily applied, comfortable to the patient, and efficacious.
3 These plasters were devised by Unna, and are made by Beiersdorf, an apothecary of Hamburg, Germany. The muslin plasters consist of muslin incorporated with a layer of stiff ointment; the gutta-percha plasters consist of muslin faced with a thin layer of india-rubber, the medication being spread upon the rubber coating.
Prurigo.