In some cases, more particularly in strong, hearty, plethoric persons, and in those having a rheumatic or gouty habit, the free use of alkalies proves of great value. In these cases arsenic often aggravates rather than improves the condition, whereas the alkali acts most happily. It may be recommended in acute stages of the disease when the lesions are red, heated, and growing. Liquor potassæ, in from ten to twenty drop doses, diluted with a large wineglassful of water, thrice daily, is the form generally prescribed. Improvement is sometimes noted within a few days. Anderson calls attention also to the value of carbonate of ammonium, in from ten to thirty grain doses, in like cases. The acetate of potassium, in thirty-grain doses, may also be referred to as being sometimes useful.
Local treatment may now be considered. This is of great value, and should be instituted in all cases, either alone or in conjunction with internal remedies, according to the case. Sometimes it may be directed alone with good results, more particularly in chronic, sluggish cases where the lesions undergo but little change from time to time and are unaccompanied by subjective symptoms. Before prescribing certain points should be ascertained. The duration of the disease; the extent of the eruption, including the number and size of the lesions, and their acuteness or chronicity; the locality involved; the circumstances and the age of the patient; and the time that can be given to the treatment,—should all be taken into consideration. In this connection it should be remembered that whatever plan of treatment is adopted, the remedies should be applied thoroughly. The disease at best yields stubbornly, and to secure satisfactory results the importance of employing the agents properly should be insisted upon. This requires in most instances considerable time once, and, in some cases, twice a day. The scales are to be removed first. Where they are thick and adherent, inunction with some simple oil, as olive oil, followed by the use of soap and water, may be employed. Ordinarily, soft soap alone, well rubbed into the lesions with a piece of wet flannel and rinsed off with water, will be found sufficient. A 5 or 8 per cent. alcoholic solution of salicylic acid may be employed for the same purpose. The bath, simple or alkaline—the latter containing, for example, borax—is also frequently of service.
In acute, highly inflammatory cases, where the skin is red, hot, scaling profusely, and the lesions spreading from day to day, soothing applications, as of olive oil, will generally prove most valuable. Instances are sometimes encountered where the use of the simple bath, followed by inunctions of olive oil or one of the petroleum ointments, will prove to be the only treatment tolerated. The majority of cases, however, seeking advice show the disease already well developed and in the chronic stage, and here stimulating remedies are demanded.
One of the most valuable and generally useful remedies is tar, employed in the form of ointment or tincture or in combination with other substances, as, for example, the mercurials or sulphur. The tarry products in common use are pix liquida, or common tar, oil of tar, oil of cade, and oleum rusci (oil of white birch). The chief objection to their employment is the penetrating odor, which is almost impossible to banish. The oil of birch is probably the least objectionable in the list. Officinal tar ointment, full strength or weakened, will be found serviceable. It should be applied with a piece of cloth or stiff brush, well rubbed into the skin, and should be used twice daily, the scales having been previously removed by one or another of the methods indicated. Similar ointments, one or two drachms to the ounce, may in like manner be prepared from any of the other preparations of tar, as, for instance, the oil of white birch. Where an ointment is not desired, the oil of tar, oil of cade, or oil of white birch may be employed, the remedy being thoroughly rubbed or worked into the skin. Attention to the mode of application should always be insisted upon.
Other tarry preparations, such as liq. picis alkalinus, liq. carbonis detergens (the formulæ for which have been given in speaking of the treatment of eczema), diluted, may also be prescribed in some cases with benefit. Hebra's modification of Wilkinson's ointment may be referred to as an energetic and useful compound:
| Rx. | Sulphuris sublimati, Ol. cadini, aa. | drachm iv; |
| Saponis viridis, Adipis, aa. | ounce j; | |
| Cretæ præparatæ, | drachm ijss. | |
| M. Ft. ugt. | ||
Another method of using tar consists in the so-called tar bath: the patches are deprived of scales by means of soft soap, after which tar ointment or one of the tarry oils is rubbed in, and the patient then placed in a warm bath for several hours. A stimulating tarry mixture, especially useful in circumscribed, infiltrated, obstinate patches, is composed of equal parts of tar, soft soap, and alcohol. Tar should not be applied over extensive surfaces without cautioning the patient that systemic disturbance, produced by absorption, may possibly occur. In ordinary cases, however, such an accident is very rarely noted. Creasote, turpentine, and acetic acid, remedies similar to tar in their action on the skin, may also be mentioned. The first-named may be used in the form of an ointment, from one to four drachms to the ounce. Turpentine may be applied pure or with oil, one to two or three parts. In some cases thymol in the form of an ointment, from five to thirty grains to the ounce, proves of service. The mercurials may also be referred to, but it may be stated that they are not as valuable in this disease as they are in eczema. The most useful is white precipitate in the form of ointment, from forty to eighty grains to the ounce, which is especially valuable in psoriasis of the scalp and of the face. Lotions of corrosive sublimate will also sometimes be found of service.
The treatment of psoriasis by chrysarobin—or chrysophanic acid, as it was originally termed—may now be referred to. It is a very valuable method of treatment. Care should be exercised in the selection of a reliable preparation, there being considerable difference in the strength, and therefore in the results obtained, of the remedy as found in the shops. Its disadvantages must be mentioned: It is liable to irritate and inflame the skin, causing sometimes an acute dermatitis or a follicular or furuncular inflammation and a variegated purplish or mahogany-colored staining of the skin. The hair, nails, and the linen of the patient also become stained. It may be prescribed in the form of an ointment, from ten grains to one drachm to the ounce of lard or petroleum ointment. The most desirable mode of application, that which is least objectionable, is in the form of a pigment, with flexible collodion or liquor gutta-perchæ, in the same strength as the ointment mentioned. It should be applied with a brush daily or every other day. The following formula, suggested by G. H. Fox, may be given: Chrysarobin and salicylic acid, each ten parts; ether, fifteen parts; collodion, enough to make one hundred parts. Another valuable remedy, having a similar action, to be used in the same manner as chrysarobin, is pyrogallic acid. Like chrysarobin, it stains the skin (a brownish hue), but it possesses the advantage over that substance in not being so irritating. Neither of these remedies, especially the pyrogallic acid, should be applied over extensive surfaces, on account of liability to absorption and systemic poisoning.
Where the patches are not numerous a solution of sulphide of lime may sometimes be used with excellent results, as according to the following formula, known as Vleminckx's solution:
| Rx. | Calcis, | ounce ss; |
| Sulphuris sublimati, | ounce j; | |
| Aquæ, | fluidounce x. | |
| Coque ad fluidounce vj, deinde filtra. | ||